Patient Readmission: Subsequent admissions of a patient to a hospital or other health care institution for treatment.Patient Discharge: The administrative process of discharging the patient, alive or dead, from hospitals or other health facilities.Length of Stay: The period of confinement of a patient to a hospital or other health facility.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)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.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.Diagnosis-Related Groups: A system for classifying patient care by relating common characteristics such as diagnosis, treatment, and age to an expected consumption of hospital resources and length of stay. Its purpose is to provide a framework for specifying case mix and to reduce hospital costs and reimbursements and it forms the cornerstone of the prospective payment system.Hospital Costs: The expenses incurred by a hospital in providing care. The hospital costs attributed to a particular patient care episode include the direct costs plus an appropriate proportion of the overhead for administration, personnel, building maintenance, equipment, etc. Hospital costs are one of the factors which determine HOSPITAL CHARGES (the price the hospital sets for its services).Hospitalists: Physicians who are employed to work exclusively in hospital settings, primarily for managed care organizations. They are the attending or primary responsible physician for the patient during hospitalization.Hospitalization: The confinement of a patient in a hospital.Patient Acuity: An assessment of a patient's illness, its chronicity, severity, and other qualitative aspects.Sialometaplasia, Necrotizing: A benign, inflammatory, variably ulcerated, occasionally bilateral, self-healing lesion of the minor salivary glands that is often confused clinically and histologically with carcinoma.Aftercare: The care and treatment of a convalescent patient, especially that of a patient after surgery.United StatesQuality of Health Care: The levels of excellence which characterize the health service or health care provided based on accepted standards of quality.Quality Indicators, Health Care: Norms, criteria, standards, and other direct qualitative and quantitative measures used in determining the quality of health care.Hospital Mortality: A vital statistic measuring or recording the rate of death from any cause in hospitalized populations.Outcome and Process Assessment (Health Care): Evaluation procedures that focus on both the outcome or status (OUTCOMES ASSESSMENT) of the patient at the end of an episode of care - presence of symptoms, level of activity, and mortality; and the process (ASSESSMENT, PROCESS) - what is done for the patient diagnostically and therapeutically.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Outcome Assessment (Health Care): Research aimed at assessing the quality and effectiveness of health care as measured by the attainment of a specified end result or outcome. Measures include parameters such as improved health, lowered morbidity or mortality, and improvement of abnormal states (such as elevated blood pressure).Hospitals, Psychiatric: Special hospitals which provide care to the mentally ill patient.Insurance Claim Review: Review of claims by insurance companies to determine liability and amount of payment for various services. The review may also include determination of eligibility of the claimant or beneficiary or of the provider of the benefit; determination that the benefit is covered or not payable under another policy; or determination that the service was necessary and of reasonable cost and quality.Continuity of Patient Care: Health care provided on a continuing basis from the initial contact, following the patient through all phases of medical care.Risk Adjustment: The use of severity-of-illness measures, such as age, to estimate the risk (measurable or predictable chance of loss, injury or death) to which a patient is subject before receiving some health care intervention. This adjustment allows comparison of performance and quality across organizations, practitioners, and communities. (from JCAHO, Lexikon, 1994)Time Factors: Elements of limited time intervals, contributing to particular results or situations.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.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Patient Admission: The process of accepting patients. The concept includes patients accepted for medical and nursing care in a hospital or other health care institution.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.Multivariate Analysis: A set of techniques used when variation in several variables has to be studied simultaneously. In statistics, multivariate analysis is interpreted as any analytic method that allows simultaneous study of two or more dependent variables.Inpatients: Persons admitted to health facilities which provide board and room, for the purpose of observation, care, diagnosis or treatment.Hospitals, Teaching: Hospitals engaged in educational and research programs, as well as providing medical care to the patients.Emergencies: Situations or conditions requiring immediate intervention to avoid serious adverse results.Hospitals, Community: Institutions with permanent facilities and organized medical staff which provide the full range of hospital services primarily to a neighborhood area.Medication Reconciliation: The formal process of obtaining a complete and accurate list of each patient's current home medications including name, dosage, frequency, and route of administration, and comparing admission, transfer, and/or discharge medication orders to that list. The reconciliation is done to avoid medication errors.Hospitals, Veterans: Hospitals providing medical care to veterans of wars.Critical Pathways: Schedules of medical and nursing procedures, including diagnostic tests, medications, and consultations designed to effect an efficient, coordinated program of treatment. (From Mosby's Medical, Nursing & Allied Health Dictionary, 4th ed)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.Hospitals, Pediatric: Special hospitals which provide care for ill children.Ambulatory Surgical Procedures: Surgery performed on an outpatient basis. It may be hospital-based or performed in an office or surgicenter.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Pneumonia: Infection of the lung often accompanied by inflammation.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Emergency Service, Hospital: Hospital department responsible for the administration and provision of immediate medical or surgical care to the emergency patient.American Hospital Association: A professional society in the United States whose membership is composed of hospitals.Acute Disease: Disease having a short and relatively severe course.Myocardial Infarction: NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).