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Population Attributable Fraction
In epidemiology, attributable risk or excess risk is a term synonymous to risk difference, that has also been used to denote attributable fraction among the exposed and attributable fraction for the population. See also * Population Impact Measures Population impact measures (PIMs) are biostatistical measures of risk and benefit used in epidemiological and public health research. They are used to describe the impact of health risks and benefits in a population, to inform health policy. Freq ... References {{Medical research studies Epidemiology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidemiology
Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population. It is a cornerstone of public health, and shapes policy decisions and evidence-based practice by identifying risk factors for disease and targets for preventive healthcare. Epidemiologists help with study design, collection, and statistical analysis of data, amend interpretation and dissemination of results (including peer review and occasional systematic review). Epidemiology has helped develop methodology used in clinical research, public health studies, and, to a lesser extent, basic research in the biological sciences. Major areas of epidemiological study include disease causation, transmission, outbreak investigation, disease surveillance, environmental epidemiology, forensic epidemiology, occupational epidemiology, screening, biomonitoring, and comparisons of treatment effects such as in c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Risk Difference
The risk difference (RD), excess risk, or attributable risk is the difference between the risk of an outcome in the exposed group and the unexposed group. It is computed as I_e - I_u, where I_eis the incidence in the exposed group, and I_u is the incidence in the unexposed group. If the risk of an outcome is increased by the exposure, the term absolute risk increase (ARI) is used, and computed as I_e - I_u. Equivalently, if the risk of an outcome is decreased by the exposure, the term absolute risk reduction (ARR) is used, and computed as I_u - I_e. The inverse of the absolute risk reduction is the number needed to treat, and the inverse of the absolute risk increase is the number needed to harm. Usage in reporting It is recommended to use absolute measurements, such as risk difference, alongside the relative measurements, when presenting the results of randomized controlled trials. Their utility can be illustrated by the following example of a hypothetical drug which reduces the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Attributable Fraction Among The Exposed
In epidemiology, attributable fraction among the exposed (AFe) is the proportion of incidents in the exposed group that are attributable to the risk factor. The term attributable risk percent among the exposed is used if the fraction is expressed as a percentage. It is calculated as AF_e = (I_e - I_u)/I_e = (RR - 1) / RR, where I_e is the incidence in the exposed group, I_u is the incidence in the unexposed group, and RR is the relative risk. It is used when an exposure increases the risk, as opposed to reducing it, in which case its symmetrical notion is preventable fraction among the unexposed. Synonyms Multiple synonyms of AFe are in use: attributable fraction, relative attributable risk, attributable proportion among the exposed, and attributable risk among the exposed. Similarly, attributable risk percent (ARP) is used as a synonym for the attributable risk percent among the exposed. In climatology, fraction of attributable risk (FAR) is used to denote a proportion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Attributable Fraction For The Population
In epidemiology, attributable fraction for the population (AFp) is the proportion of incidents in the population that are attributable to the risk factor. The term attributable risk percent for the population is used if the fraction is expressed as a percentage. It is calculated as AF_p = (I_p - I_u)/I_p, where I_p is the incidence in the population, and I_u is the incidence in the unexposed group. Equivalently it can be calculated as AF_p = \frac, where P_eis the exposed proportion of the population and RR is the relative risk not adjusted for confounders. It is used when an exposure increases the risk, as opposed to reducing it, in which case its symmetrical notion is preventable fraction for the population. Synonyms Multiple synonyms of the attributable fraction for the population are in use: attributable proportion for the population, population attributable proportion, Levin's attributable risk, population attributable risk, and population attributable fraction. Similarly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Impact Measures
Population impact measures (PIMs) are biostatistical measures of risk and benefit used in epidemiological and public health research. They are used to describe the impact of health risks and benefits in a population, to inform health policy. Frequently used measures of risk and benefit identified by Jerkel, Katz and Elmore, describe measures of risk difference (attributable risk), rate difference (often expressed as the odds ratio or relative risk), population attributable risk (PAR), and the relative risk reduction, which can be recalculated into a measure of ''absolute benefit'', called the number needed to treat. Population impact measures are an extension of these statistics, as they are measures of absolute risk at the population level, which are calculations of number of people in the population who are at risk to be harmed, or who will benefit from public health interventions. They are measures of absolute risk and benefit, producing numbers of people who will benefit fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
