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Hierarchy Of Evidence
A hierarchy of evidence (or levels of evidence) is a heuristic used to rank the relative strength of results obtained from scientific research. There is broad agreement on the relative strength of large-scale, epidemiological studies. More than 80 different hierarchies have been proposed for assessing medical evidence. The design of the study (such as a case report for an individual patient or a blinded randomized controlled trial) and the endpoints measured (such as survival or quality of life) affect the strength of the evidence. In clinical research, the best evidence for treatment efficacy is mainly from meta-analyses of randomized controlled trials (RCTs). Systematic reviews of completed, high-quality randomized controlled trials – such as those published by the Cochrane Collaboration – rank the same as systematic review of completed high-quality observational studies in regard to the study of side effects. Evidence hierarchies are often applied in evidence-based practic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heuristic
A heuristic (; ), or heuristic technique, is any approach to problem solving or self-discovery that employs a practical method that is not guaranteed to be optimal, perfect, or rational, but is nevertheless sufficient for reaching an immediate, short-term goal or approximation. Where finding an optimal solution is impossible or impractical, heuristic methods can be used to speed up the process of finding a satisfactory solution. Heuristics can be mental shortcuts that ease the cognitive load of making a decision. Examples that employ heuristics include using trial and error, a rule of thumb or an educated guess. Heuristics are the strategies derived from previous experiences with similar problems. These strategies depend on using readily accessible, though loosely applicable, information to control problem solving in human beings, machines and abstract issues. When an individual applies a heuristic in practice, it generally performs as expected. However it can alternativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Study Design
Clinical study design is the formulation of trials and experiments, as well as observational studies in medical, clinical and other types of research (e.g., epidemiological) involving human beings. The goal of a clinical study is to assess the safety, efficacy, and / or the mechanism of action of an investigational medicinal product (IMP) or procedure, or new drug or device that is in development, but potentially not yet approved by a health authority (e.g. Food and Drug Administration). It can also be to investigate a drug, device or procedure that has already been approved but is still in need of further investigation, typically with respect to long-term effects or cost-effectiveness. Some of the considerations here are shared under the more general topic of design of experiments but there can be others, in particular related to patient confidentiality and ethics. Outline of types of designs for clinical studies Treatment studies * Randomized controlled trial ** Blind trial ** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cohort Study
A cohort study is a particular form of longitudinal study that samples a cohort (a group of people who share a defining characteristic, typically those who experienced a common event in a selected period, such as birth or graduation), performing a cross-section at intervals through time. It is a type of panel study where the individuals in the panel share a common characteristic. Cohort studies represent one of the fundamental designs of epidemiology which are used in research in the fields of medicine, pharmacy, nursing, psychology, social science, and in any field reliant on 'difficult to reach' answers that are based on evidence (statistics). In medicine for instance, while clinical trials are used primarily for assessing the safety of newly developed pharmaceuticals before they are approved for sale, epidemiological analysis on how risk factors affect the incidence of diseases is often used to identify the causes of diseases in the first place, and to help provide pre-clinica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Randomization
Randomization is the process of making something random. Randomization is not haphazard; instead, a random process is a sequence of random variables describing a process whose outcomes do not follow a deterministic pattern, but follow an evolution described by probability distributions. For example, a random sample of individuals from a population refers to a sample where every individual has a known probability of being sampled. This would be contrasted with nonprobability sampling where arbitrary individuals are selected. In various contexts, randomization may involve: * generating a random permutation of a sequence (such as when shuffling cards); * selecting a random sample of a population (important in statistical sampling); * allocating experimental units via random assignment to a treatment or control condition; * generating random numbers (random number generation); or * transforming a data stream (such as when using a scrambler in telecommunications). Applications Rando ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Preventive Services Task Force
The United States Preventive Services Task Force (USPSTF) is "an independent panel of experts in primary care and prevention that systematically reviews the evidence of effectiveness and develops recommendations for clinical preventive services". The task force, a volunteer panel of primary care clinicians (including those from internal medicine, pediatrics, family medicine, obstetrics and gynecology, nursing, and psychology) with methodology experience including epidemiology, biostatistics, health services research, decision sciences, and health economics, is funded, staffed, and appointed by the U.S. Department of Health and Human Services' Agency for Healthcare Research and Quality. Intent The USPSTF evaluates scientific evidence to determine whether medical screenings, counseling, and preventive medications work for adults and children who have no symptoms. Methods The methods of evidence synthesis used by the Task Force have been described in detail. In 2007, their methods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Case Control Study
Case or CASE may refer to: Containers * Case (goods), a package of related merchandise * Cartridge case A cartridge or a round is a type of pre-assembled firearm ammunition packaging a projectile (bullet, shot, or slug), a propellant substance (usually either smokeless powder or black powder) and an ignition device (primer) within a metallic, ... or casing, a firearm cartridge component * Bookcase, a piece of furniture used to store books * Briefcase or attaché case, a narrow box to carry paperwork * Computer case, the enclosure for a PC's main components * Keep case, DVD or CD packaging * Pencil case * Phone case, protective or vanity accessory for mobile phones ** Battery charger#Battery cases, Battery case * Road case or flight case, for fragile equipment in transit * Shipping container or packing case * Suitcase, a large luggage box * Type case, a compartmentalized wooden box for letterpress typesetting Places * Case, Laclede County, Missouri * Case, Warren County, M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cohort Study
A cohort study is a particular form of longitudinal study that samples a cohort (a group of people who share a defining characteristic, typically those who experienced a common event in a selected period, such as birth or graduation), performing a cross-section at intervals through time. It is a type of panel study where the individuals in the panel share a common characteristic. Cohort studies represent one of the fundamental designs of epidemiology which are used in research in the fields of medicine, pharmacy, nursing, psychology, social science, and in any field reliant on 'difficult to reach' answers that are based on evidence (statistics). In medicine for instance, while clinical trials are used primarily for assessing the safety of newly developed pharmaceuticals before they are approved for sale, epidemiological analysis on how risk factors affect the incidence of diseases is often used to identify the causes of diseases in the first place, and to help provide pre-clinica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Case Reports
In medicine, a case report is a detailed report of the symptoms, signs, diagnosis, treatment, and follow-up of an individual patient. Case reports may contain a demographic profile of the patient, but usually describe an unusual or novel occurrence. Some case reports also contain a literature review of other reported cases. Case reports are professional narratives that provide feedback on clinical practice guidelines and offer a framework for early signals of effectiveness, adverse events, and cost. They can be shared for medical, scientific, or educational purposes. Types Most case reports are on one of six topics: * An unexpected association between diseases or symptoms. * An unexpected event in the course of observing or treating a patient. * Findings that shed new light on the possible pathogenesis of a disease or an adverse effect. * Unique or rare features of a disease. * Unique therapeutic approaches. * A positional or quantitative variation of the anatomical structures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross-sectional Study
In medical research, social science, and biology, a cross-sectional study (also known as a cross-sectional analysis, transverse study, prevalence study) is a type of observational study that analyzes data from a population, or a representative subset, ''at a specific point in time''—that is, cross-sectional data. In economics, cross-sectional studies typically involve the use of cross-sectional regression, in order to sort out the existence and magnitude of causal effects of one independent variable upon a dependent variable of interest at a given point in time. They differ from time series analysis, in which the behavior of one or more economic aggregates is traced through time. In medical research, cross-sectional studies differ from case-control studies in that they aim to provide data on the entire population under study, whereas case-control studies typically include only individuals who have developed a specific condition and compare them with a matched sample, oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cohort Studies
A cohort study is a particular form of longitudinal study that samples a cohort (a group of people who share a defining characteristic, typically those who experienced a common event in a selected period, such as birth or graduation), performing a cross-section at intervals through time. It is a type of panel study where the individuals in the panel share a common characteristic. Cohort studies represent one of the fundamental designs of epidemiology which are used in research in the fields of medicine, pharmacy, nursing, psychology, social science, and in any field reliant on 'difficult to reach' answers that are based on evidence (statistics). In medicine for instance, while clinical trials are used primarily for assessing the safety of newly developed pharmaceuticals before they are approved for sale, epidemiological analysis on how risk factors affect the incidence of diseases is often used to identify the causes of diseases in the first place, and to help provide pre-clinica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |