Proportional Hazards Models
Risk Factors
Cohort Studies
Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.
Follow-Up Studies
Prospective Studies
Prognosis
Survival Analysis
A class of statistical procedures for estimating the survival function (function of time, starting with a population 100% well at a given time and providing the percentage of the population still well at later times). The survival analysis is then used for making inferences about the effects of treatments, prognostic factors, exposures, and other covariates on the function.
Kaplan-Meier Estimate
A nonparametric method of compiling LIFE TABLES or survival tables. It combines calculated probabilities of survival and estimates to allow for observations occurring beyond a measurement threshold, which are assumed to occur randomly. Time intervals are defined as ending each time an event occurs and are therefore unequal. (From Last, A Dictionary of Epidemiology, 1995)
Incidence
Retrospective Studies
Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.
Survival Rate
Multivariate Analysis
Risk Assessment
Treatment Outcome
Predictive Value of Tests
In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.
Risk
Cause of Death
Age Factors
Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.
Neoplasm Staging
Confidence Intervals
Disease-Free Survival
Longitudinal Studies
Cardiovascular Diseases
Registries
SEER Program
A cancer registry mandated under the National Cancer Act of 1971 to operate and maintain a population-based cancer reporting system, reporting periodically estimates of cancer incidence and mortality in the United States. The Surveillance, Epidemiology, and End Results (SEER) Program is a continuing project of the National Cancer Institute of the National Institutes of Health. Among its goals, in addition to assembling and reporting cancer statistics, are the monitoring of annual cancer incident trends and the promoting of studies designed to identify factors amenable to cancer control interventions. (From National Cancer Institute, NIH Publication No. 91-3074, October 1990)
Questionnaires
Sex Factors
Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.
Disease Progression
Neoplasm Recurrence, Local
Confounding Factors (Epidemiology)
Factors that can cause or prevent the outcome of interest, are not intermediate variables, and are not associated with the factor(s) under investigation. They give rise to situations in which the effects of two processes are not separated, or the contribution of causal factors cannot be separated, or the measure of the effect of exposure or risk is distorted because of its association with other factors influencing the outcome of the study.
Tumor Markers, Biological
Molecular products metabolized and secreted by neoplastic tissue and characterized biochemically in cells or body fluids. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids.
Kidney Failure, Chronic
The end-stage of CHRONIC RENAL INSUFFICIENCY. It is characterized by the severe irreversible kidney damage (as measured by the level of PROTEINURIA) and the reduction in GLOMERULAR FILTRATION RATE to less than 15 ml per min (Kidney Foundation: Kidney Disease Outcome Quality Initiative, 2002). These patients generally require HEMODIALYSIS or KIDNEY TRANSPLANTATION.
Stroke
A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to BRAIN ISCHEMIA or INTRACRANIAL HEMORRHAGES. Stroke is classified by the type of tissue NECROSIS, such as the anatomic location, vasculature involved, etiology, age of the affected individual, and hemorrhagic vs. non-hemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)
Comorbidity
The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival.
Body Mass Index
An indicator of body density as determined by the relationship of BODY WEIGHT to BODY HEIGHT. BMI=weight (kg)/height squared (m2). BMI correlates with body fat (ADIPOSE TISSUE). Their relationship varies with age and gender. For adults, BMI falls into these categories: below 18.5 (underweight); 18.5-24.9 (normal); 25.0-29.9 (overweight); 30.0 and above (obese). (National Center for Health Statistics, Centers for Disease Control and Prevention)
European Continental Ancestry Group
Chi-Square Distribution
A distribution in which a variable is distributed like the sum of the squares of any given independent random variable, each of which has a normal distribution with mean of zero and variance of one. The chi-square test is a statistical test based on comparison of a test statistic to a chi-square distribution. The oldest of these tests are used to detect whether two or more population distributions differ from one another.
Odds Ratio
The ratio of two odds. The exposure-odds ratio for case control data is the ratio of the odds in favor of exposure among cases to the odds in favor of exposure among noncases. The disease-odds ratio for a cohort or cross section is the ratio of the odds in favor of disease among the exposed to the odds in favor of disease among the unexposed. The prevalence-odds ratio refers to an odds ratio derived cross-sectionally from studies of prevalent cases.
Myocardial Infarction
Renal Dialysis
Coronary Disease
Biological Markers
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
Severity of Illness Index
Colorectal Neoplasms
Lymphatic Metastasis
Epidemiologic Methods
Postmenopause
HIV Infections
Heart Failure
A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (VENTRICULAR DYSFUNCTION), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as MYOCARDIAL INFARCTION.
Neoplasms
African Americans
Regression Analysis
Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.
Age Distribution
Coffee
Models, Statistical
Alcohol Drinking
Diabetes Mellitus, Type 2
A subclass of DIABETES MELLITUS that is not INSULIN-responsive or dependent (NIDDM). It is characterized initially by INSULIN RESISTANCE and HYPERINSULINEMIA; and eventually by GLUCOSE INTOLERANCE; HYPERGLYCEMIA; and overt diabetes. Type II diabetes mellitus is no longer considered a disease exclusively found in adults. Patients seldom develop KETOSIS but often exhibit OBESITY.
Combined Modality Therapy
Antiretroviral Therapy, Highly Active
Analysis of Variance
CD4 Lymphocyte Count
Diabetes Mellitus
Chemotherapy, Adjuvant
Databases, Factual
Extensive collections, reputedly complete, of facts and data garnered from material of a specialized subject area and made available for analysis and application. The collection can be automated by various contemporary methods for retrieval. The concept should be differentiated from DATABASES, BIBLIOGRAPHIC which is restricted to collections of bibliographic references.
Sex Distribution
Case-Control Studies
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
Logistic Models
Statistical models which describe the relationship between a qualitative dependent variable (that is, one which can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. A common application is in epidemiology for estimating an individual's risk (probability of a disease) as a function of a given risk factor.
African Continental Ancestry Group
Hypertension
Survival
Prostate-Specific Antigen
Life Style
Hip Fractures
Diabetes Complications
Socioeconomic Factors
Treatment Failure
Age of Onset
Prostatectomy
Complete or partial surgical removal of the prostate. Three primary approaches are commonly employed: suprapubic - removal through an incision above the pubis and through the urinary bladder; retropubic - as for suprapubic but without entering the urinary bladder; and transurethral (TRANSURETHRAL RESECTION OF PROSTATE).
Randomized Controlled Trials as Topic
Genotype
Carcinoma, Squamous Cell
Ovarian Neoplasms
Receptors, Estrogen
Residence Characteristics
Anti-HIV Agents
Dementia
An acquired organic mental disorder with loss of intellectual abilities of sufficient severity to interfere with social or occupational functioning. The dysfunction is multifaceted and involves memory, behavior, personality, judgment, attention, spatial relations, language, abstract thought, and other executive functions. The intellectual decline is usually progressive, and initially spares the level of consciousness.
Biometry
Prevalence
Endometrial Neoplasms
Immunohistochemistry
Multicenter Studies as Topic
Health Surveys
Diet Surveys
Life Tables
Carcinoma, Hepatocellular
A primary malignant neoplasm of epithelial liver cells. It ranges from a well-differentiated tumor with EPITHELIAL CELLS indistinguishable from normal HEPATOCYTES to a poorly differentiated neoplasm. The cells may be uniform or markedly pleomorphic, or form GIANT CELLS. Several classification schemes have been suggested.
Neoplasm Grading
Estrogen Replacement Therapy
The use of hormonal agents with estrogen-like activity in postmenopausal or other estrogen-deficient women to alleviate effects of hormone deficiency, such as vasomotor symptoms, DYSPAREUNIA, and progressive development of OSTEOPOROSIS. This may also include the use of progestational agents in combination therapy.
Netherlands
Receptors, Progesterone
Specific proteins found in or on cells of progesterone target tissues that specifically combine with progesterone. The cytosol progesterone-receptor complex then associates with the nucleic acids to initiate protein synthesis. There are two kinds of progesterone receptors, A and B. Both are induced by estrogen and have short half-lives.
beta Carotene
A carotenoid that is a precursor of VITAMIN A. It is administered to reduce the severity of photosensitivity reactions in patients with erythropoietic protoporphyria (PORPHYRIA, ERYTHROPOIETIC). (From Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Engewood, CO, 1995.)
ROC Curve
Coronary Artery Disease
Aging
Glomerular Filtration Rate
Carcinoma, Non-Small-Cell Lung
Data Interpretation, Statistical
Antineoplastic Combined Chemotherapy Protocols
Outcome Assessment (Health Care)
Polymorphism, Single Nucleotide
Reproducibility of Results
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
Medicare
Federal program, created by Public Law 89-97, Title XVIII-Health Insurance for the Aged, a 1965 amendment to the Social Security Act, that provides health insurance benefits to persons over the age of 65 and others eligible for Social Security benefits. It consists of two separate but coordinated programs: hospital insurance (MEDICARE PART A) and supplementary medical insurance (MEDICARE PART B). (Hospital Administration Terminology, AHA, 2d ed and A Discursive Dictionary of Health Care, US House of Representatives, 1976)
Radiotherapy, Adjuvant
Death, Sudden, Cardiac
Unexpected rapid natural death due to cardiovascular collapse within one hour of initial symptoms. It is usually caused by the worsening of existing heart diseases. The sudden onset of symptoms, such as CHEST PAIN and CARDIAC ARRHYTHMIAS, particularly VENTRICULAR TACHYCARDIA, can lead to the loss of consciousness and cardiac arrest followed by biological death. (from Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 7th ed., 2005)
Death
Pancreatic Neoplasms
Tumors or cancer of the PANCREAS. Depending on the types of ISLET CELLS present in the tumors, various hormones can be secreted: GLUCAGON from PANCREATIC ALPHA CELLS; INSULIN from PANCREATIC BETA CELLS; and SOMATOSTATIN from the SOMATOSTATIN-SECRETING CELLS. Most are malignant except the insulin-producing tumors (INSULINOMA).
Brain Neoplasms
Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.
Dairy Products
C-Reactive Protein
Survivors
Neoplasm Metastasis
National Institutes of Health (U.S.)
Menopause
Ethnic Groups
Reproductive History
An important aggregate factor in epidemiological studies of women's health. The concept usually includes the number and timing of pregnancies and their outcomes, the incidence of breast feeding, and may include age of menarche and menopause, regularity of menstruation, fertility, gynecological or obstetric problems, or contraceptive usage.
Carcinoma, Renal Cell
Nomograms
Graphical representation of a statistical model containing scales for calculating the prognostic weight of a value for each individual variable. Nomograms are instruments that can be used to predict outcomes using specific clinical parameters. They use ALGORITHMS that incorporate several variables to calculate the predicted probability that a patient will achieve a particular clinical endpoint.
Chronic Disease
Diseases which have one or more of the following characteristics: they are permanent, leave residual disability, are caused by nonreversible pathological alteration, require special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care. (Dictionary of Health Services Management, 2d ed)
Obesity
A status with BODY WEIGHT that is grossly above the acceptable or desirable weight, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).
Biostatistics
Double-Blind Method
Pregnancy
Genetic Predisposition to Disease
Population Surveillance
Dietary Supplements
Products in capsule, tablet or liquid form that provide dietary ingredients, and that are intended to be taken by mouth to increase the intake of nutrients. Dietary supplements can include macronutrients, such as proteins, carbohydrates, and fats; and/or MICRONUTRIENTS, such as VITAMINS; MINERALS; and PHYTOCHEMICALS.
Neoplasms, Second Primary
Abnormal growths of tissue that follow a previous neoplasm but are not metastases of the latter. The second neoplasm may have the same or different histological type and can occur in the same or different organs as the previous neoplasm but in all cases arises from an independent oncogenic event. The development of the second neoplasm may or may not be related to the treatment for the previous neoplasm since genetic risk or predisposing factors may actually be the cause.
Bias (Epidemiology)
Any deviation of results or inferences from the truth, or processes leading to such deviation. Bias can result from several sources: one-sided or systematic variations in measurement from the true value (systematic error); flaws in study design; deviation of inferences, interpretations, or analyses based on flawed data or data collection; etc. There is no sense of prejudice or subjectivity implied in the assessment of bias under these conditions.
Peritoneal Dialysis
Peripheral Arterial Disease
Hydroxymethylglutaryl-CoA Reductase Inhibitors
Graft Survival
Postoperative Complications
Occupational Exposure
British Columbia
A province of Canada on the Pacific coast. Its capital is Victoria. The name given in 1858 derives from the Columbia River which was named by the American captain Robert Gray for his ship Columbia which in turn was named for Columbus. (From Webster's New Geographical Dictionary, 1988, p178 & Room, Brewer's Dictionary of Names, 1992, p81-2)
Asian Continental Ancestry Group
Hawaii
A group of islands in Polynesia, in the north central Pacific Ocean, comprising eight major and 114 minor islands, largely volcanic and coral. Its capital is Honolulu. It was first reached by Polynesians about 500 A.D. It was discovered and named the Sandwich Islands in 1778 by Captain Cook. The islands were united under the rule of King Kamehameha 1795-1819 and requested annexation to the United States in 1893 when a provisional government was set up. Hawaii was established as a territory in 1900 and admitted as a state in 1959. The name is from the Polynesian Owhyhii, place of the gods, with reference to the two volcanoes Mauna Kea and Mauna Loa, regarded as the abode of the gods. (From Webster's New Geographical Dictionary, 1988, p493 & Room, Brewer's Dictionary of Names, 1992, p2330)
Adenocarcinoma, Mucinous
Carcinoma
Canada
Morbidity
Karnofsky Performance Status
A performance measure for rating the ability of a person to perform usual activities, evaluating a patient's progress after a therapeutic procedure, and determining a patient's suitability for therapy. It is used most commonly in the prognosis of cancer therapy, usually after chemotherapy and customarily administered before and after therapy. It was named for Dr. David A. Karnofsky, an American specialist in cancer chemotherapy.
Viral Load
Neoplasms, Glandular and Epithelial
Nurses
Continental Population Groups
Melanoma
A malignant neoplasm derived from cells that are capable of forming melanin, which may occur in the skin of any part of the body, in the eye, or, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites. It occurs mostly in adults and may originate de novo or from a pigmented nevus or malignant lentigo. Melanomas frequently metastasize widely, and the regional lymph nodes, liver, lungs, and brain are likely to be involved. The incidence of malignant skin melanomas is rising rapidly in all parts of the world. (Stedman, 25th ed; from Rook et al., Textbook of Dermatology, 4th ed, p2445)
Osteoporotic Fractures
Reoperation
Computer Simulation
Microvascular loops and networks as prognostic indicators in choroidal and ciliary body melanomas. (1/14874)
BACKGROUND: Malignant melanoma of the ciliary body and choroid of the eye is a tumor that disseminates frequently, and 50% of the diagnosed patients die within 10 years. We investigated the hypothesis that, by histopathologic analysis of the arrangement of microvessels (i.e., small blood vessels) in loops and networks, we might be able to differentiate better those patients with a favorable prognosis from those with a poor prognosis. METHODS: We conducted a population-based, retrospective cohort study of melanoma-specific and all-cause mortality for 167 consecutive patients who had an eye surgically removed because of malignant choroidal or ciliary body melanoma during the period from 1972 through 1981. Microvascular loops and networks were evaluated independently by two pathologists who were unaware of patient outcome. RESULTS: Microvascular patterns could be assessed in 134 (80%) of 167 melanoma specimens. The 10-year probability of melanoma-specific survival was worse if microvascular loops (0.45 versus 0.83; two-sided P<.0001) and networks (0.41 versus 0.72, two-sided P<.0001) were present. In multivariate Cox regression analysis of melanoma-specific survival, the hazard ratios were 1.66 (95% confidence interval [CI] = 1.19-2.30) for the presence of loops and networks as a combined three-category variable, 2.36 (95% CI = 1.37-4.05) for the presence of epithelioid cells, 1.11 (95% CI = 1.03-1.19) for the largest basal tumor diameter (evaluated as a continuous variable), and 2.14 (95% CI = 1.25-3.67) for ciliary body involvement. CONCLUSIONS: Patients with malignant uveal melanoma who have a favorable prognosis can be distinguished from those with a poor prognosis by histopathologic analysis of microvascular patterns in uveal melanoma tumor specimens. (+info)Effects of calcium-channel blockade in older patients with diabetes and systolic hypertension. Systolic Hypertension in Europe Trial Investigators. (2/14874)
BACKGROUND: Recent reports suggest that calcium-channel blockers may be harmful in patients with diabetes and hypertension. We previously reported that antihypertensive treatment with the calcium-channel blocker nitrendipine reduced the risk of cardiovascular events. In this post hoc analysis, we compared the outcome of treatment with nitrendipine in diabetic and nondiabetic patients. METHODS: After stratification according to center, sex, and presence or absence of previous cardiovascular complications, 4695 patients (age, > or =60 years) with systolic blood pressure of 160 to 219 mm Hg and diastolic pressure below 95 mm Hg were randomly assigned to receive active treatment or placebo. Active treatment consisted of nitrendipine (10 to 40 mg per day) with the possible addition or substitution of enalapril (5 to 20 mg per day) or hydrochlorothiazide (12.5 to 25 mg per day) or both, titrated to reduce the systolic blood pressure by at least 20 mm Hg and to less than 150 mm Hg. In the control group, matching placebo tablets were administered similarly. RESULTS: At randomization, 492 patients (10.5 percent) had diabetes. After a median follow-up of two years, the systolic and diastolic blood pressures in the placebo and active-treatment groups differed by 8.6 and 3.9 mm Hg, respectively, among the diabetic patients. Among the 4203 patients without diabetes, systolic and diastolic pressures differed by 10.3 and 4.5 mm Hg, respectively, in the two groups. After adjustment for possible confounders, active treatment was found to have reduced overall mortality by 55 percent (from 45.1 deaths per 1000 patients to 26.4 deaths per 1000 patients), mortality from cardiovascular disease by 76 percent, all cardiovascular events combined by 69 percent, fatal and nonfatal strokes by 73 percent, and all cardiac events combined by 63 percent in the group of patients with diabetes. Among the nondiabetic patients, active treatment decreased all cardiovascular events combined by 26 percent and fatal and nonfatal strokes by 38 percent. In the group of patients receiving active treatment, reductions in overall mortality, mortality from cardiovascular disease, and all cardiovascular events were significantly larger among the diabetic patients than among the nondiabetic patients (P=0.04, P=0.02, and P=0.01, respectively). CONCLUSIONS: Nitrendipine-based antihypertensive therapy is particularly beneficial in older patients with diabetes and isolated systolic hypertension. Thus, our findings do not support the hypothesis that the use of long-acting calcium-channel blockers may be harmful in diabetic patients. (+info)Association between age and survival following major amputation. The Scottish Vascular Audit Group. (3/14874)
OBJECTIVES: To determine whether age is associated with survival following major amputation and whether this association is independent or simply reflects selection bias in amputation level. DESIGN AND MATERIALS: Computer linkage of routine discharge and death data on the 2759 patients undergoing major amputation in Scotland between 1989 and 1993 for peripheral arterial disease. METHODS: Cox's proportional hazards model and multivariate logistic regression analysis using death as the outcome variable and age, sex, urgency, amputation level and recent arterial reconstructive surgery as predictor variables. RESULTS: Proximal amputation was more common in older patients. Survival was associated with both age (p < 0.001) and amputation level (p < 0.001). Age was an independent predictor of death at 30 days (p < 0.0001), 6 months (p < 0.001), 12 months (p < 0.0001) and 2 years (p < 0.0001) postoperation. CONCLUSIONS: Survival following amputation was poor, with only half the patients alive at 2 years. Above-knee amputation was associated with poorer survival, presumably due to the presence of more severe and widespread disease, and was undertaken more commonly in older patients. However, age remained a predictor of survival after adjustment for amputation level. Higher early mortality suggest that a worse prognosis in elderly patients cannot be attributed wholly to actuarial considerations. (+info)Prognostic value of ECG findings for total, cardiovascular disease, and coronary heart disease death in men and women. (4/14874)
OBJECTIVE: To study abnormalities in the resting ECG as independent predictors for all cause, cardiovascular disease (CVD), and coronary heart disease (CHD) mortality in a population based random sample of men and women, and to explore whether their prognostic value is different between sexes. DESIGN AND SUBJECTS: An age and sex stratified random sample was selected from the total Belgian population aged 25 to 74 years. Baseline data were gathered and resting ECGs were classified according to Minnesota code criteria. The sample was then followed for at least 10 years with respect to cause specific death. Results are based on observations from 5208 men and 4746 women free from prevalent CHD at the start of the follow up period. RESULTS: Although the prevalence of major abnormalities in general was comparable between sexes, women had more ischaemic findings, ST segment changes, and abnormal T waves on their baseline ECG, while men showed more arrhythmias, bundle branch blocks, and left ventricular hypertrophy. Fitting the multiplicative effect on subsequent mortality between all ECG classifications under study and sex indicated that the prognostic value of ECG changes was equal in women and men. Independently of other risk factors and other major ECG changes, almost all ECG classifications were significantly related to all cause, CVD, and CHD mortality. The most predictive ECG findings for CVD death were ST segment depression (risk ratio (RR) 4.71), major ECG findings (RR 3.26), left ventricular hypertrophy (RR 2.79), bundle branch blocks (RR 2.58), T wave flattening (RR 2.47), ischaemic ECG findings (RR 2.35), and arrhythmias (RR 2.15). The prognostic value of major ECG findings for CVD and CHD death was more powerful than well established cardiovascular risk factors. CONCLUSIONS: Abnormalities in the baseline ECG are strongly associated with subsequent all cause, CVD, and CHD mortality. Their predictive value was similar for men and women. (+info)Recurrence in affective disorder: analyses with frailty models. (5/14874)
The risk of recurrence in affective disorder is influenced by the number of prior episodes and by a person's tendency toward recurrence. Newly developed frailty models were used to estimate the effect of the number of episodes on the rate of recurrence, taking into account individual frailty toward recurrence. The study base was the Danish psychiatric case register of all hospital admissions for primary affective disorder in Denmark during 1971-1993. A total of 20,350 first-admission patients were discharged with a diagnosis of major affective disorder. For women with unipolar disorder and for all kinds of patients with bipolar disorder, the rate of recurrence was affected by the number of prior episodes even when the effect was adjusted for individual frailty toward recurrence. No effect of episodes but a large effect of the frailty parameter was found for unipolar men. The authors concluded that the risk of recurrence seems to increase with the number of episodes of bipolar affective disorder in general and for women with unipolar disorder. (+info)Influence of a family history of cancer within and across multiple sites on patterns of cancer mortality risk for women. (6/14874)
A case-control study nested within a large cohort, the American Cancer Society Cancer Prevention Study-1, was conducted to test associations between a family history of cancer and cancer mortality in women. By using logistic regression, the authors analyzed family history, as reported by 429,483 women enrolled in 1959, relative to subsequent mortality through 1972 from cancer within and across multiple sites. The associations between family history and cancer mortality were generally stronger within cancer sites than across cancer sites. Within-site associations were found for breast cancer (odds ratio (OR) = 1.9), colorectal cancer (OR = 1.6), stomach cancer (OR = 1.9), and lung cancer (OR = 1.7). Across-site associations were observed for a family history of 1) breast cancer as a risk factor for ovarian cancer mortality (OR = 1.6), 2) stomach cancer as a risk factor for ovarian cancer mortality (OR = 1.5), and 3) uterine cancer as a risk factor for pancreatic cancer mortality (OR = 1.6). A general pattern of positive associations was observed between a family history of cancer at several sites and subsequent death from pancreatic cancer. These findings support the growing body of evidence from cancer genetics suggesting that inherited cancer-susceptibility genes increase the risk for cancer at many sites and are not specific to cancer risk within a single site. (+info)Prognostic significance of extent of disease in bone in patients with androgen-independent prostate cancer. (7/14874)
PURPOSE: To evaluate the prognostic significance of a bone scan index (BSI) based on the weighted proportion of tumor involvement in individual bones, in relation to other factors and to survival in patients with androgen-independent prostate cancer. PATIENTS AND METHODS: Baseline radionuclide bone scans were reviewed in 191 assessable patients with androgen-independent disease who were enrolled onto an open, randomized trial of liarozole versus prednisone. The extent of skeletal involvement was assessed by scoring each scan using the BSI and independently according to the number of metastatic lesions. The relationship of the scored bone involvement to other known prognostic factors was explored in single- and multiple-variable analyses. RESULTS: In single-variable analyses, the pretreatment factors found to be associated with survival were age (P = .0446), performance status (P = .0005), baseline prostate-specific antigen (P = .0001), hemoglobin (P = .0001), alkaline phosphatase (P = .0002), AST (P = .0021), lactate dehydrogenase (P = .0001), and treatment (P = .0098). The extent of osseous disease was significant using both the BSI (P = .0001) and the number of lesions present (P = .0001). In multiple-variable proportional hazards analyses, only BSI, age, hemoglobin, lactate dehydrogenase, and treatment arm were associated with survival. When the patient population was divided into three equal groups, with BSI values of < 1.4%, 1.4% to 5.1%, and > 5.1%, median survivals of 18.3, 15.5, and 8.1 months, respectively, were observed (P = .0079). CONCLUSION: The BSI quantifies the extent of skeletal involvement by tumor. It allows the identification of patients with distinct prognoses for stratification in clinical trials. Further study is needed to assess the utility of serial BSI determinations in monitoring treatment effects. The BSI may be particularly useful in the evaluation of agents for which prostate-specific antigen changes do not reflect clinical outcomes accurately. (+info)Hematocrit level and associated mortality in hemodialysis patients. (8/14874)
Although a number of clinical studies have shown that increased hematocrits are associated with improved outcomes in terms of cognitive function, reduced left ventricular hypertrophy, increased exercise tolerance, and improved quality of life, the optimal hematocrit level associated with survival has yet to be determined. The association between hematocrit levels and patient mortality was retrospectively studied in a prevalent Medicare hemodialysis cohort on a national scale. All patients survived a 6-mo entry period during which their hematocrit levels were assessed, from July 1 through December 31, 1993, with follow-up from January 1 through December 31, 1994. Patient comorbid conditions relative to clinical events and severity of disease were determined from Medicare claims data and correlated with the entry period hematocrit level. After adjusting for medical diseases, our results showed that patients with hematocrit levels less than 30% had significantly higher risk of all-cause (12 to 33%) and cause-specific death, compared to patients with hematocrits in the 30% to less than 33% range. Without severity of disease adjustment, patients with hematocrit levels of 33% to less than 36% appear to have the lowest risk for all-cause and cardiac mortality. After adjusting for severity of disease, the impact of hematocrit levels of 33% to less than 36% is vulnerable to the patient sample size but also demonstrates a further 4% reduced risk of death. Overall, these findings suggest that sustained increases in hematocrit levels are associated with improved patient survival. (+info)
survival - Interval censored Cox proportional hazards model in R - Cross Validated
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FRI0145 The effect of adalimumab on risk of major adverse cardiovascular events in rheumatoid arthritis: A meta-analysis of...
SVR Improves Mortality 3-Fold - Association Between Sustained Virological Response and All-Cause Mortality Among Patients With...
Correlation of infusion-related reactions (IRR) and outcome in patients receiving NGR-HTNF treatment | OncologyPRO
Potential effect of various immunocompetent cells from | Open-i
存活分析(Survival analysis)介紹Ⅳ-Cox proportional hazard model (Cox regression)~晨晰統計林星帆顧問整理 @ 晨晰統計部落格新站(統計、SPSS、BIG DATA討論園地) :: 痞客邦...
name: T. Obel found 1 record • Arctic Health
Cardiovascular biomarkers in patients with cancer and their association with all-cause mortality | Heart
Cancer Research, Statistics, and Treatment
Clinical Application of Liquid Biopsies for Disease Monitoring and Understanding Therapeutic Resistance in Metastatic Breast...
STAT 311: Applied Survival Analysis: Mathematics and Statistics: Loyola University Chicago
Partially linear single index Cox regression model in nested case-control studies
Isomerases
Early presence of anti-angiogenesis-related adverse events as a potential biomarker of antitumor efficacy in metastatic gastric...
Hazard function synonyms, Hazard function antonyms - FreeThesaurus.com
SCMR 2020
Category: Survival analysis
JoVE Author Search: Caan BJ
R: Fit Proportional Hazards Regression Model
[email protected]: 장기요양 인정자의 최초 재가급여 선택과 유지 및 이탈에 대한 영향요인: Aging in Place 지원을 위한 탐색
[email protected]: 장기요양 인정자의 최초 재가급여 선택과 유지 및 이탈에 대한 영향요인: Aging in Place 지원을 위한 탐색
Applying Cox regression to competing risks
Wernroth, Lisa
AFib Patients Who Exercise Lower Mortality Risk, Live Longer: Study
Pushpa Publishing House
Plus it
Time-dependent mediators in survival analysis: Modeling direct and indirect effects with the additive hazards model -...
Higher muscle mass associated with lower mortality risk in people with heart disease | UCLA
The time to degree or dropout amongst full-time masters students at University of KwaZulu-Natal
Most recent papers with the keyword Health and fitness | Read by QxMD
Most recent papers with the keyword CRF | Read by QxMD
Qing Pan and Doug Schaubel, Lauréats du prix de La revue canadienne de statistique 2009 | Société statistique du Canada
Plus it
Longer Life Foundation : Cancer Patient-Specific Prognostic Information
r - Using strata instead of stratifying groups separately? - Cross Validated
CiteSeerX - Generalized Additive Models
Development and validation of a prediction rule for recurrent vascular events based on a cohort study of patients with arterial...
Applied Survival Analysis by Hosmer, Lemeshow and MayChapter 4: Interpretation of a Fitted Proportional Hazards Regression...
Survival Analysis I - Dalla Lana School of Public HealthDalla Lana School of Public Health
Proportional hazards model
The generic term parametric proportional hazards models can be used to describe proportional hazards models in which the hazard ... Proportional hazards models are a class of survival models in statistics. Survival models relate the time that passes, before ... For example, assuming the hazard function to be the Weibull hazard function gives the Weibull proportional hazards model. ... hazards models and Poisson regression models which is sometimes used to fit approximate proportional hazards models in software ...
Regression dilution
... and for some non-linear regression models. Other non-linear models, such as proportional hazards models for survival analysis, ... Hughes, M. D. (1993). "Regression dilution in the proportional hazards model". Biometrics. 49 (4): 1056-1066. doi:10.2307/ ... derived either directly by observation-with-error or from application of a measurement model, such as the Rasch model. Also, ... The case that x is fixed, but measured with noise, is known as the functional model or functional relationship. It can be ...
Survival analysis
The Cox model assumes that the hazards are proportional. The proportional hazard assumption may be tested using the R function ... For quantitative predictor variables, an alternative method is Cox proportional hazards regression analysis. Cox PH models work ... Cox models may be extended for such time-varying covariates. The Cox PH regression model is a linear model. It is similar to ... Tree-structured survival models may give more accurate predictions than Cox models. Examining both types of models for a given ...
Hazard ratio
Such models are generally classed proportional hazards regression models; the best known being the Cox proportional hazards ... Survival analysis Failure rate and Hazard rate Proportional hazards models Relative risk Najjar-Debbiny, R.; Gronich, N.; Weber ... If the proportional hazard assumption holds, a hazard ratio of one means equivalence in the hazard rate of the two groups, ... Regression models are used to obtain hazard ratios and their confidence intervals. The instantaneous hazard rate is the limit ...
Mare reproductive loss syndrome
"On the Use of the Accelerated Failure Time Model as an Alternative to the Proportional Hazards Model in the Treatment of Time ... Patel, K; Kay, R; Rowell, L (2006). "Comparing proportional hazards and accelerated failure time models: an application in ... Simino, J.; Hollander, M.; McGee, D. (2012). "Calibration of Proportional Hazards and Accelerated Failure Time Models". ... In most toxicological models, the effect is proportional to concentration of toxin or amount of insult. However, in the AFT ...
Customer attrition
Van Den Poel; Lariviére (2004). "Customer Attrition Analysis For Financial Services Using Proportional Hazard Models". European ... Several studies combine several different types of predictors to develop a churn model. This model can take demographic ... Since these models generate a small prioritized list of potential defectors, they are effective at focusing customer retention ... One of the main objectives of modeling customer churn is to determine the causal factors, so that the company can try to ...
Multicollinearity
"Customer attrition analysis for financial services using proportional hazard models". European Journal of Operational Research ... A principal danger of such data redundancy is that of overfitting in regression analysis models. The best regression models are ... Such a model is often called "low noise" and will be statistically robust (that is, it will predict reliably across numerous ... More importantly, the usual use of regression is to take coefficients from the model and then apply them to other data. Since ...
Hypertabastic survival models
If the sample consists of right censored data and the model to use is Hypertabastic proportional hazards model, then, the ... Hypertabastic Proportional Hazards Model with Log Time */ title1 'Kidney Carcinoma'; max logf; /* Model Parameter Initial ... was performed using the generalized chi-square test statistics and proportional hazards model. The Hypertabastic proportional ... The Hypertabastic proportional hazards model was used to analyze the survival time of patients diagnosed with kidney carcinoma ...
MedCalc
Survival analysis includes Cox regression (Proportional hazards model) and Kaplan-Meier survival analysis. Procedures for ...
Accelerated failure time model
... that would be the proportional hazards model. Unlike proportional hazards models, in which Cox's semi-parametric proportional ... AFT model) is a parametric model that provides an alternative to the commonly used proportional hazards models. Whereas a ... Unlike proportional hazards models, the regression parameter estimates from AFT models are robust to omitted covariates. They ... proportional hazards model assumes that the effect of a covariate is to multiply the hazard by some constant, an AFT model ...
Semiparametric model
These models often use smoothing or kernels. A well-known example of a semiparametric model is the Cox proportional hazards ... a semiparametric model is a statistical model that has parametric and nonparametric components. A statistical model is a ... However, a semiparametric model is considered to be "smaller" than a completely nonparametric model because we are often ... It may appear at first that semiparametric models include nonparametric models, since they have an infinite-dimensional as well ...
Nested case-control study
"Methods for the Analysis of Sampled Cohort Data in the Cox Proportional Hazards Model" (PDF). Annals of Statistics. 23 (5): ... The analysis of a nested case-control model must take into account the way in which controls are sampled from the cohort. ... Since the covariate is not measured for all participants, the nested case-control model is both less expensive than a full ...
David Cox (statistician)
An example of the use of the proportional hazards model is in survival analysis in medical research. The model can be used in ... The proportional hazards model, which is widely used in the analysis of survival data, was developed by him in 1972. ... the proportional hazards model and the Cox process, a point process named after him. He was a professor of statistics at ... "the development of the Proportional Hazard Regression Model." In 2010 he was awarded the Copley Medal of the Royal Society "for ...
Kaplan-Meier estimator
... parametric survival models and the Cox proportional hazards model may be useful to estimate covariate-adjusted survival. The ... Both are based on rewriting the survival function in terms of what is sometimes called hazard, or mortality rates. However, ... "sts - Generate, graph, list, and test the survivor and cumulative hazard functions" (PDF). Stata Manual. Cleves, Mario (2008). ... Kaplan-Meier estimator can be derived from maximum likelihood estimation of hazard function.[self-published source?] More ...
Flow sampling
These estimators range from fully parametric models such as the Mixed Proportional Hazard model, to nonparametric and ... Salant shows that heterogeneity in hazard rates between the stock and the flow distribution provides a key to understanding why ... Hausman, J. A. and T. Woutersen (2014), Estimating a semi-parametric duration model without specifying heterogeneity. Journal ...
Logrank test
The logrank statistic can be derived as the score test for the Cox proportional hazards model comparing two groups. It is ... assume the hazard functions in the two groups are proportional with hazard ratio λ {\displaystyle \lambda } and d 1 {\ ... If the hazard ratio is λ {\displaystyle \lambda } , there are n {\displaystyle n} total subjects, d {\displaystyle d} is the ... The logrank test statistic compares estimates of the hazard functions of the two groups at each observed event time. It is ...
Patricia Grambsch
Meller Grambsch is an American biostatistician known for her work on survival models including proportional hazards models. She ... With Terry M. Therneau, Grambsch is the author of the book Modeling Survival Data: Extending the Cox Model (Statistics for ... retrieved 2020-06-20 Reviews of Modeling Survival Data: Broström, Göran, zbMATH, Zbl 0958.62094{{citation}}: CS1 maint: ...
Poisson regression
... creates proportional hazards models, one class of survival analysis: see proportional hazards models for ... Other generalized linear models such as the negative binomial model or zero-inflated model may function better in these cases. ... A Poisson regression model is sometimes known as a log-linear model, especially when used to model contingency tables. Negative ... This model is popular because it models the Poisson heterogeneity with a gamma distribution. Poisson regression models are ...
Randomized controlled trial
Kaplan-Meier estimators and Cox proportional hazards models for time to coronary heart disease after receipt of hormone ... Vonesh, Edward F.; Chinchilli, Vernon G. (1997). "Crossover Experiments". Linear and Nonlinear Models for the Analysis of ...
Teaching-family model
Cox Proportional Hazards Regression Analysis as a Modeling Technique for Informing Program Improvement: Predicting Recidivism ... The Teaching-Family Model (TFM) is a model of care for persons in need of services and care necessary to support an improved ... The Teaching-Family Model has been suggested as a model program for residential treatment facility and behavior modification ... The model has been replicated over 800 times, although not all of the replications have proven effective and successful. This ...
Nancy Flournoy
Her work in this time on the graft-versus-tumor effect become "the first major application of the proportional hazards model ... for serving as a role model and mentor for graduate students and young faculty; for her scholarship in teaching and research, ...
Cyntha Struthers
... mathematical statistician whose research topics include missing data in longitudinal studies and proportional hazards models. ... "Role models needed for women students, says new prof", Update!, St. Jerome's College, vol. 5, no. 2, p. 7, Fall 1985, retrieved ...
Lasso (statistics)
... proportional hazards models, and M-estimators. Given the objective function 1 N ∑ i = 1 N f ( x i , y i , α , β ) {\ ... proportional hazards models, and M-estimators. Lasso's ability to perform subset selection relies on the form of the constraint ... lasso regularization is easily extended to other statistical models including generalized linear models, generalized estimating ... This can be modeled using the following regularization: ∑ i < j p , β i − β j , ≤ t 2 . {\displaystyle \sum _{i. < p < 1 {\ ...
Perfluorooctanoic acid
A proportional hazards regression model was used for each cancer type with the cancer as the outcome and PFOA serum level ... Office of Environmental Health Hazard Assessment, Cancer Toxicology and Epidemiology Section, Reproductive and Cancer Hazard ... Models were adjusted for time-varying- smoking and alcohol consumption, as well as sex, education and five-year birth cohort. ... hazard ratio = 1.10 and 1.34, respectively, for a 1-unit increase in log-transformed serum PFOA]. The study consisted of 32,254 ...
Cinnabar moth
An Analysis Based on the Proportional Hazards Model." Journal of Animal Ecology. 54 (3). Coombs, E. M., et al., Eds. (2004). ...
Formica polyctena
An Analysis Based on the Proportional Hazards Model."Journal of Animal Ecology, Vol. 54, No. 3 (Oct., 1985). Helantera, Heikki ... F. polyctena is consistent with this model, with almost completely sterile workers that do not lay eggs. This is in contrast to ... Aubert and Richard proposed this social vaccination model, where they argue that if fellow nestmates groom an infected ant, ...
Likelihood function
It is a key component of the proportional hazards model: using a restriction on the hazard function, the likelihood does not ... of a model, given an event, is the negative of the surprisal of the event, given the model: a model is supported by an event to ... That is, a model that does not meet these regularity conditions may or may not have a maximum likelihood estimator of the ... Due to the introduction of a probability structure on the parameter space or on the collection of models, it is possible that a ...
First-hitting-time model
Survival analysis Proportional hazards models Redner 2001 Bachelier 1900 Von E 1900 Smoluchowski 1915 Lundberg 1903 Tweedie ... Lee, M.-L. T.; Whitmore, G. A. (2010). "Threshold Proportional hazards and threshold regression: their theoretical and ... The model considers the event that the amount of money reaches 0, representing bankruptcy. The model can answer questions such ... In statistics, first-hitting-time models are a sub-class of survival models. The first hitting time, also called first passage ...
Compensation law of mortality
... proportional hazard models). The compensation law of mortality also represents a great challenge for many theories of aging and ... PMID 111909 Gavrilov, L.A. "A mathematical model of the aging of animals". Doklady Akademii Nauk SSSR, 1978, 238(2): 490-492. ...
Unobserved heterogeneity in duration models
McCall, B. P. (1994): Testing the Proportional Hazards Assumption in the Presence of Unmeasured Heterogeneity. Journal of ... and it enters the hazard function multiplicatively. One can define the conditional hazard as the hazard function conditional on ... It then follows that the average hazard is given by exp(x'β) αtα-1. More generally, it can be shown that as long as the hazard ... and the hazard function λ(.). Recent examples provide a nonparametric approaches to estimating the baseline hazard and the ...
Imperial examination
These features have been compared to similar aspects of the earlier Chinese model. In the British civil service, just as it was ... in numbers roughly proportional to each province's population. Elite individuals all over China, even in the disadvantaged ... over birth and allow for dramatic social mobility was most attractive for contemporary Europeans in the grip of the hazards of ... With the disappearance of the old aristocracy, Wu's system of bureaucrat recruitment once more became the dominant model in ...
False vacuum decay
The former tends as the cube of the bubble's radius while the latter is proportional to the square of its radius, so there is a ... Ellis, J.; Espinosa, J.R.; Giudice, G.F.; Hoecker, A.; Riotto, A. (2009). "The Probable Fate of the Standard Model". Phys. Lett ... Space hazards, Ultimate fate of the universe, Vacuum). ... Nonetheless, new physics beyond the Standard Model of Particle ... Salvio, Alberto (2015-04-09). "A Simple Motivated Completion of the Standard Model below the Planck Scale: Axions and Right- ...
Capacitor
The hazards posed by a capacitor are usually determined, foremost, by the amount of energy stored, which is the cause of things ... The simplest model of a capacitor consists of two thin parallel conductive plates each with an area of A {\displaystyle A} ... Thus the charge on the electrodes is equal to the integral of the current as well as proportional to the voltage, as discussed ... This model applies well to many practical capacitors which are constructed of metal sheets separated by a thin layer of ...
Impact event
Models developed in 2018 to explain the unusual spin of Uranus support a long-held theory that this was caused by an oblique ... Melosh, H. J. (2003). "Impact-generated tsunamis: An over-rated hazard". Lunar and Planetary Science Conference Abstract. 34: ... which is on average proportional to the diameter of the impactor. Asteroids with a 1 km (0.62 mi) diameter strike Earth every ... Computer modelling suggests that the impact involved large asteroids or protoplanets similar to the events believed to have led ...
Global Positioning System
AFGRL developed the Klobuchar model for computing ionospheric corrections to GPS location. Of note is work done by Australian ... the time delay between when the satellite transmits a signal and the ground station receives it is proportional to the distance ... GPS can be used to measure crustal motion and deformation to estimate seismic strain buildup for creating seismic hazard maps. ... longitude and height relative to an ellipsoidal Earth model. The height may then be further converted to height relative to the ...
Flood basalt
Cox, K. G. (1 November 1980). "A Model for Flood Basalt Vulcanism". Journal of Petrology. 21 (4): 629-650. doi:10.1093/ ... The lateral extent of a flood basalt flow is roughly proportional to the cube of the thickness of the flow near its source. ... Geological hazards, Future problems, Doomsday scenarios). ... "A new model for the emplacement of Columbia River basalts as ...
Deep diving
... has more hazards and greater risk than basic open water diving. Nitrogen narcosis, the "narks" or "rapture of the ... Using normal scuba equipment, breathing gas consumption is proportional to ambient pressure-so at 50 metres (160 ft), where the ... model, a two-stage regulator (patented by Novelli and Buggiani) equipped with a lung bag and soda lime filter for CO2 removal, ... Nitrogen narcosis becomes a hazard below 30 metres (98 ft) and hypoxic breathing gas is required below 60 metres (200 ft) to ...
Infrared
Light from a near-IR laser may thus appear dim red and can present a hazard since it may actually be quite bright. And even IR ... Jones, B.S.; Lynn, W.F.; Stone, M.O. (2001). "Thermal Modeling of Snake Infrared Reception: Evidence for Limited Detection ... 1879: Stefan-Boltzmann law formulated empirically that the power radiated by a blackbody is proportional to T4. 1880s and 1890s ... Thermal infrared radiation also has a maximum emission wavelength, which is inversely proportional to the absolute temperature ...
Linear no-threshold model
The LNT model is sometimes applied to other cancer hazards such as polychlorinated biphenyls in drinking water. The association ... response model in which the risk of inducing a cancer in an irradiated tissue by low doses of radiation is proportional to the ... The validity of the LNT model, however, is disputed, and three other significant models exist: the threshold model, which ... The LNT model has been contested by a number of scientists. It has been claimed that the early proponent of the model Hermann ...
Coaxial cable
With sufficient power, this could be a hazard to people near the cable. A properly placed and properly sized balun can prevent ... Coaxial cable is a particular kind of transmission line, so the circuit models developed for general transmission lines are ... The outer diameter is roughly inversely proportional to the cutoff frequency. A propagating surface-wave mode that only ... with the depth of penetration being proportional to the square root of the resistivity. This means that, in a shield of finite ...
Sweetened beverage
The food addiction model asserts that excessive consumption of palatable foods may be understood within the same ... Mishra, MB; Mishra, Shanu (2011-01-01). "Sugar-Sweetened Beverages: General and Oral Health Hazards in Children and Adolescents ... increase in sugar-sweetened beverage taxes would result in proportional reduction in consumption. Other solutions target ... model of overweight". Appetite. 114: 64-72. doi:10.1016/j.appet.2017.03.024. hdl:1983/699cf0f2-1344-4414-bd84-0cf80c0feff5. ...
Transmission system operator
Natural hazards and generation/consumption imbalances are a major cause of concern. To minimize the probability of grid ... System operations staff undertake this work using sophisticated energy modelling and communications systems. In addition to its ... They are financed either by the states or countries or by charging a toll proportional to the energy they carry. The system ...
Risk score
... as reverse-engineered by ProPublica using logistic regression and Cox's proportional hazard model. Hastie, T. J.; Tibshirani, R ... is estimated using a generalized linear model: E ( Y , X ) = P ( Y = 1 , X ) = g − 1 ( X β ) {\displaystyle {\begin{aligned}\ ... J. (1990). Generalized Additive Models. Chapman & Hall/CRC. ISBN 978-0-412-34390-2. Toren, Yizhar (2011). "Ordinal Risk-Group ...
Sabancaya
Rock fall would affect the area close to the summit domes, as would pyroclastic flows; these would be a further hazard to the ... and the proportional amount of fresh volcanic material increased at first; since 1997 discontinuous eruptions generate steam ... "Geomorphologic map and derived geomorphological evolution model of the Ampato volcanic complex (Southern Peru)". EGU General ... Annen, Catherine; Wagner, Jean-Jacques (2003-11-01). "The Impact of Volcanic Eruptions During the 1990s". Natural Hazards ...
Standard diving dress
Most of the hazards to which the standard diver was exposed are much the same as those to which any other surface supplied ... No-bolt model used similar rubber flange to 3-bolt helmets, but clamped between the bonnet and corselet which were connected at ... which was proportional to the depth at which the diver worked.[citation needed] Umbilical: A diver's umbilical is a cable made ... Later models were equipped with a diver's telephone for voice communications with the surface. The term deep sea diving was ...
Surface-supplied diving
A hazard is any agent or situation that poses a level of threat to life, health, property, or environment. Most hazards remain ... Some models require a bailout block to provide alternative breathing gas supply from the umbilical and bailout cylinder, but ... and the weight is directly proportional to the total volume - smaller helmets are lighter. To avoid fatigue, divers avoid ... or the combined probability of undesirable consequences of all the hazards of a specific activity. A hazard that is understood ...
Ultraviolet index
The UV index is designed as an open-ended linear scale, directly proportional to the intensity of UV radiation that causes ... Predictions are made by a computer model that accounts for the effects of sun-earth distance, solar zenith angle, total ozone ... Hazard scales). ... reports is usually a prediction based on a computer model. ...
Carbon monoxide detector
These advanced models cost somewhat more but are otherwise similar to the basic models. The digital models offer the advantage ... A biomimetic sensor works in a fashion similar to hemoglobin which darkens in the presence of CO proportional to the amount of ... They will warn the driver and passenger if there is a CO hazard. Another type is used by industrial hygienists and first ... Newer models are designed to signal a need to be replaced after a set time span. CO detectors all have "test" buttons like ...
Overfitting
For logistic regression or Cox proportional hazards models, there are a variety of rules of thumb (e.g. 5-9, 10 and 10-15 - the ... The book Model Selection and Model Averaging (2008) puts it this way. Given a data set, you can fit thousands of models at the ... An under-fitted model is a model where some parameters or terms that would appear in a correctly specified model are missing. ... Model Selection and Model Averaging, Cambridge University Press. Harrell, F. E. Jr. (2001), Regression Modeling Strategies, ...
Water security
There is no unifying theory or model for determining or managing water risk.: 13 Instead, a range of theories, models, and ... Water security risks in Bangladesh include:: 45 some natural hazards that related to climate (climate hazards) the impacts of ... 140 Water scarcity and water security do not have to be directly proportional: There are regions with high water security, ... For example, the long rains in East Africa which fall March to May have been difficult to simulate within the climate models ...
Arcade game
In Drive Mobile, a steering wheel was used to control a model car over a road painted on a metal drum, with the goal being to ... The gameplay itself can be of any arcade game, and the number of tickets received are proportional to the player's score. Skee ... Cabot, Anthony N.; Light, Glenn J.; Rutledge, Karl F. (2009). "Alex Rodriguez, a Monkey, and the Game of Scrabble: The Hazard ... with later arcade systems such as the Sega Model 3 remaining considerably more advanced than home systems through the late ...
Testing cosmetics on animals
doi:10.1016/s0262-4079(07)61866-1. Mone, Gregory (April 2014). "New Models in Cosmetics Replacing Animal Testing". ... the acceptability of this to opponents of testing is inversely proportional to how recent the data is. Methods of testing ... repeated oral force-feeding studies lasting weeks or months to look for signs of general illness or specific health hazards, ... research companies such as NOTOX have developed a synthetic model of the human liver, which is the main organ to detox the body ...
Static electricity
For modelling the effect of static discharge on sensitive electronic devices, a human being is represented as a capacitor of ... As little as 0.2 millijoules may present an ignition hazard; such low spark energy is often below the threshold of human visual ... and can be roughly proportional to particulate flow. Dust clouds of finely powdered substances can become combustible or ... This is not considered to be a hazard for dust clouds. Propagating brush discharge is high in energy and dangerous. Occurs when ...
Glossary of underwater diving terminology: P-S
red tide reduced gradient bubble model A computationally intensive bubble model decompression algorithm developed by Bruce ... pressure transducer A component that produces a signal proportional to a pressure input, which can be processed to give an ... element Item of equipment or process with the purpose to prevent or limit the consequences of a high risk hazard, that if ... perfusion limited The assumption in a decompression model that perfusion has the dominant influence on gas uptake and release. ...
Buoyancy compensator (diving)
One of these later models was the Seatec Manta, with shoulder buckles and a softpac structure (without a rigid backpack) In ... The buoyancy compensator is both an important safety device when used correctly, and a significant hazard when misused or ... The depth range in which effectively stable neutral buoyancy can be maintained is inversely proportional to the volume of ... Most BCs do not have a CO2 inflation option, which eliminates this hazard. Redundant bladders may be inadvertently filled, ...
Sea
... so global climate modelling makes use of ocean circulation models as well as models of other major components such as the ... Homer describes the ten-year voyage of the Greek hero Odysseus who struggles to return home across the sea's many hazards after ... radiating outwards at a velocity proportional to the square root of the depth of the water and which therefore travels much ... Ocean models make use of a branch of physics, geophysical fluid dynamics, that describes the large-scale flow of fluids such as ...
Earthquake casualty estimation
A model of a city in which each district has its own distribution of buildings into classes and its population, is far superior ... This is so because the surface wave M, which is quickly obtained, is defined as proportional to the 20 sec Reighly surface wave ... Such calculations are similar to those made to assess the seismic hazard, part of the field of engineering seismology. Errors ... A cost-effective way to model a large city is to treat each administrative district as a separate settlement. In many large ...
Erodability
An alternative model for bedrock erosion is the unit stream power, which assumes that erosion rates are proportional to the ... Natural Hazards and Earth System Sciences. 15: 225-245. doi:10.5194/nhess-15-225-2015. ISSN 1561-8633. Poesen, Jean; Lavee, ... The most commonly used model for predicting soil loss from water erosion is the Universal Soil Loss Equation (USLE) (also known ... Bosco, Claudio; de Rigo, Daniele; Dewitte, Olivier; Poesen, Jean; Panagos, Panos (2015). "Modelling soil erosion at European ...
Data generation for the Cox proportional hazards model with time-dependent covariates: A method for medical researchers - LSE...
The Cox proportional hazards model is one such method that is widely used. As more extensions of the Cox model with time- ... Hendry, David J. (2013) Data generation for the Cox proportional hazards model with time-dependent covariates: A method for ... This paper develops a method for the generation of survival times that follow a Cox proportional hazards model with time- ... Data generation for the Cox proportional hazards model with time-dependent covariates: A method for medical researchers ...
The increasingly mixed proportional hazard model: An application to socioeconomic status, health shocks, and mortality<...
... model. We compare and contrast this model with the mixed proportional hazard (MPH) model, which continues to be the workhorse ... model. We compare and contrast this model with the mixed proportional hazard (MPH) model, which continues to be the workhorse ... model. We compare and contrast this model with the mixed proportional hazard (MPH) model, which continues to be the workhorse ... model. We compare and contrast this model with the mixed proportional hazard (MPH) model, which continues to be the workhorse ...
Importance of events per independent variable in proportional hazards regression analysis. II. Accuracy and precision of...
... in a proportional hazards regression analysis was evaluated using Monte Carlo simulation techniques for data from a randomized ... large sample properties did not hold for variance estimates from the proportional hazards model, and the Z statistics used to ... the results of proportional hazards regression analyses should be interpreted with caution because the statistical model may ... The analytical effect of the number of events per variable (EPV) in a proportional hazards regression analysis was evaluated ...
IMSEAR at SEARO: Survival analysis: Cox proportional hazards model.
Internet Scientific Publications
Results: Cox Proportional Hazards Model. Finally, I generated a Cox Proportional Hazards Model to further look at the second ... In relation to the second hypothesis, the Cox Proportional Hazards Model in Table 3 (net all control variables) shows that, in ... In relation to the third hypothesis, the Cox Proportional Hazards Model in Table 3 (net all control variables), shows that an ... Relate results in the Cox Proportional Hazards model will be discussed further in that section. These results support the ...
Crystalline silica exposure and lung cancer mortality in diatomaceous earth industry workers: a quantitative risk assessment |...
Coxs proportional hazards model. The Coxs proportional hazards model was used as an alternative method for evaluating ... Results from the Coxs proportional hazards models were similar to the results of Poisson regression models. For example, the ... Proportional hazards models were fitted with the SAS procedure PHREG10 configured for a matched logistic regression analysis ... POISSON REGRESSION ANALYSES AND COXS PROPORTIONAL HAZARDS MODEL. Table 1 and figure 1 show the results of fitting the Poisson ...
Organ Transplantation With COVID-19-Positive Deceased Donors
NIOSHTIC-2 Search Results - Full View
Application of hazard analysis and critical control point system in the dairy industry
Proportional Hazards Models. EN. dc.subject. Quality Control. EN. dc.subject. Risk Assessment. EN. ... Application of hazard analysis and critical control point system in the dairy industry. dc.contributor.author. Kassem, M.. ... Application of hazard analysis and critical control point system in the dairy industry. EN. ... and dairy products before and after application of a hazard analysis and critical control point [HACCP] system at a milk and ...
Prediction of resistance to chemotherapy in ovarian cancer: a systematic review | BMC Cancer | Full Text
Modelling techniques varied, the most popular being Cox proportional hazards regression and hierarchical clustering which were ... Research into a predictive, as opposed to prognostic, model could be highly beneficial and aid the identification of the most ... 42 studies were identified and both the data collection and modelling methods were compared. The majority of studies utilised ... Cox proportional hazards models. When studies identified by this review applied the Cox proportional hazards model to predict ...
Application of random survival forests in understanding the determinants of under-five child mortality in Uganda in the...
The Cox proportional hazards model has been a common choice in analysing data to understand factors strongly associated with ... Random survival forests and the Cox proportional hazards model agree that the sex of the household head, sex of the child, ... However, due to its restrictive proportional hazards (PH) assumption, some covariates of interest which do not satisfy the ... Thus the first part of the analysis is based on the use of the classical Cox PH model and the second part of the analysis is ...
Frontiers | Long-Term Use of Statins Lowering the Risk of Rehospitalization Caused by Ischemic Stroke Among Middle-Aged...
... hazard ratio, HR = 1.29-1.39, p , 0.05). Rosuvastatin was the most preferred lipid-lowering medicine with lower HRs of reHospIS ... and characteristics of the first hospitalization due to IS were all adjusted in models. Moreover, increasing trends of HRs of ... hazard ratio, HR = 1.29-1.39, p , 0.05). Rosuvastatin was the most preferred lipid-lowering medicine with lower HRs of reHospIS ... and characteristics of first hospitalization due to IS were all adjusted in models. Moreover, increasing trends of HRs of ...
Extracorporeal versus conventional cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: a secondary...
In this secondary analysis, the effect of ECPR on 180-day survival using Kaplan-Meier estimates and Cox proportional hazard ... model was examined. Among 256 patients (median age 58 years, 83% male) with median duration of resuscitation 52.5 min ... Cox proportional hazards model of 180-day survival. After adjusting for the most important covariates in the Cox proportional ... Table 3 The Cox proportional hazards model for 180-day mortality. Full size table. ...
HERG1A potassium channel is the predominant isoform in head and neck squamous cell carcinomas: evidence for regulation by...
Individual social capital and survival: a population study with 5-year follow-up | BMC Public Health | Full Text
Analyses were performed with Cox proportional hazard models by which hazard ratios and 95% confidence intervals were calculated ... The statistical analyses were performed using the Cox proportional hazard models for the estimation of hazard ratio (HR) and 95 ... Analyses were performed with Cox proportional hazard models by which hazard ratios and 95% confidence intervals were calculated ... Model A shows the estimates adjusted for age and gender while Model B further adjusts for socioeconomic status (education, ...
Risk of lung cancer associated with quantitative beryllium exposure metrics within an occupational cohort | Occupational &...
Evaluating bias from birth cohort effects in the age-based Cox proportional hazards model. Epidemiology 2011;22:249-56. ... Initial analyses using continuous exposure-response models were based on power models (ie, log-linear models using a log- ... are identical to those from Cox proportional hazards regression. Hazard ratios (HRs) for lung cancer mortality were estimated ... Final models were checked for proportionality of hazards with age by evaluating its product with each exposure metric as an ...
Preterm birth and risk of type 1 and type 2 diabetes: a national cohort study | SpringerLink
Grambsch PM (1995) Goodness-of-fit and diagnostics for proportional hazards regression models. Cancer Treat Res 75:95-112 ... The proportional hazards assumption was assessed by examining log-log plots [29], and was met in each model. ... Cox proportional hazards regression was used to compute HRs and 95% CIs for associations between gestational age at birth and ... In the stratified Cox model, each set of siblings had its own baseline hazard function that reflects the familys shared ...
PUB HLTH 7104 - Biostatistics | Course Outlines
Assessing the assumptions of Cox proportional hazards regression models. Practical: Stratified Cox proportional hazards models ... Lecture: Introduction to Cox proportional hazards regression models. Practical: Fitting a Cox model in Stata. ... Practical: Fitting a multiple linear regression model. Linear Models 3. Lecture: Analysis of covariance and model assumptions. ... Generalized Linear Models. Lecture: Introduction to common Generalized Linear Models. Practical: Poisson regression and glm. ...
Potential Survival Benefit of Anti-Apoptosis Protein: Survivin-Derived Peptide Vaccine with and without Interferon Alpha...
... and differences between two groups were compared using the log-rank test and Cox proportional hazards regression models. A ... Table 5 lists the results of proportional hazards regression analysis used to test the predictive value of each variable for OS ... In this multivariate model adjusted for age, ECOG PS, and the presence of visceral metastases, vaccination therapy was an ... "Dendritic cell immunotherapy combined with gemcitabine chemotherapy enhances survival in a murine model of pancreatic carcinoma ...
Cost-effectiveness of diacetylmorphine versus methadone for chronic opioid dependence refractory to treatment | CMAJ
Proportional hazards frailty models for recurrent methadone maintenance treatment. Am J Epidemiol 2009;170:783-92. ... Model design. We developed a decision-analytical model to capture the cycles of treatment, relapse and abstinence observed in ... Dynamics of the cohort model. All patients entered the model in a treatment state (diacetylmorphine or methadone maintenance ... we derived model parameters from the trial data where possible. When trial data were not available to populate model parameters ...
SAS Training in Finland -- Find a Course
Survival Analysis Using the Proportional Hazards Model 3 Intermediate. Advanced Statistical Modeling Using the NLMIXED ... Managing Models in SAS Viya 3 Intermediate. Managing SAS Analytical Models Using SAS Model Manager Version 14.2 3 Intermediate ... Credit Risk Modeling 3 Intermediate. Risk Modeling Add-on for SAS Visual Machine Learning: Using Credit Scoring Nodes 3 ... Predictive Modeling Using Logistic Regression 4 Expert. Predictive Modeling Using SAS High-Performance Analytics Procedures 4 ...
Courses - Arnold School of Public Health | University of South Carolina
... variables and the proportional hazards model. BIOS 765 Research Design in the Biomedical Sciences. (3) (Prereq: BIOS 757) ( ... frailty model, competing risk model and multi-state model. Techniques motivated by applications in epidemiology and clinical ... Encompasses logistic and other binary regressions, log-linear models, and gamma regression models. ... BIOS 815 Generalized Linear Models [=STAT 775] (3) (Prereq: STAT 713 or STAT 513, and STAT 705 or BIOS 757. Statistical theory ...
Time to Colonoscopy After Positive Fecal Blood Test in Four U.S. Health Care Systems | RAND
Miki Horiguchi, Ph.D. | Harvard Catalyst Profiles | Harvard Catalyst
Etudes spécifiques pays-régions sur le Nutri-Score - Ministère de la Santé et de la Prévention
Multivariable-adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals ( ... Multi-adjusted Cox proportional hazards models were computed. A higher FSAm-NPS DI score, reflecting a lower nutritional ... model in the Bulgarian context, with the potential to help consumers better understand the nutritional quality of. food. The ... regression models within and across food categories were fit.. Results : Compared with the Reference Intakes group, ...
Haploidentical Versus Matched Sibling Donor Hematopoietic St... : HemaSphere
A proportional hazards model for sub distribution of a competing risk. J Am Stat Assoc. 1999; 94:496-509.. * Cited Here , ... 22 Multivariate analysis was performed using a Cox proportional-hazards model which included variables differing significantly ... Results were expressed as the hazard ratio (HR) with a 95% confidence interval (95% CI). All tests were 2-sided with a type 1 ... hazard ratio [HR] = 0.56; P = 0.14), respectively. By multivariate analysis, relapse incidence, and leukemia-free survival were ...
Survival example | Stata
Here we will focus on the Cox proportional hazards model using a model fitted on our dose-age data that we described above: . ... and gamma models. In the case of the Cox proportional hazards model, ... The robust inference of the Cox proportional hazards model. Journal of the American Statistical Association 84: 1074-1078. ... baseline hazard (and stratified baseline hazard if estimates are stratified) *cumulative baseline hazard *baseline survivor ...
Transferrin Saturation, Dietary Iron Intake, and Risk of Cancer | Annals of Family Medicine
Schoenfeld D. Partial residuals for the proportional hazards model. Biometrika. 1982;69:51-55. ... Without adjustments, the Cox proportional hazards model analysis indicates that increased serum transferrin saturation did not ... We performed Cox proportional hazards analysis with cancer event time for each group, controlling for age, sex, race, smoking ... The results of the Schoenfeld analysis indicated that the hazards were proportional. No significant interaction was found in ...
Assessed using Cox proportional hazards regrRatioMultivariable Cox proportionalCovariatesRatios and 95AnalysesEstimatesOutcomesResultsKaplan-MeierUnivariatePredictionMortalityParametricEstimateEstimationStatisticalPoissonPredictorsCohortHealth hazardsAssumptionSpatialPredictiveHeterogeneityDurationMETHODSHistologyDerived a Cox regression modelExposuresPrognosticCategoricalStrokeDataRiskMedian ageDependencePercentageStudyReductionEvaluationsTimeVariableEmpirical evidenceDiabetes
Assessed using Cox proportional hazards regr1
- The risk of reHospIS was assessed using Cox proportional hazards regression model. (frontiersin.org)
Ratio5
- After adjusting for sex, age and frailty, in-hospital mortality did not significantly differ between transplant and dialysis patients [hazard ratio (HR) 0.81, 95% CI 0.59-1.10, P = 0.18]. (medscape.com)
- We compare hazard ratio estimates for effect of an aggressive treatment regimen from Cox proportional hazards models using time to initial treatment outcome, predicted vital status, and true vital status at the end of the cohort period. (cdc.gov)
- A study by Moss et al found that in patients with KCNQ1 mutations, the Cox proportional hazards survivorship model indicated an increased risk for cardiac events in patients with transmembrane versus C-terminus mutations (hazard ratio, 2.06), as well as in patients with mutations resulting in dominant-negative versus haploinsufficiency ion channel effects (hazard ratio, 2.26). (medscape.com)
- Cox regression model was used to calculate the hazard ratio (HR).A count of 314 cases (3.4%) of hypoparathyroidism was identified. (elsevier.com)
- Further multivariable analysis revealed a proportional hazard ratio (HR) for disease-free survival rate of 1.87 (95% CI: 1.04-3.37 pâ ¯=â ¯0.036). (bvsalud.org)
Multivariable Cox proportional2
- Groups were compared through a multivariable Cox proportional Hazards model. (ices.on.ca)
- Prediction models were developed in UKB using multivariable Cox proportional hazards regression for circulatory mortality, incident stroke and MI, and externally validated in EPIC-Norfolk. (ucl.ac.uk)
Covariates8
- As more extensions of the Cox model with time-dependent covariates are developed, simulations studies will grow in importance as well. (lse.ac.uk)
- This paper develops a method for the generation of survival times that follow a Cox proportional hazards model with time-dependent covariates. (lse.ac.uk)
- However, due to its restrictive proportional hazards (PH) assumption, some covariates of interest which do not satisfy the assumption are often excluded in the analysis to avoid mis-specifying the model. (biomedcentral.com)
- Thus the first part of the analysis is based on the use of the classical Cox PH model and the second part of the analysis is based on the use of random survival forests in the presence of covariates that do not necessarily satisfy the PH assumption. (biomedcentral.com)
- Random survival forests and the Cox proportional hazards model agree that the sex of the household head, sex of the child, number of births in the past 1 year are strongly associated to under-five child mortality in Uganda given all the three covariates satisfy the PH assumption. (biomedcentral.com)
- Random survival forests are appealing methods in analysing public health data to understand factors strongly associated with under-five child mortality rates especially in the presence of covariates that violate the proportional hazards assumption. (biomedcentral.com)
- Analysis of the Proportional Hazards Model with Sparse Longitudinal Covariates. (unc.edu)
- Time-varying Cox proportional hazard regression models were used to estimate hazard ratios (HRs) for all-cause and cause-specific CVDs associated with PM2.5, adjusting for conventional covariates. (ox.ac.uk)
Ratios and 952
- Analyses were performed with Cox proportional hazard models by which hazard ratios and 95% confidence intervals were calculated. (biomedcentral.com)
- Hazard ratios and 95% confidence intervals for associations with 10-year breast cancer-specific survival were estimated in Cox proportional-hazard models. (elsevier.com)
Analyses4
- Below this value for EPV, the results of proportional hazards regression analyses should be interpreted with caution because the statistical model may not be valid. (nih.gov)
- Methods The authors conducted Cox proportional hazards regression analyses of lung cancer risk with cumulative, mean and maximum 'daily weighted average' (DWA) exposure among 5436 workers, using age-based risk sets. (bmj.com)
- Cox proportional hazards models, univariate and multivariate analyses were used to identify predictors of local failure. (oldcitypublishing.com)
- Univariate analyses were conducted using proportional hazards models. (emmes.com)
Estimates7
- large sample properties did not hold for variance estimates from the proportional hazards model, and the Z statistics used to test the significance of the regression coefficients lost validity under the null hypothesis. (nih.gov)
- In this secondary analysis, the effect of ECPR on 180-day survival using Kaplan-Meier estimates and Cox proportional hazard model was examined. (biomedcentral.com)
- Cox models yielded estimates of adjusted hazard ratios, with categorical variables for lagged cumulative exposure to 3 types of MWF (straight, soluble, and synthetic). (cdc.gov)
- For exponential and Weibull models, estimates are available in either the accelerated-time or hazard metric. (stata.com)
- This may violate the non-informative censoring assumption of the model and may produce biased effect estimates. (cdc.gov)
- Models utilizing the predicted vital status produce effect estimates consistently stronger and closer to the true treatment effect than estimates produced by models using the initial treatment outcome. (cdc.gov)
- Conclusions: Although studies often use initial treatment outcomes to estimate treatment effects, this may violate the non-informative censoring assumption of the Cox proportional hazards model and result in biased treatment effect estimates. (cdc.gov)
Outcomes4
- We introduce a duration model that allows for unobserved cumulative individual-specific shocks, which are likely to be important in explaining variations in duration outcomes, such as length of life and time spent unemployed. (monash.edu)
- Methods: We derive and apply a logistic regression model to predict vital status at the end of the cohort period and modify the unobserved survival outcomes to better match the predicted survival experience of study subjects. (cdc.gov)
- Cox proportional hazards models were fitted to evaluate the relationship between kidney function and vascular outcomes. (nyu.edu)
- We explored the association between complete and proportional ABCDEF bundle performance and three sets of outcomes: patient-related (mortality, ICU and hospital discharge), symptom-related (mechanical ventilation, coma, delirium, pain, restraint use), and system-related (ICU readmission, discharge destination). (anesthesiaexperts.com)
Results4
- Validity is assessed in a set of simulation experiments and results indicate that the proposed procedure performs well in producing data that conform to the assumptions of the Cox proportional hazards model. (lse.ac.uk)
- Exposure-response patterns were consistent with prior reports from this cohort, and results for splined exposures generally reflected their categorically modeled counterparts. (cdc.gov)
- Prognostic model for survival in patients with metastatic renal cell carcinoma: results from the international kidney cancer working group. (emmes.com)
- Multiple datasets are created, models run, and results pooled so conclusions can be drawn. (datasurg.net)
Kaplan-Meier1
- Kaplan-Meier estimator and Cox proportional hazard model were used to assess the association with predictors. (bvsalud.org)
Univariate1
- Suppose there is a series of observations from a univariate distribution and we want to estimate the mean of that distribution (the so-called location model ). (wikipedia.org)
Prediction4
- Quasi maximum likelihood estimation and prediction in the compound Poisson ECOGARCH(1,1) model. (uni-muenchen.de)
- Modeling dependencies between rating categories and their effects on prediction in a credit risk portfolio. (uni-muenchen.de)
- Prediction models for circulatory mortality in men and women had optimism adjusted C-statistics and R2 statistics between 0.75-0.77 and 0.33-0.44, respectively. (ucl.ac.uk)
- This model showed acceptable discrimination and good calibration for risk prediction of chronic cardio-metabolic disorders in short and long-term follow-up in the Iranian population. (biomedcentral.com)
Mortality10
- We apply the IMPH model to study the relationships among socioeconomic status, health shocks, and mortality, using 19 waves of data drawn from the German Socio-Economic Panel (SOEP). (monash.edu)
- OBJECTIVE To use various exposure-response models to estimate the risk of mortality from lung cancer due to occupational exposure to respirable crystalline silica dust. (bmj.com)
- METHODS Data from a cohort mortality study of 2342 white male California diatomaceous earth mining and processing workers exposed to crystalline silica dust (mainly cristobalite) were reanalyzed with Poisson regression and Cox's proportional hazards models. (bmj.com)
- For those who died of lung cancer the linear relative rate model predicted rate ratios for mortality from lung cancer of about 1.6 for the mean cumulative exposure to respirable silica compared with no exposure. (bmj.com)
- Cox analysis revealed that TB-related mortality hazard ratios included treatment default (8.9), multidrug resistance (5.7), recently transmitted TB (4.1), weight loss (3.9), and hav- ing less than 6 years of formal education (2). (cdc.gov)
- The Cox proportional hazards model has been a common choice in analysing data to understand factors strongly associated with high child mortality rates taking age as the time-to-event variable. (biomedcentral.com)
- The hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality were estimated using a Cox regression model. (jpmph.org)
- Cox proportional hazard logistic regression models were estimated to determine the association between religious service attendance and mortality. (elsevier.com)
- Participants with the most frequent religious service attendance had a 47% reduction of all-cause mortality risk compared their peer who did not attend religious services at all (HR 0.53, CI 0.35-0.79) in the fully adjusted model including socioeconomic status, non-cardiovascular medical conditions, health behaviors, social support and allostatic load. (elsevier.com)
- Cox proportional hazard models with age at study entry as the time scale were used to investigate the relationship between DIS diagnoses and mortality, adjusted for participant education, smoking and obesity at baseline. (cambridge.org)
Parametric2
Estimate4
- The authors used Cox proportional hazards regression models to estimate relative risks and 95% confidence intervals. (medscape.com)
- Because the shear wave velocity reduction is proportional to the percentage of serpentines in the mantle, we can use velocity reduction to estimate the degree of serpentinisation, and therefore, the amount of water that has been released from the subducted slab," said Assistant Professor Ping Tong, a Principal Investigator at EOS who co-authored the study. (earthobservatory.sg)
- combining extensive sea and land surface temperature reconstructions from the Last Glacial Maximum with climate model simulations we estimate a lower median (2.3 K) and reduced uncertainty (1.7-2.6 K 66% probability). (skepticalscience.com)
- The model estimate of the cooling during the Last Glacial Maximum is a clear underestimate. (skepticalscience.com)
Estimation2
- This paper develops a new semiparametric approach for the estimation of hazard functions in the presence of unobserved heterogeneity. (cambridge.org)
- Partial likelihood estimation of isotonic proportional hazards models. (unc.edu)
Statistical1
- Statistical models used in survival analysis that assert that the effect of the study factors on the hazard rate in the study population is multiplicative and does not change over time. (bvsalud.org)
Poisson3
- 0.05) in nearly all of the models evaluated and the linear relative rate model with a 10 year exposure lag seemed to give the best fit in the Poisson regression analysis. (bmj.com)
- Zero-inflated generalized Poisson models with regression effects on the mean, dispersion and zero-inflation level applied to patent outsourcing rates. (uni-muenchen.de)
- A geoadditive Bayesian latent variable model for Poisson indicators. (uni-muenchen.de)
Predictors1
- Multivariable analysis using a log-logistic model stratified by center and multivariable fractional polynomials was conducted to identify independent predictors of survival. (emmes.com)
Cohort2
- We constructed a semi-Markov cohort model using data from the North American Opiate Medication Initiative trial, supplemented with administrative data for the province of British Columbia and other published data, to capture the chronic, recurrent nature of opioid dependence. (cmaj.ca)
- For incident stroke and MI, addition of RV to FRS did not improve model performance in either cohort. (ucl.ac.uk)
Health hazards2
- Although the non-malignant respiratory health hazards of occupational exposure to dust have been known for centuries, the possibility of an association of occupational exposure to respirable crystalline silica dust with lung cancer has been debated in the scientific literature in recent decades. (bmj.com)
- EPID 747 Environmental Epidemiology (3) (Prereq: EPID 700, BIOS 700) (spring of every even year) Emphasis on the epidemiology of selected environmental factors which may affect human health including the identification of health hazards and methods of investigation. (sc.edu)
Assumption2
- Survival trees and random survival forests are increasingly becoming popular in analysing survival data particularly in the case of large survey data and could be attractive alternatives to models with the restrictive PH assumption. (biomedcentral.com)
- Additional y, most specimens were col ected shared frailty model, which is an extension of the Cox from cases in Cebu province, including from the independ- proportional hazards model that accounts for clustering, ent cities of Cebu City, Lapu-Lapu City and Mandaue City and the proportional hazards assumption was checked (191 [60.3%] of specimens overall and 48/68 [70.6%] using Schoenfeld residuals. (who.int)
Spatial2
- Modelling count data with overdispersion and spatial effects. (uni-muenchen.de)
- Annual PM2.5 concentrations were estimated using a satellite-based model with national coverage and 1 x 1 km spatial resolution. (ox.ac.uk)
Predictive2
- Research into a predictive, as opposed to prognostic, model could be highly beneficial and aid the identification of the most suitable treatment for patients. (biomedcentral.com)
- A nonparametric predictive alternative to the Imprecise Dirichlet Model: the case of a known number of categories. (uni-muenchen.de)
Heterogeneity2
- The hazard function is specified parametrically, whereas the distribution of the unobserved heterogeneity is indirectly estimated using the method of kernels. (cambridge.org)
- This paper applies discrete-time proportional hazards models with unobserved heterogeneity for several worker skill measures and human capital accumulation, interacted with firm-size categories and industry knowledge-intensity to ascertain how knowledge-skill complementarities are influenced by firm size. (pej.pt)
Duration2
- We compare and contrast this model with the mixed proportional hazard (MPH) model, which continues to be the workhorse of applied single-spell duration analysis in economics and the other social sciences. (monash.edu)
- Dependence Measures in Bivariate Gamma Frailty Models * Bivariate duration data frequently arise in economics, biostatistics and other areas. (ijournalpapers.icu)
METHODS2
- 42 studies were identified and both the data collection and modelling methods were compared. (biomedcentral.com)
- One of most popular methods for survival analysis is Cox proportional hazards regression. (biomedcentral.com)
Histology1
- 9 ] investigated the survival of patients following paclitaxel and platinum chemotherapy and found histology to be a significant predictor of overall survival in multivariate Cox proportional hazards regression. (biomedcentral.com)
Derived a Cox regression model1
- We derived a Cox regression model comparing differences in time to TB diagnosis after US entry among 19 birth regions, adjusting for sex, birth year, and age at entry. (cdc.gov)
Exposures1
- Relating in vitro to in vivo exposures with physiologically-based tissue dosimetry and tissue response models. (cdc.gov)
Prognostic4
- The present study aimed to construct a model based on pyroptosis-related long-stranded non-coding RNA (lncRNA) to evaluate the potential prognostic application in bladder cancer. (portlandpress.com)
- Therefore, we aimed to investigate the role of prognostic factors on breast cancer survival using Additive Empirical Bayesian model with large data set. (who.int)
- Nine clinical factors can be used to model survival in mRCC and form distinct prognostic groups. (emmes.com)
- 0.001] were prognostic in univariable models. (elsevier.com)
Categorical1
- The best-fitting models were generally categorical or piecewise log-linear, with the steepest increase in lung cancer risk between 0 and 10 μg/m 3 for both mean and maximum DWA exposure and between 0 and 200 μg/m 3 -days for cumulative DWA exposure. (bmj.com)
Stroke1
- Performance of Framingham risk scores (FRS) for incident stroke and incident MI, with addition of RV to FRS, were compared with a simpler model based on RV, age, smoking status and medical history (antihypertensive/cholesterol lowering medication, diabetes, prevalent stroke/MI). (ucl.ac.uk)
Data10
- An essential starting point for simulation studies of time-to-event models is the ability to produce simulated survival times from a known data generating process. (lse.ac.uk)
- The IMPH model is found to fit the data statistically better than the MPH model, and unobserved health shocks and socioeconomic status are shown to play powerful roles in predicting longevity. (monash.edu)
- Data were analyzed using Cox proportional hazards regression models. (greenmedinfo.com)
- When using Cox proportional hazards models to analyze these cohorts, this leads to censoring subjects at the time of the initial treatment outcome, instead of them providing full survival data. (cdc.gov)
- The model was validated using an independent data set of 645 patients treated with tyrosine kinase inhibitor (TKI) therapy. (emmes.com)
- The experimental data indicate that the CDW consists on an alternating Star of David and trihexagonal distortions and its dynamics goes beyond the classical weak-coupling scenario and is discussed within strong-electron phonon coupling and non-adiabatic models. (bvsalud.org)
- Such an approach willCited by: Concerning bivariate least squares linear regression, the classical re-sults obtained for extreme structural models in earlier attempts [18] [11] are reviewed using a new formalism in terms of deviation (matrix) traces which, for homoscedastic data, reduce to usual quantities leaving aside an unessential (but dimensional) multiplicative factor. (ijournalpapers.icu)
- Moreover, adding data of educational levels and marital status did not improve, the discrimination and calibration in the enhanced model. (biomedcentral.com)
- Because seismic noise occurs all the time and from a variety of locations, we had a wealth of data to construct a high-resolution 3D shear wave velocity model of Myanmar," said Dr Shucheng Wu, a Research Fellow at EOS and the lead author of the study. (earthobservatory.sg)
- For example, the study uses a relatively new global mean surface temperature reconstruction for the LGM of just 2.2°C cooler than interglacial temperatures in the locations where they have proxy data, or 2.6°C from the global model average. (skepticalscience.com)
Risk5
- In this model, two key work characteristics-(1) one's job demands and (2) the level of one's decision latitude-combine to determine the risk of psychological strain and physical illness. (ispub.com)
- The estimated mean DWA beryllium exposure associated with 10 −3 excess lifetime risk based on the piecewise log-linear model is 0.033 μg/m 3 . (bmj.com)
- Subdistribution hazards models to evaluate the outcome risk with non-CVD death treated as a competing event. (ajkd.org)
- In a multivariable model, the highest cancer risk was calculated among nonpersistent statin users. (cdc.gov)
- The present study used proportional hazards models with the General Social Survey, Cycles 20 and 21, to assess the impact of providing care to a partner, a parent or parent-in-law, another relative, or a non-relative on the risk of leaving employment. (open.ac.uk)
Median age1
- The median age of all cases models were adjusted for morbidity, week of specimen was 33 years (interquartile range [IQR]: 21-46), and 142 col ection of first positive test, age, sex and province. (who.int)
Dependence2
- In normal distribution models, we are familiar with using the ordinary product moment correlation (Pearson correlation) for measuring the dependence between the various : Philip Hougaard. (ijournalpapers.icu)
- In "bivariate frailty models", dependence between the frailties (i.e., unobserved determinants) induces dependence between the durations. (ijournalpapers.icu)
Percentage1
- INTERVENTIONS We defined ABCDEF bundle performance (our main exposure) in two ways: 1) complete performance (patient received every eligible bundle element on any given day) and 2) proportional performance (percentage of eligible bundle elements performed on any given day). (anesthesiaexperts.com)
Study4
- This study aimed to assess the hygiene quality of some packaged milk [pasteurized or sterilized] and dairy products before and after application of a hazard analysis and critical control point [HACCP] system at a milk and dairy products company in Cairo, Egypt. (who.int)
- His Meningioma study combines topics from a wide range of disciplines, such as Transcriptome, Local failure and Proportional hazards model. (research.com)
- For external validation of the model in the Tehran lipids and glucose study (TLGS), the Area under the curve (AUC) and the Hosmer-Lemeshow (HL) goodness of fit test were performed for discrimination and calibration, respectively. (biomedcentral.com)
- Another concern regarding the study is in the model they used - the University of Victoria (UVic) climate model. (skepticalscience.com)
Reduction1
- Early detection of musculoskeletal disorders in the workplace if followed by appropriate preventive interventions like hazard reduction, modified work, recovery time, task rotation or other measures can serve as tools for primary prevention. (cdc.gov)
Evaluations1
- Evaluations of the fit of the models were performed by comparing their deviances. (bmj.com)
Time2
- Cody, I have tried the survreg() in the Design library, it is analogous to survreg() in the survival library and it seems to me it is designed only for accelerated time models like the accelerated failure model (or accelerated lifetime model) and not for proportional hazard models. (ethz.ch)
- Her main research lines include the analysis of time series, models for load forecasting (long, medium and short term), machine learning and clustering, which are key techniques to develop suitable Demand Response programs. (upct.es)
Variable2
- Importance of events per independent variable in proportional hazards regression analysis. (nih.gov)
- A Bayesian semiparametric latent variable model for mixed responses. (uni-muenchen.de)
Empirical evidence2
- However, despite the wide use of Karasek's model in the literature (as well as variations such as the demand-control-support model), empirical evidence for this model is mixed (Totterdell, Wood, and Wall, 2006). (ispub.com)
- Propriety of Posteriors in Structured Additive Regression Models: Theory and Empirical Evidence. (uni-muenchen.de)
Diabetes1
- Age, gender, drug dosage, comorbidities of diabetes and heart failure (HF), and characteristics of the first hospitalization due to IS were all adjusted in models. (frontiersin.org)