TY - JOUR. T1 - Is aspirin effective in women undergoing in vitro fertilization (IVF)? Results from an individual patient data meta-analysis (IPD MA). AU - Groeneveld, E.. AU - Broeze, K. A.. AU - Lambers, M. J.. AU - Haapsamo, M.. AU - Dirckx, K.. AU - Schoot, B. C.. AU - Salle, B.. AU - Duvan, C. I.. AU - Schats, R.. AU - Mol, B. W.. AU - Hompes, P. G.A.. PY - 2011/7/1. Y1 - 2011/7/1. N2 - Background: Aspirin is believed to improve the outcome of IVF, but previous conventional meta-analyses on the subject are conflicting. Therefore, we performed a meta-analysis with individual patient data (IPD MA) of randomized clinical trials (RCTs) on the subject. Methods: A systematic literature search was conducted to identify RCTs assessing the effectiveness of aspirin in IVF. Authors were asked to share their original data. In a one step meta-analytic approach, the treatment effect of aspirin was estimated with odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression, based on the ...
BACKGROUND: Individual participant data (IPD) meta-analyses that obtain raw data from studies rather than summary data typically adopt a two-stage approach to analysis whereby IPD within trials generate summary measures, which are combined using standard meta-analytical methods. Recently, a range of one-stage approaches which combine all individual participant data in a single meta-analysis have been suggested as providing a more powerful and flexible approach. However, they are more complex to implement and require statistical support. This study uses a dataset to compare two-stage and one-stage models of varying complexity, to ascertain whether results obtained from the approaches differ in a clinically meaningful way. METHODS AND FINDINGS: We included data from 24 randomised controlled trials, evaluating antiplatelet agents, for the prevention of pre-eclampsia in pregnancy. We performed two-stage and one-stage IPD meta-analyses to estimate overall treatment effect and to explore potential
Medical education Comparing medical knowledge of osteopathic medical trainees in DO and MD programs: A random effect meta-analysis LINJUN SHEN, PhD; THOMAS CAVALIER!, DO; MICHAEL CLEARFIELD, DO; JOSEPH SMOLEY, PhD The authors used random effect meta-analysis to synthesize eight mean score differences of the Part BI/Level 3 examinations of the National Board of Osteo-pathic Medical Examiners (NBOME) between osteopathic medical trainees in DO residency programs and osteopathic medical trainees in MD programs. The anal-ysis involved 6001 trainees and all Part III or Level 3 examinations since 1992. The average mean score difference was not significantly different from zero; however, the estimates of true effect sizes of each examination varied substantially. The findings indicate that, overall, medical knowledge of osteopathic trainees in MD and DO residency programs is compatible at the time they took the exam-inations. However, a large variation of effect size suggests the need for further ...
TY - JOUR. T1 - The Meta VCI Map consortium for meta-analyses on strategic lesion locations for vascular cognitive impairment using lesion-symptom mapping. T2 - Design and multicenter pilot study. AU - Meta VCI Map consortium. AU - Calgary Normative Study group. AU - Framingham Heart Study group. AU - The Dutch Parelsnoer Institute - Neurodegenerative diseases group. AU - TABASCO group. AU - Weaver, Nick A.. AU - Zhao, Lei. AU - Biesbroek, J. Matthijs. AU - Kuijf, Hugo J.. AU - Aben, Hugo P.. AU - Bae, Hee Joon. AU - Caballero, Miguel Á.A.. AU - Chappell, Francesca M.. AU - Chen, Christopher P.L.H.. AU - Dichgans, Martin. AU - Duering, Marco. AU - Georgakis, Marios K.. AU - van der Giessen, Ruben S.. AU - Gyanwali, Bibek. AU - Hamilton, Olivia K.L.. AU - Hilal, Saima. AU - vom Hofe, Elise M.. AU - de Kort, Paul L.M.. AU - Koudstaal, Peter J.. AU - Lam, Bonnie Y.K.. AU - Lim, Jae Sung. AU - Makin, Stephen D.J.. AU - Mok, Vincent C.T.. AU - Shi, Lin. AU - Valdés Hernández, Maria C.. AU - ...
TY - JOUR. T1 - Repeat prenatal corticosteroid prior to preterm birth. T2 - A systematic review and individual participant data meta-analysis for the PRECISE study group (prenatal repeat corticosteroid international IPD study group: Assessing the effects using the best level of evidence) - study protocol. AU - Crowther, Caroline A.. AU - Aghajafari, Fariba. AU - Askie, Lisa M.. AU - Asztalos, Elizabeth V.. AU - Brocklehurst, Peter. AU - Bubner, Tanya K.. AU - Doyle, Lex W.. AU - Dutta, Sourabh. AU - Garite, Thomas J.. AU - Guinn, Debra A.. AU - Hallman, Mikko. AU - Hannah, Mary E.. AU - Hardy, Pollyanna. AU - Maurel, Kimberly. AU - Mazumder, Premasish. AU - McEvoy, Cynthia (Cindy). AU - Middleton, Philippa F.. AU - Murphy, Kellie E.. AU - Peltoniemi, Outi M.. AU - Peters, Dawn. AU - Sullivan, Lisa. AU - Thom, Elizabeth A.. AU - Voysey, Merryn. AU - Wapner, Ronald J.. AU - Yelland, Lisa. AU - Zhang, Sasha. PY - 2012/2/12. Y1 - 2012/2/12. N2 - Background: The aim of this individual participant ...
Fingerprint Dive into the research topics of Prognostic factors for adolescent knee pain: an individual participant data meta-analysis of 1281 patients. Together they form a unique fingerprint. ...
PubMed journal article Use of statins and fracture: results of 4 prospective studies and cumulative meta-analysis of observational studies and controlled trial were found in PRIME PubMed. Download Prime PubMed App to iPhone or iPad.
The objective of the present study was to review previous investigations on the association of haplotypes in the G-protein β3 subunit (GNB3) gene with representative cardiovascular risk factors/phenotypes: hypertension, overweight, and variation in the systolic and diastolic blood pressures (SBP and DBP, respectively) and as well as body mass index (BMI). A comprehensive literature search was undertaken in Pubmed, Web of Science, EMBASE, Biological Abstracts, LILACS and Google Scholar to identify potentially relevant articles published up to April 2011. Six genetic association studies encompassing 16,068 participants were identified. Individual participant data were obtained for all studies. The three most investigated GNB3 polymorphisms (G-350A, C825T and C1429T) were considered. Expectation-maximization and generalized linear models were employed to estimate haplotypic effects from data with uncertain phase while adjusting for covariates. Study-specific results were combined through a ...
BACKGROUND: Calls have been made for increased access to individual participant data (IPD) from clinical trials, to ensure that complete evidence is available. However, despite the obvious benefits, progress towards this is frustratingly slow. In the meantime, many systematic reviews have already collected IPD from clinical trials. We propose that a central repository for these IPD should be established to ensure that these datasets are safeguarded and made available for use by others, building on the strengths and advantages of the collaborative groups that have been brought together in developing the datasets. OBJECTIVE: Evaluate the level of support, and identify major issues, for establishing a central repository of IPD. DESIGN: On-line survey with email reminders. PARTICIPANTS: 71 reviewers affiliated with the Cochrane Collaborations IPD Meta-analysis Methods Group were invited to participate. RESULTS: 30 (42%) invitees responded: 28 (93%) had been involved in an IPD review and 24 (80%) had been
Meta-analysis has a long history within the medical sciences and epidemiology [1,2,3]. The main goal of a meta-analysis is to improve the precision of a specific effect size of a treatment or an exposure on a clinical or disease outcome by pooling or combining multiple studies. It is frequently conducted within a systematic review of the scientific literature to guarantee that studies with appropriate information are not ignored or overlooked and to make sure that the pooled estimate represents an unbiased and precise estimate of the true effect size. Moreover, the pooled effect estimate is evaluated in the context of study heterogeneity. In case substantial heterogeneity in the effect sizes across studies is present, the pooled estimate is considered less reliable or even questionable. Thus not only the pooled estimate must be unbiased, also the estimate of the measure of heterogeneity should be correct. Within the area of medical statistics, meta-analysis has evolved into an important and rich ...
A multivariate meta-analysis of two or more correlated outcomes is expected to improve precision compared with a series of independent, univariate meta-analyses especially when there are studies reporting some but not all outcomes. Multivariate meta-analysis requires estimates of the within-study correlations, which are seldom available. Existing methods for analysing multiple outcomes simultaneously are limited to pairwise treatment comparisons. We propose a model for a joint, simultaneous synthesis of multiple dichotomous outcomes in a network of interventions and introduce a simple way to elicit expert opinion for the within-study correlations by utilizing a set of conditional probability parameters. We implement our multiple-outcomes network meta-analysis model within a Bayesian framework, which allows incorporation of expert information. As an example, we analyse two correlated dichotomous outcomes, response to the treatment and dropout rate, in a network of pharmacological interventions for acute
A multivariate meta-analysis of two or more correlated outcomes is expected to improve precision compared with a series of independent, univariate meta-analyses especially when there are studies reporting some but not all outcomes. Multivariate meta-analysis requires estimates of the within-study correlations, which are seldom available. Existing methods for analysing multiple outcomes simultaneously are limited to pairwise treatment comparisons. We propose a model for a joint, simultaneous synthesis of multiple dichotomous outcomes in a network of interventions and introduce a simple way to elicit expert opinion for the within-study correlations by utilizing a set of conditional probability parameters. We implement our multiple-outcomes network meta-analysis model within a Bayesian framework, which allows incorporation of expert information. As an example, we analyse two correlated dichotomous outcomes, response to the treatment and dropout rate, in a network of pharmacological interventions for acute
Network meta-analyses are increasingly used to determine the best available healthcare interventions among all existing treatments for one specific disease. We showed that the conduct, reporting and interpretation of network meta-analyses was questionable. Particularly, the search strategy, assessment of risk of bias and publication bias were inappropriate in most publications. Furthermore, we showed that treatment rankings usually reported with no credibility interval have a substantial degree of imprecision, with a 50% or greater probability that the best-ranked treatment was actually not the best in 28% of networks. We also investigated whether conventional meta-analyses meet clinicians and patients needs. Our results revealed a substantial waste of research, with more than 40% of treatments, treatment comparisons, and trials not covered by existing systematic reviews. We developed a new paradigm, the live cumulative network meta-analysis, a single network meta-analysis covering all ...
An Individual Patient Data (IPD) meta-analysis is often considered the gold-standard for synthesising survival data from clinical trials. An IPD meta-analysis can be achieved by either a two-stage or a one-stage approach, depending on whether the trials are analysed separately or simultaneously. A range of one-stage hierarchical Cox models have been previously proposed, but these are known to be computationally intensive and are not currently available in all standard statistical software. We describe an alternative approach using Poisson based Generalised Linear Models (GLMs). We illustrate, through application and simulation, the Poisson approach both classically and in a Bayesian framework, in two-stage and one-stage approaches. We outline the benefits of our one-stage approach through extension to modelling treatment-covariate interactions and non-proportional hazards. Ten trials of hypertension treatment, with all-cause death the outcome of interest, are used to apply and assess the approach. We
An Individual Patient Data (IPD) meta-analysis is often considered the gold-standard for synthesising survival data from clinical trials. An IPD meta-analysis can be achieved by either a two-stage or a one-stage approach, depending on whether the trials are analysed separately or simultaneously. A range of one-stage hierarchical Cox models have been previously proposed, but these are known to be computationally intensive and are not currently available in all standard statistical software. We describe an alternative approach using Poisson based Generalised Linear Models (GLMs). We illustrate, through application and simulation, the Poisson approach both classically and in a Bayesian framework, in two-stage and one-stage approaches. We outline the benefits of our one-stage approach through extension to modelling treatment-covariate interactions and non-proportional hazards. Ten trials of hypertension treatment, with all-cause death the outcome of interest, are used to apply and assess the approach. We
We consider random effects meta-analysis where the outcome variable is the occurrence of some event of interest. The data structures handled are where one has one or more groups in each study, and in each group either the number of subjects with and without the event, or the number of events and the …
An application of multivariate meta-analysis for pooling estimates of non-linear associations from multiple studies. The code included is applicable beyond the specific setting of time series analysis of temperature-health relationships. The example illustrate the analysis in the article: Gasparrini A, Armstrong B, Kenward MG. Multivariate meta-analysis for non-linear and other multi-parameter associations. Statistics in Medicine. 2012;31(29):3821-39. The original example included in the article was based on data from the National Mortality, Morbidity, and Air Pollution Study (NMMAPS), which at the time of the publication was available through the R package NMMAPSlite. Unfortunately, the data are not available any more and the package NMMAPSlite has been archived. In order to provide a working example, the analysis has been replaced with a similar analysis on a publicly available dataset. The material covers: [1] regEngWales.csv stores the dataset used to perform an illustrative example, ...
TY - JOUR. T1 - Selenium and Prostate Cancer. T2 - Analysis of Individual Participant Data From Fifteen Prospective Studies. AU - Allen, Naomi E.. AU - Travis, Ruth C.. AU - Appleby, Paul N.. AU - Albanes, Demetrius. AU - Barnett, Matt J. AU - Black, Amanda. AU - Bueno-de-Mesquita, H Bas. AU - Deschasaux, Mélanie. AU - Galan, Pilar. AU - Goodman, Gary E.. AU - Goodman, Phyllis J.. AU - Gunter, Marc J.. AU - Heliövaara, Markku. AU - Helzlsouer, Kathy J. AU - Henderson, Brian E.. AU - Hercberg, Serge. AU - Knekt, Paul. AU - Kolonel, Laurence N.. AU - Lasheras, Christina. AU - Linseisen, Jakob. AU - Metter, E. Jeffrey. AU - Neuhouser, Marian L.. AU - Olsen, Anja. AU - Pala, Maria Valeria. AU - Platz, Elizabeth A. AU - Rissanen, Harri. AU - Reid, Mary E. AU - Schenk, Jeannette M. AU - Stampfer, Meir J. AU - Stattin, Pär. AU - Tangen, Catherine M. AU - Touvier, Mathilde. AU - Trichopoulou, Antonia. AU - van den Brandt, Piet A. AU - Key, Timothy J.. AU - Endogenous Hormones, Nutritional Biomarkers ...
Confidence intervals for the between-study variance in random-effects meta-analysis using generalised heterogeneity statistics: should we use unequal tails. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
We read with deep interest the article by Wang et al1 aimed to compare the efficacy of 20 non-steroidal anti-inflammatory drugs (NSAIDs) in the short-term treatment of ankylosing spondylitis (AS). This Bayesian network meta-analysis indicated that etoricoxib was more effective in reducing pain in AS than some other NSAIDs. The result was very useful in the decision-making process, especially for pain relief in treating patients with AS. However, there are some worthwhile issues that need to be explored.. First, it is commonly agreed that meta-analysis, including network meta-analysis, should assess heterogeneity, which may be defined as the presence of variation in true effect sizes underlying the different studies. Unfortunately, however, heterogeneity was not assessed in this network meta-analysis. Between-study heterogeneity indicates the presence of effect modifiers, and variability in relative treatment effects has a bad impact on the external validity of trial evidence, and limits the ...
Background: Frequently, interventions for a given health problem have never been compared in head-to-head randomized controlled trials. In this context, adjusted indirect comparisons based on network meta-analyses (NMAs) could answer the question posed by most healthcare professionals: what is the best intervention among the existing interventions for a specific condition? Objectives: To evaluate the trend in NMAs publication topic in medical electronic databases and in the top five impact factor journals in the Medicine, General and Internal category. Methods: A search strategy was performed in Medline (PubMed), EMBASE, and CENTRAL, since inception (Figure 1). We analysed the general yearly trend all together and separately by database and by journal. Results: During the analysed period, the reporting of studies mentioning NMA has increased since the beginning of the XXI century and markedly since 2009. EMBASE was the database with the highest cumulative number of references bout NMA and the ...
The continuous development and refinement of techniques is a key attribute of the discipline of surgery. Robust evidence derived from randomised clinical trials and subsequent synthesis using meta-analysis methods is therefore an indispensable tool in modern evidence-based surgical practice. This thesis aimed to address two challenges to the development of this evidence, namely the synthesis of trial data where multiple treatment comparisons exist, and the influence of sources of bias on the results of surgical randomised trials. Research synthesis typically employs pairwise meta-analysis methods to summarise trial data. However, there are more than two treatment options available for most conditions, meaning that data pertaining to all treatments cannot be incorporated using pairwise methodology. Network meta-analysis allows for the simultaneous comparison of multiple treatments and enables their ranking in terms of benefit and harm. This thesis used two different examples to explore this ...
BACKGROUND: The last 30 years have seen an exponential increase in metaanalyses. By combining multiple studies, metaanalysis can provide an overview of the totality of evidence on a particular question and the statistical power needed to reduce random error and produce precise estimates of even modest effect sizes. This capability is of particular value when many small studies address similar questions [such as in the investigation of novel cardiovascular disease (CVD) biomarkers]. To provide reliable evidence, however, metaanalyses must be undertaken robustly. CONTENT: In this review, we describe the major issues to consider when designing and conducting metaanalyses, including the design of constituent studies, selection criteria, assessment of exposures and disease outcomes, and control of bias and confounding. Some of the potential challenges and pitfalls associated with metaanalysis are examined, and their consequences are considered. We use 2 examples of novel biomarkers for CVD-homocysteine and
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Meta-analysis is the use of statistical methods to combine evidence across studies for the purposes of drawing general conclusions. The results of each study are summarized by a quantitative index called an effect size, and then the effect sizes from each study are combined across studies to obtain an overall summary effect. Meta-analysis differs from secondary analysis because the latter involves analysis of the raw data from each study, but meta-analysis typically uses only summaries of the raw data from each study (the effect sizes), not the raw data itself. Meta-analyses may have any of several primary objectives. In many cases, meta-analyses are carried out to obtain a summary of average effects. In other cases, they may be carried out to study differential effects of a treatment on different subject populations, different treatment contexts, different variations of a treatment, or different outcome measures. It is also common for meta-analysts to use their results to identify areas of ...
What is the little thing you can do to increase reproducibility, replicability and trust in science? How can reporting quality interfere with reproducibility issues and overall trust in science results? With that question in mind, we participated in the Reproducibility, Replicability and Trust in Science conference organised by the Wellcome Genome Campus from 9 to 11.... ...
The purpose of the Bulletin of Economics and Meta-Analysis (BEMA) is to provide a forum for recent meta-analyses in economics, to publish fresh research quickly, and thereby to improve the quality of meta-analytic research before it is submitted to traditional scholarly journals. We seek to publish, electronically, short notes and longer abstracts that briefly sketch recent research about meta-analysis or that employs meta-analysis. It is assumed that all notes submitted will contain links to longer working papers. Authors wishing to have their notes considered for publication in BEMA should submit them for review to: [email protected] ...
Fast and easy meta-analysis software. Research synthesis, systematic review for finding effect size, creating forest plots, and much more. Free trial.
Background and aims: Our study aims to evaluate the efficacy and safety of long-term treatment of statins for coronary heart disease (CHD). Methods: Efficacy outcomes included changes in blood lipids, risk of CHD mortality and all-cause mortality. Safety outcomes were evaluated by the risk of adverse events (AE). Bayesian network meta-analysis was used to compare the direct and indirect effects between different statins. Results: The systematic review showed that levels of blood lipids decreased during statin treatment. High dose of atorvastatin was the most obvious treatment for the reduction of blood lipids. Network meta-analysis showed that statins were significantly more effective than the control in reducing the risk of CHD mortality (Odds Ratio (OR) 0.69, 95% CI 0.61-0.77) and all-cause mortality (OR 0.84, 95% CI 0.80-0.87). In terms of reducing the risk of CHD morality, fluvastatin (77.3%), atorvastatin (72.3%) and lovastatin (68.4%) had higher cumulative probability than other statins, ...
Compute variance-covariance matrix for multivariate meta-analysis. Effect sizes include correlation (r), mean difference (MD), standardized mean difference (SMD), log odds ratio (logOR), log risk ratio (logRR), and risk difference (RD).. ...
Evidence-based health-care decision making requires comparisons of all relevant competing interventions. In the absence of randomized, controlled trials involving a direct comparison of all treatments of interest, indirect treatment comparisons and network meta-analysis provide useful evidence for j …
BACKGROUND: Understanding of the genetic basis of type 2 diabetes (T2D) has progressed rapidly, but the interactions between common genetic variants and lifestyle risk factors have not been systematically investigated in studies with adequate statistical power. Therefore, we aimed to quantify the combined effects of genetic and lifestyle factors on risk of T2D in order to inform strategies for prevention. METHODS AND FINDINGS: The InterAct study includes 12,403 incident T2D cases and a representative sub-cohort of 16,154 individuals from a cohort of 340,234 European participants with 3.99 million person-years of follow-up. We studied the combined effects of an additive genetic T2D risk score and modifiable and non-modifiable risk factors using Prentice-weighted Cox regression and random effects meta-analysis methods. The effect of the genetic score was significantly greater in younger individuals (p for interaction = 1.20×10-4). Relative genetic risk (per standard deviation [4.4 risk alleles]) was
Health,A recent meta-analysis of five major breast cancer trials has confirme...At the ESMO Conference Lugano Issa Dahabreh from the University...All the trials compared disease-free survival overall survival and...Up to a quarter of all breast cancers express large amounts of t...The results showed that combining trastuzumab with chemotherapy ...,Combination,of,Tratuzumab,and,Chemotherapy,Yields,Better,Results,for,Breast,Cancer,medicine,medical news today,latest medical news,medical newsletters,current medical news,latest medicine news
Here are three studies (for all abstracts & links see below) highlighting the increasingly encouraging results being reported for internet-delivered psychological interventions. Vant Hof, Cuijpers et al report on ... a systematic review of meta-analyses on the efficacy of self-help interventions, including internet-guided therapy, for depression and anxiety disorders. They conclude that the 13 meta-analyses indicate self-help methods are effective in a range of different disorders, including depression and anxiety disorders. Most meta-analyses found relatively large effect sizes for self-help treatments, independent of the type of self-help, and comparable to effect sizes for face-to-face treatments (see below for abstracts and links to the six research papers mentioned). Riper, Kramer et al describe how an experimental internet-delivered self-help alcohol reduction intervention transferred well to being made more generally available. The authors conclude that .... ...
Here are three studies (for all abstracts & links see below) highlighting the increasingly encouraging results being reported for internet-delivered psychological interventions. Vant Hof, Cuijpers et al report on ... a systematic review of meta-analyses on the efficacy of self-help interventions, including internet-guided therapy, for depression and anxiety disorders. They conclude that the 13 meta-analyses indicate self-help methods are effective in a range of different disorders, including depression and anxiety disorders. Most meta-analyses found relatively large effect sizes for self-help treatments, independent of the type of self-help, and comparable to effect sizes for face-to-face treatments (see below for abstracts and links to the six research papers mentioned). Riper, Kramer et al describe how an experimental internet-delivered self-help alcohol reduction intervention transferred well to being made more generally available. The authors conclude that .... ...
The number of studies on the association between clock genes polymorphisms and cancer susceptibility has increased over the last years but the results are often conflicting and no comprehensive overview and quantitative summary of the evidence in this field is available. RESULTS: Literature search identified 27 eligible studies comprising 96756 subjects (cases: 38231) and investigating 687 polymorphisms involving 14 clock genes. Overall, 1025 primary and subgroup meta-analyses on 366 gene variants were performed. Study distribution by tumor was as follows: breast cancer (n=15), prostate cancer (n=3), pancreatic cancer (n=2), non-Hodgkins lymphoma (n=2), glioma (n=1), chronic lymphocytic leukemia (n=1), colorectal cancer (n=1), non-small cell lung cancer (n=1) and ovarian cancer (n=1).We identified 10 single nucleotide polymorphisms (SNPs) significantly associated with cancer risk: NPAS2 rs10165970 (mixed and breast cancer shiftworkers), rs895520 (mixed), rs17024869 (breast) and rs7581886 ...
TY - JOUR. T1 - Dealing with missing standard deviation and mean values in meta-analysis of continuous outcomes: a systematic review. AU - Weir, Christopher J. AU - Butcher, Isabella. AU - Assi, Valentina. AU - Lewis, Stephanie C. AU - Murray, Gordon. AU - Langhorne, Peter. AU - Brady, Marian. N1 - Acceptance in SAN OA article Funding: This project was funded by The Stroke Association, grant number 2012/05 with additional support from the Rosetrees Trust.. PY - 2018/3/7. Y1 - 2018/3/7. N2 - Abstract BackgroundRigorous, informative meta-analyses rely on availability of appropriate summary statistics or individual participant data. For continuous outcomes, especially those with naturally skewed distributions, summary information on the mean or variability often goes unreported. While full reporting of original trial data is the ideal, we sought to identify methods for handling unreported mean or variability summary statistics in meta-analysis.MethodsWe undertook two systematic literature reviews ...
A study appeared this week sure to drive members of the low-fat and vegan tribes sprinting for their Protexid.. Ron Krauss and his group published a paper in the Articles in Press section of the American Journal of Clinical Nutrition (AJCN) stating there is no evidence that saturated fat intake increases the risk for heart disease. The paper, titled Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease, is not a study per se, but is a meta-analysis, a compilation of numerous studies looking at the relationship between saturated fat intake and the risk for developing heart disease.. As Ive discussed before on these pages, meta-analyses are not my favorite types of studies. Ive attacked them when theyve been used to prove the low-fat diets are better, so I cant very well embrace meta-analyses when they present a conclusion I agree with. And I really cant embrace meta-analyses when they are compilations of observational studies, ...
In this article, we provide guidance on how to systematically review and quantitatively synthesize the predictive performance of a prediction model. Although we focused on systematic review and meta-analysis of a prognostic model, all guidance can similarly be applied to the meta-analysis of a diagnostic prediction model. We discussed how to define the systematic review question, identify the relevant prediction model studies from the literature, critically appraise the identified studies, extract relevant summary statistics, quantitatively summarise the extracted estimates, and investigate sources of between-study heterogeneity.. Meta-analysis of a prediction models predictive performance bears many similarities to other types of meta-analysis. However, in contrast to synthesis of randomised trials, heterogeneity is much more likely in meta-analysis of studies assessing the predictive performance of a prediction model, owing to the increased variation of eligible study designs, increased ...
There is an emerging body of literature relating to the effectiveness of frequent aerobic exercise as a prophylactic for age-associated dysfunction of large arteries, yet systematic evaluation and precise estimate of this effect is unknown. We conducted a systematic review and meta-analysis of controlled studies examining flow mediated dilatation (FMD) of athletic older persons and otherwise healthy sedentary counterparts to (i) compare FMD as a determinant of endothelial function between athletes and sedentary individuals and, (ii) summarize the effect of exercise training on FMD in studies of sedentary aging persons. Studies were identified from systematic search of major electronic databases from inception to January 2018. Study quality was assessed before conducting a random effects meta-analysis to calculate a pooled ES (mean difference) with 95% CIs. Thirteen studies [4 interventional (n = 125); 10 cross-sectional [including one study from the interventional analysis; (n = 485)] with age ...
Objective: Spontaneous or experimentally induced high blood pressure (BP) is associated with reduced pain perception, known as BP-related hypoalgesia. Despite its clinical implications, such as the interference with early detection of myocardial infarction in at risk groups, the size of the association between high BP and pain has not yet been quantified. Moreover, the distinct association between high BP and physiological or psychological components of pain has not yet been considered so far. The aim of this study was to overcome this gap by performing separate meta-analyses on nociceptive response versus quantifiable perceptual measures of pain in relation to high BP. Methods: PubMed and Web of Knowledge databases were searched for English language studies conducted in humans. Fifty-nine studies were eligible for the analyses. Pooled effect sizes (Hedges g) were compared. Random effect models were used. Results show that higher BP is significantly associated with lower nociceptive response ...
Findings Twenty NMAs were eligible for inclusion. The number of randomised controlled trials per NMA ranged from 11 to 234, and included between 801 to more than 26 000 participants. Overall, antidepressants were found to be efficacious and tolerable agents for several disorders based on rankings (45%) or statistical significance (55%). The majority of NMAs in this review adhered to guidelines by including a network diagram (70%), assessing consistency (75%), making use of a random effects model (75%), providing information on the model used to fit the data (75%) and adjusting for covariates (75%). ...
Results from the present study add to the growing body of studies showing that iSMIs can be an accessible and effective way of reducing work-related stress. In line with our expectations, we found that the guided iSMI effectively reduces symptoms of perceived stress in a sample of distressed managers. Analyses also indicate effects on other mental health and work-related outcomes. Long-term effects were seen on several of the mental health-related outcomes (perceived stress, insomnia and cognitive weariness). However, effects on the work-related outcomes were not sustained at the 6 months follow-up.. The effects found in the present study were larger compared with those found in our previous iSMIs trials (d≈0.60),23 25 however within CI of guided interventions (Cohens d=0.64, 95% CI 0.50 to 0.79) presented in a recently published meta-analyses on iSMI.24 Compared with regular face-to-face CBT-based SMIs, d=0.68 to 1.16,17 our effects are lower on stress-related measures (perceived stress, ...
It is considered that fruit and vegetable (F&V) protect against oesophagus and gastric cancer (GC). However, 2 recent meta-analyses suggest that the strength of association on GC seems to be weaker for vegetables than for fruit and weaker in cohort than in case-control studies. No evidence exists from cohort studies about adenocarcinoma of oesophagus (ACO). In 521,457 men and women participating in the EPIC cohort in 10 European countries, information of diet and lifestyle was collected at baseline. After an average of 6.5 years of follow-up, a total of 330 GC and 65 ACO, confirmed and classified by a panel of pathologists, was used for the analysis. We examined the relation between F&V intake and GC and ACO. A calibration study in a sub-sample was used to control diet measurement errors. In a sub-sample of cases and a random sample of controls, antibodies against Helicobacter pylori (Hp) were measured and interactions with F&V were examined in a nested case-control study. We observed no ...
Meta-analysis is a formal quantitative method for pooling scientific data reported from multiple studies, therefore allowing for an evaluation of the treatment or exposure effect on a specific health outcome. In a meta-analysis, researchers assess heterogeneity across studies, examine subgroups of studies to determine if selected subsets of the research data provide similar or different results, and calculate summary relative risk estimates. A meta-analysis provides a statistically precise summary risk estimate, as well as a better understanding of the consistency of reported findings (or lack of) in the research literature. A meta-analysis is distinct from a qualitative or narrative review in that a meta-analysis involves a systematic review of the literature, relevant data extraction, and quantitative analyses of data across multiple studies. A pooled analysis is similar to a traditional meta-analysis, except that participant-level data from multiple studies are combined and analyzed as a ...
Meta-analysis can be used to examine differences in treatment effects across trials; however, the fact that randomised trials are included in meta-analyses does not mean that comparisons between trials are also randomised comparisons. Meta-analytic subgroup analyses, like subgroup analyses within trials, are prone to bias and need to be interpreted with caution. A more reliable way of assessing differences in treatment effects is to relate outcome to some underlying patient characteristic on a continuous, or ordered, scale. The underlying level of risk is a key variable which is often related to a given treatment effect, with patients at higher risk receiving more benefit then low risk patients. Individual patient data, rather than published summary statistics, are often required for meaningful subgroup analyses. ...
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Caroline Crowther, Philippa Middleton, Merryn Voysey, Lisa Askie, Lelia Duley, et al.. Assessing the neuroprotective benefits for babies of antenatal magnesium sulphate: An individual participant data meta-analysis. PLoS Medicine, Public Library of Science, 2017, 14 (10), pp.e1002398. ⟨10.1371/journal.pmed.1002398⟩. ⟨hal-02452278⟩ ...
Pooling of data from 14,874 women in an individual participant data meta-analysis by Nicola Low and colleagues reveals that some intravaginal practices increase the risk of HIV acquisition.
Dietary Reference Values (DRVs) for vitamin D have a key role in the prevention of vitamin D deficiency. However, despite adopting similar risk assessment protocols, estimates from authoritative agencies over the last 6 years have been diverse. This may have arisen from diverse approaches to data analysis. Modelling strategies for pooling of individual subject data from cognate vitamin D randomized controlled trials (RCTs) are likely to provide the most appropriate DRV estimates. Thus, the objective of the present work was to undertake the first-ever individual participant data (IPD)-level meta-regression, which is increasingly recognized as best practice, from seven winter-based RCTs (with 882 participants ranging in age from 4 to 90 years) of the vitamin D intake-serum 25-hydroxyvitamin D (25(OH)D) dose-response. Our IPD-derived estimates of vitamin D intakes required to maintain 97.5% of 25(OH)D concentrations >25, 30, and 50 nmol/L across the population are 10, 13, and 26 µg/day, respectively.
TY - JOUR. T1 - A collaborative analysis of individual participant data from 19 prospective studies assesses circulating vitamin D and prostate cancer risk. AU - Travis, Ruth C. AU - Martin, Richard. AU - Donovan, Jenny. PY - 2018/11/13. Y1 - 2018/11/13. KW - prostate cancer. KW - vitamin D. KW - 25-hydroxyvitamin D. KW - 1,25-dihydroxyvitamin D. KW - pooled analysis. U2 - 10.1158/0008-5472.CAN-18-2318. DO - 10.1158/0008-5472.CAN-18-2318. M3 - Article (Academic Journal). C2 - 30425058. JO - Cancer Research. JF - Cancer Research. SN - 0008-5472. ER - ...
OBJECTIVES: Early saphenous vein graft (SVG) occlusion is typically attributed to technical factors. We aimed at exploring clinical, anatomical, and operative factors associated with the risk of early SVG occlusion (within 12 months postsurgery). METHODS: Published literature in MEDLINE was searched for studies reporting the incidence of early SVG occlusion. Individual patient data (IPD) on early SVG occlusion were used from the SAFINOUS-CABG Consortium. A derivation (n = 1492 patients) and validation (n = 372 patients) cohort were used for model training (with 10-fold cross-validation) and external validation respectively. RESULTS: In aggregate data meta-analysis (48 studies, 41,530 SVGs) the pooled estimate for early SVG occlusion was 11%. The developed IPD model for early SVG occlusion, which included clinical, anatomical, and operative characteristics (age, sex, dyslipidemia, diabetes mellitus, smoking, serum creatinine, endoscopic vein harvesting, use of complex grafts, grafted target vessel, and
article{2a540d9f-73ba-41d7-8442-fe16f20afb72, abstract = {,p,Emerging evidence suggests that the basis for variation in late-life mobility is attributable, in part, to genetic factors, which may become increasingly important with age. Our objective was to systematically assess the contribution of genetic variation to gait speed in older individuals. We conducted a meta-analysis of gait speed GWASs in 31,478 older adults from 17 cohorts of the CHARGE consortium, and validated our results in 2,588 older adults from 4 independent studies. We followed our initial discoveries with network and eQTL analysis of candidate signals in tissues. The meta-analysis resulted in a list of 536 suggestive genome wide significant SNPs in or near 69 genes. Further interrogation with Pathway Analysis placed gait speed as a polygenic complex trait in five major networks. Subsequent eQTL analysis revealed several SNPs significantly associated with the expression of PRSS16, WDSUB1 and PTPRT, which in addition to the ...
Downloadable! Despite the vast literature dealing with the impact of the subsidies on world cotton prices, there is no consensus regarding the quantification of these effects. The aim of this paper is to contribute to this literature through the implementation of a meta-regression analysis. This methodology allows us to: (i) identify the main sources of heterogeneity between the primary studies, (ii) give some tracks to improve the modeling, (iii) provide a reliable quantification of the removal of subsidies on world cotton prices. Relying on the estimation of various models to derive robust results, our findings show that a withdrawal of US subsidies would increase the world cotton price by around 10%.
© 2017 Tucker et al. Background: Self-monitoring of blood pressure (BP) appears to reduce BP in hypertension but important questions remain regarding effective implementation and which groups may benefit most. This individual patient data (IPD) meta-analysis was performed to better understand the effectiveness of BP self-monitoring to lower BP and control hypertension. Methods and findings: Medline, Embase, and the Cochrane Library were searched for randomised trials comparing self-monitoring to no self-monitoring in hypertensive patients (June 2016). Two reviewers independently assessed articles for eligibility and the authors of eligible trials were approached requesting IPD. Of 2,846 articles in the initial search, 36 were eligible. IPD were provided from 25 trials, including 1 unpublished study. Data for the primary outcomes-change in mean clinic or ambulatory BP and proportion controlled below target at 12 months-were available from 15/19 possible studies (7,138/8,292 [86%] of randomised
Granulocyte colony stimulating factor (G-CSF) may enhance recovery from stroke through neuroprotective mechanisms if administered early, or neurorepair if given later. Several small trials suggest administration is safe but effects on efficacy are unclear. We searched for randomised controlled trials (RCT) assessing G-CSF in patients with hyperacute, acute, subacute or chronic stroke, and asked Investigators to share individual patient data on baseline characteristics, stroke severity and type, end-of trial modified Rankin Scale (mRS), Barthel Index, haematological parameters, serious adverse events and death. Multiple variable analyses were adjusted for age, sex, baseline severity and time-to-treatment. Individual patient data were obtained for 6 of 10 RCTs comprising 196 stroke patients (116 G-CSF, 80 placebo), mean age 67.1 (SD 12.9), 92% ischaemic, median NIHSS 10 (IQR 5-15), randomised 11 days (interquartile range IQR 4-238) post ictus; data from three commercial trials were not shared. ...
Order books on meta-analysis and systematic reviews authored by experts (including Larry Hedges, Terri Pigott, Hannah Rothstein).
Objectives: To assess the accuracy in diagnosing heart failure of clinical features and potential primary care investigations, and to perform a decision analysis to test the impact of plausible diagnostic strategies on costs and diagnostic yield in the UK health-care setting. Data sources: MEDLINE and CINAHL were searched from inception to 7 July 2006. Grey literature databases and conference proceedings were searched and authors of relevant studies contacted for data that could not be extracted from the published papers. Review methods: A systematic review of the clinical evidence was carried out according to standard methods. Individual patient data (IPD) analysis was performed on nine studies, and a logistic regression model to predict heart failure was developed on one of the data sets and validated on the other data sets. Cost-effectiveness modelling was based on a decision tree that compared different plausible investigation strategies. Results: Dyspnoea was the only symptom or sign with high
Brindle, R. C., Ginty, A. T., Phillips, A. C. and Carroll, D. (2014), A tale of two mechanisms: A meta-analytic approach toward understanding the autonomic basis of cardiovascular reactivity to acute psychological stress. Psychophysiology, 51: 964-976. doi: 10.1111/psyp.12248 ...
See related article, pp 642-653. In this issue of the journal, Verdecchia et al1 report an important analysis of the accumulation of evidence comparing more versus less intensive blood pressure (BP)-lowering strategies. Their key message is critical for guidelines and practice internationally: with the addition of SPRINT (Systolic Blood Pressure Intervention Trial),2 this set of trials now provides compelling evidence that more intensive BP-lowering reduces stroke and myocardial infarction (MI), and significant reductions are now also seen in cardiovascular death and heart failure. The authors have also assessed sequential monitoring boundaries for each outcome, making the analogy of a hypothetical Data and Safety Monitoring Board (DSMB) assessing the accumulation of evidence in the field.. Before examining the implications, it is worth reviewing the techniques and aims of the cumulative meta-analysis and trial sequential analysis methods used by Verdecchia et al.1 Cumulative meta-analysis ...
The current study used a convenience sample of 95 SRs included across seven overview topics to provide empirical evidence on issues surrounding quality assessments of SRs in overviews. This study found that AMSTAR assessments and inter-rater reliability were higher for Cochrane compared to non-Cochrane SRs; these results were consistent within each overview topic and for many of the individual questions of the AMSTAR tool. Minor challenges were encountered when assessing quality of SRs in the context of overviews, but decision rules were developed and recommendations for overview authors were provided. Results also suggested that inter-rater reliability of Cochrane and non-Cochrane SRs may be lower for SRs with moderate AMSTAR assessments and higher for SRs that were assessed as strong; inter-rater reliability may also be higher for non-Cochrane SRs assessed as weak. Consistent with a previous study [33], we found that the conclusions, but not the results, of Cochrane and non-Cochrane SRs ...
TY - JOUR. T1 - Meta-analysis of survey data. T2 - Application to health services research. AU - Rao, Sowmya R.. AU - Graubard, Barry I.. AU - Schmid, Christopher H.. AU - Morton, Sally C.. AU - Louis, Thomas A.. AU - Zaslavsky, Alan M.. AU - Finkelstein, Dianne M.. PY - 2008/6/1. Y1 - 2008/6/1. N2 - Traditionally, meta-analysis methods have been developed and used to combine data from several independent clinical trials as well as observational studies, but have not been as widely used in survey research. This paper describes the steps in conducting such a meta-analysis of surveys, to obtain a single summary estimate from a combination of individual-level and summary data. The methods are applied in the context of a project aimed at obtaining an estimate of the prevalence of use of electronic health records.. AB - Traditionally, meta-analysis methods have been developed and used to combine data from several independent clinical trials as well as observational studies, but have not been as ...
OBJECTIVES: To survey the frequency of use of indirect comparisons in systematic reviews and evaluate the methods used in their analysis and interpretation. Also to identify alternative statistical approaches for the analysis of indirect comparisons, to assess the properties of different statistical methods used for performing indirect comparisons and to compare direct and indirect estimates of the same effects within reviews. DATA SOURCES: Electronic databases. REVIEW METHODS: The Database of Abstracts of Reviews of Effects (DARE) was searched for systematic reviews involving meta-analysis of randomised controlled trials (RCTs) that reported both direct and indirect comparisons, or indirect comparisons alone. A systematic review of MEDLINE and other databases was carried out to identify published methods for analysing indirect comparisons. Study designs were created using data from the International Stroke Trial. Random samples of patients receiving aspirin, heparin or placebo in 16 centres were used
Background Four studies previously indicated that the effect of malaria infection during pregnancy on the risk of low birthweight (LBW; ,2,500 g) may depend upon maternal nutritional status. We investigated this dependence further using a large, diverse study population. Methods and findings We evaluated the interaction between maternal malaria infection and maternal anthropometric status on the risk of LBW using pooled data from 14,633 pregnancies from 13 studies (6 cohort studies and 7 randomized controlled trials) conducted in Africa and the Western Pacific from 1996-2015. Studies were identified by the Maternal Malaria and Malnutrition (M3) initiative using a convenience sampling approach and were eligible for pooling given adequate ethical approval and availability of essential variables. Study-specific adjusted effect estimates were calculated using inverse probability of treatment-weighted linear and log-binomial regression models and pooled using a random-effects model. The adjusted risk ...
PART A: META-ANALYSIS METHODOLOGY: THE BASICS Introduction: Meta-analysis: Its Development and Uses Defining Outcome Measures used for Combining via Meta-analysis Random Effects Models for Combining Study Estimates Exploring Between Study Heterogeneity Publication Bias Study Quality Sensitivity Analysis Reporting the Results of a Meta-analysis Fixed Effects Methods for Combining Study Estimates PART B: ADVANCED AND SPECIALIZED META-ANALYSIS TOPICS Bayesian Methods in Meta-analysis Meta Regression Meta-analysis of Different Types of Data Incorporating Study Quality into a Meta-analysis Meta-analysis of Multiple and Correlated Outcome Measures Meta-analysis of Epidemiological and other Observational Studies Generalised Synthesis of Evidence ...
Dear Editor. Having recently published a meta-analysis on the same clinical question,[1] it was with great interest that we read Michael et al.s systematic review of short vs. standard duration antibiotics for urinary tract infections in children.[2] Given the publication (in close succession) of two meta-analyses on the same question with (on the surface) strikingly different results, we thought a comment was in order. First, we applaud the authors on their methodologically sound review. The literature search was explicitly described and exhaustive. In fact, the authors identified a few studies that we had missed.[3-6] The study outcomes for meta-analysis (frequency of positive urine cultures at 0-7 days after treatment and at 10 days to 15 months after treatment, and development of resistant organisms and recurrent UTI) were relevant and clearly defined. The authors provided appropriate and important meta-analysis measures including summary relative risks and a quasi-NNT calculation with ...
T]his is a comprehensive and up-to-date compendium of all relevant aspects for meta-analysis conduction in ecology, evolution, and related topics. Scientists from these areas who already have some knowledge on meta-analysis will find valuable guidance.-Daniela Vetter, Quarterly Review of Biology. A superb guide to the conduct and interpretation of meta-analysis, from an exceptional team of international experts. This comprehensive manual covers essential concepts, steps, and standards for rigorous research synthesis in ecology and evolutionary biology. Its clear prose, helpful illustrations, and worked examples will be useful for beginners and experts alike. Highly recommended for use as a textbook or for self-study.-Julia Littell, Bryn Mawr College, coauthor of Systematic Reviews and Meta-Analysis. This is a well-written and valuable book, one that is unique within biology. The use of meta-analysis in ecology and evolution has reached the point where there is a need for a comprehensive, ...
Accurate representation of ecosystem processes in land models is crucial for reducing predictive uncertainty in energy and greenhouse gas feedbacks with the atmosphere. Here we describe an observational and modeling meta-analysis approach to benchmark land models, and apply the method to the land model CLM4.5 with two versions of belowground biogeochemistry. We focused our analysis on the above and belowground high-latitude ecosystem responses to warming and nitrogen addition, and identified mechanisms absent, or poorly parameterized in CLM4.5. While the two model versions predicted similar trajectories for soil carbon stocks following both types of perturbation, other variables (e.g., belowground respiration) differed from the observations in both magnitude and direction, indicating the underlying mechanisms are inadequate for representing high-latitude ecosystems. The observational synthesis attribute these differences to missing representations of microbial dynamics, characterization of above ...
TY - JOUR. T1 - Correction to. T2 - Epinephrine and short-term survival in cardiogenic shock: an individual data meta-analysis of 2583 patients (Intensive Care Medicine, (2018), 44, 6, (847-856), 10.1007/s00134-018-5222-9). AU - Léopold, Valentine. AU - Gayat, Etienne. AU - Pirracchio, Romain. AU - Spinar, Jindrich. AU - Parenica, Jiri. AU - Tarvasmäki, Tuukka. AU - Lassus, Johan. AU - Harjola, Veli Pekka. AU - Champion, Sébastien. AU - Zannad, Faiez. AU - Valente, Serafina. AU - Urban, Philip. AU - Chua, Horng Ruey. AU - Bellomo, Rinaldo. AU - Popovic, Batric. AU - Ouweneel, Dagmar M.. AU - Henriques, José P.S.. AU - Simonis, Gregor. AU - Lévy, Bruno. AU - Kimmoun, Antoine. AU - Gaudard, Philippe. AU - Basir, Mir Babar. AU - Markota, Andrej. AU - Adler, Christoph. AU - Reuter, Hannes. AU - Mebazaa, Alexandre. AU - Chouihed, Tahar. PY - 2018/11/1. Y1 - 2018/11/1. N2 - Because of a technical error, the code corresponding to the outcome for the Basir et al. cohort was mis-implemented in the ...
Expression quantitative trait loci (eQTLs) analysis is commonly used to identify genetic variants affecting gene regulation. While such studies provide insight into genetic associations, they generally consider only cis-acting SNPs, and fail to address tissue-specific effects that might influence eQTL associations. Here we applied a meta-analysis approach that jointly analyzes cis- and trans-eQTLs. Using data from twelve tissue types from the Genotype-Tissue Expression (GTEx) project V6, we identified hundreds of thousands significant eQTLs in each tissue (FDR , 10%), among which 12% to 42% were trans-eQTLs. By representing the associations between SNPs and genes as links in a bipartite graph, we discovered that these eQTL networks organize into dense, highly modular communities, driven by biological processes. While some communities are enriched for processes relevant to the tissue of origin, other communities can be retrieved in several tissues and are enriched for general functions. We found ...
I am raising my recommendation of 1,000 IU of vitamin D per day to 2,000 IU per day. Since 2005, when I raised it from 400 to 1,000 IU, clinical evidence has been accumulating to suggest that a higher dose is more appropriate to help maintain optimum health.. We have known for many years that we need vitamin D to facilitate calcium absorption and promote bone mineralization. But newer research has shown that we also need it for protection against a number of serious diseases. In recent years, scientists have discovered that it may help to prevent several cancers, cardiovascular disease, autoimmune disorders, psoriasis, diabetes, psychosis, and respiratory infections including colds and flu.. To focus particularly on cancer prevention, two recent meta-analyses (in which data from multiple studies is combined) conducted by the Moores Cancer Center at the University of California at San Diego and colleagues suggested that raising blood levels of vitamin D could prevent one-half of the cases of ...
Introduction: According to the World Health Organization, patient education mainly deals with chronic diseases and conditions which require self care. We know that this practice is still emerging and it is therefore interesting to observe the amount of international research produced in this field during the last years. Objective: We have analysed the quantitative evolution of scientific papers devoted to patient education (PE) over a 10 years period (1999-2009). Methods: Fourty-one chronic diseases and conditions in 11 disciplines have been selected as being the most concerned with patient education (PE). The identification on Pubmed of the studies dealing with these diseases, published from 1999 to 2009, has been undertaken considering the total number of articles mentioning PE activities, the distribution and the evolution in time of PE studies in those disciplines and chronic diseases, the types of publications (reviews, randomized control trials, meta-analyses) on PE. Results: We have ...
This study supports the recommendations by Cochrane Collaboration to prioritize MEDLINE, EMBASE and CENTRAL as the basic databases for literature search to locate RCTs in the musculoskeletal area. Secondly, this study indicates that besides MEDLINE, EMBASE and CENTRAL a literature search to locate RCTs in the musculoskeletal area could also consider SCOPUS and CINAHL. Finally, this study indicates that even with the addition search of 10 other often used databases median recall is not improved noticeably.. Thirteen different databases were not enough to identify all relevant references. Searching MEDLINE, EMBASE and CENTRAL retrieved 88.9%, and searches in 10 additional databases increased the median recall by only 2 percentage point. Thus, results from this study could be interpreted, as an indication that searching databases is not sufficient to identify all relevant references and that other sources must be included in the literature search in order to achieve a larger recall. This study does ...
Systematic reviews and meta-analyses are the best approaches available for summarizing the available evidence concerning the efficacy of therapies. Although the renal field has been slow to use these techniques, they are being used increasingly. In March 1997, the Cochrane Renal Group was formed, and this group aims to produce and maintain up to date systematic reviews of the evidence on the effectiveness of therapies used to treat patients with renal diseases. This group is part of the Cochrane Collaboration which is an international structure grouping collaborators together, with the aim of preparing, maintaining and disseminating systematic reviews of the effects of health care in all areas of medicine.. ...
To our knowledge, this is the first systematic review with cohort analysis and meta-analysis that has evaluated the role of WHO group 5 drugs in the treatment of fluoroquinolone-resistant MDR-TB and XDR-TB and with emphasis on the strength of association rather than statistical significance. We have systematically collected individual patient data from 20 articles in English to assemble a cohort of 194 fluoroquinolone-resistant MDR-TB patients treated with WHO group 5 drugs. Statistical analyses showed neither between-study heterogeneity nor publication bias. Both cohort analysis using robust Poisson regression models and meta-analysis using random-effects models showed that use of linezolid substantially and significantly increased the probability of favorable outcome by 50% to 60%. Defining clinically significant improvement by risk ratios ≥ 1.2 or ≤ 0.9, neither cohort analysis nor meta-analysis demonstrated any add-on benefit from the use of the other group 5 drugs (high-dose isoniazid, ...
Whether PWA increases risk of infection or severe outcomes from COVID-19 remains unclear. There is no consensus from systematic reviews, and high quality primary studies report conflicting results in some areas. Within PWA with COVID-19, people with co-morbid COPD and people with non-allergic asthma appear more vulnerable to worse outcomes. Older age and non-white ethnicity also appear to confer greater risk within PWA, as would be expected from data from the general population. Data on asthma medication use is difficult to interpret due to inconsistent findings across primary studies and possible confounding/co-linearity between asthma severity and medication prescribed, though the largest study of its type found that ICS use was associated with higher mortality risk in PWA.(22) Further primary studies and comprehensive meta-analyses are needed.. As well as - and perhaps linked to- the conflicting and imprecise results noted above, there a number of other important limitations to evidence in ...
Although recent meta-analyses of the HIV prevention intervention literature have demonstrated that behavioral interventions reduce sexual risk-taking among men who have sex with men (MSM), interventions for not-in-treatment substance using MSM are lacking. Consequently, and based upon overwhelming evidence that substance use is a primary driver of HIV infection among urban MSM, public health authorities have identified the development of efficacious interventions for substance using MSM as a concern of the highest priority. The proposed study aims to test a new intervention based upon psychological empowerment theory that, in preliminary field tests, produced high levels of acceptability and participation, as well as large reductions in sexual risks and substance use, among a sample of ethnically-diverse, high risk, substance using, HIV+ and -negative MSM. The intervention to be tested is based upon a theory of MSM health risk behaviors that posits that urban gay fast lane subcultures present ...
Although recent meta-analyses of the HIV prevention intervention literature have demonstrated that behavioral interventions reduce sexual risk-taking among men who have sex with men (MSM), interventions for not-in-treatment substance using MSM are lacking. Consequently, and based upon overwhelming evidence that substance use is a primary driver of HIV infection among urban MSM, public health authorities have identified the development of efficacious interventions for substance using MSM as a concern of the highest priority. The proposed study aims to test a new intervention based upon psychological empowerment theory that, in preliminary field tests, produced high levels of acceptability and participation, as well as large reductions in sexual risks and substance use, among a sample of ethnically-diverse, high risk, substance using, HIV+ and -negative MSM. The intervention to be tested is based upon a theory of MSM health risk behaviors that posits that urban gay fast lane subcultures present ...
Lithium has already shown value as an augmentation agent in Major Depression: in recent meta-analyses, augmentation with lithium was nearly 3 times more likely to produce a response than placebo.7,8 Forty percent showed response versus 14.4% in the placebo group, for a number needed to treat (NNT) of 5: youd need to treat 5 patients with lithium to see an effect of statistical magnitude; a less pronounced effect could be seen in even fewer patients.7 True, the antidepressants in these studies were mostly tricyclics, though 3 of 9 studies used SRIs8; do we have to wait for yet more studies with newer antidepressants? I think the Finnish population data, while they do not specify an NNT, are compelling-especially given the size of the effect seen (50% lower rehospitalization rate). As advocated in the most recent review,9 if my patient was hospitalized with severe depression, and there were no contraindications, shed likely leave on lithium-regardless of how bipolar she is ...
Abnormal β-amyloid (Aβ) levels were found in patients with Down syndrome (DS). However, Aβ levels in patients with DS and DS with dementia (DSD) vary considerably across studies. Therefore, we performed a systematic literature review and quantitatively summarized the clinical Aβ data on the cerebrospinal fluid (CSF) and blood of patients with DS and those with DSD using a meta-analytical technique. We performed a systematic search of the PubMed and Web of Science and identified 27 studies for inclusion in the meta-analysis. Random-effects meta-analysis indicated that the levels of blood Aβ1-40 and Aβ1-42 were significantly elevated in patients with DS compared with those in healthy control (HC) subjects. In contrast, there were no significant differences between patients with DS and those with DSD in the blood Aβ1-40 and Aβ1-42 levels. The CSF Aβ1-42 levels were significantly decreased in
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Contains a new chapter on microcirculation The already existing chapters have been rearranged and updated on the basis of the most recent meta-analyses
Multilevel network meta-regression for population adjustment based on individual and aggregate level data. Abstract: Standard network meta-analysis (NMA) and indirect comparisons combine aggregate data (AgD) from multiple studies on treatments of interest, assuming that any effect modifiers are balanced across populations. We can relax this assumption if individual patient data (IPD) are available from all studies by fitting an IPD meta-regression. However, in many cases IPD are only available from a subset of studies. In the simplest scenario, IPD are available for an AB study but only AgD for an AC study. Methods such as Matching Adjusted Indirect Comparison (MAIC) create a population-adjusted indirect comparison between treatments B and C. However, the resulting comparison is only valid in the AC population without additional assumptions, and the methods cannot be extended to larger treatment networks. Meta-regression-based approaches can be used in larger networks. However, these typically ...
This study provides evidence that the combined use of RAS inhibitors and statins may be associated with greater anticancer effects than use of either class of drugs in isolation. To explain this phenomenon, our animal data indicated that RAS blockade prevented the development of renal cell carcinoma in UNX rats via normalizing the expression of the HMGCR and IGF-1 signaling pathways.. The risk associations of statin use and cancer remain controversial. In epidemiological studies, the use of statins was associated with a large relative risk reduction for cancer (37). Conversely, nearly all meta-analyses of clinical trials (13,38) showed that statins have a neutral effect on incidence of cancer. However, results from meta-analyses are often inconclusive because of heterogeneity of study design, clinical profile of patient cohorts, different definitions for outcome measures, and quality of data. This statement is illustrated by the marked variations in cancer incidence ranging from 0.2 to 6.3% in ...
BioScience Laboratories, Inc. has always been capable in the realm of bio-statistics, and now we offer a new service: meta-analysis. Meta-analysis is the process of integrating the data from multiple individual studies performed by different technicians at different times at different laboratories into one unified study.. By using meta-analysis, you can have the various non-FDA studies performed on your product integrated into one study to make sense of the results. This is important, for example, when one researcher finds your product to be very good, and another finds it to be not acceptable. Instead of favoring one researcher and discounting the other, meta-analysis integrates all the studies results into one final result.. For FDA studies, you likely will have performed more than one study on your product. Perhaps two studies were done, one pivotal and the other, confirmatory. Meta-analysis can integrate the results from these for inclusion in your FDA submission packet.. To learn more ...
Due to the rapid spread of coronavirus disease 2019 (COVID-19) worldwide, it is necessary to ascertain essential immune inflammatory parameters that describe the severity of the disease and provide guidance for treatment. We performed network meta-analyses to determine differences in blood cells, lymphocyte subsets, and cytokines in COVID-19 patients with different clinical stages. Databases were systematically searched to May 2, 2020, and updated on June 1, 2020. Network meta-analyses were conducted via Stata 15.0, and the mean difference (MD) and its 95% CI were used as the effect values of the pooled analysis. Seventy-one studies were included involving 8647 COVID-19 patients, White blood cell (WBC), neutrophil (NEUT), IL-6, and IL-10 counts increased significantly with worsening of the COVID-19, while lymphocyte (LYM) counts decreased. The levels of platelet (PLT), CD3+, CD4+, CD8+, and CD19+ cells in severe and critical patients were significantly lower than those in mild patients. IL-1β count was
The heterogeneity test identified no significant cross-study heterogeneity, and the results of cumulative meta-analysis, sensitivity analysis, and the publication bias test verified the reliability of our study ...
Health,... NOVATO Calif. Sept. 27 /- BioMarinPharma... This meta-analysis stresses the importance of early and continuous Ph...Highlights from the meta-analysis are summarized below: ...-- Significant proportional correlations were found during critical/...,Meta-Analysis,of,Blood,Phe,Levels,and,Clinical,Outcomes,in,PKU,Published,medicine,medical news today,latest medical news,medical newsletters,current medical news,latest medicine news