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Although in classical case–control studies, it remains true that the odds ratio can only approximate the relative risk in the case of rare diseases, there is a number of other types of studies (case–cohort, nested case–control, cohort studies) in which it was later shown that the odds ratio of exposure can be used to estimate the relative ...
Recall bias is of particular concern in retrospective studies that use a case-control design to investigate the etiology of a disease or psychiatric condition. [ 3 ] [ 4 ] [ 5 ] For example, in studies of risk factors for breast cancer , women who have had the disease may search their memories more thoroughly than members of the unaffected ...
Psychiatrists have been involved in human rights abuses in states across the world when the definitions of mental disease were expanded to include political disobedience. [ 22 ] : 6 In the period from the 1960s to 1986, abuse of psychiatry for political purposes was reported to be systematic in the Soviet Union and other Eastern European countries.
For example, recall bias is likely to occur in cross-sectional or case-control studies where subjects are asked to recall exposure to risk factors. Subjects with the relevant condition (e.g. breast cancer) may be more likely to recall the relevant exposures that they had undergone (e.g. hormone replacement therapy) than subjects who don't have ...
Both the relative risk and odds ratio are relevant in retrospective cohort studies, but only the odds ratio can be used in case-control studies. Although most case-control studies are retrospective, they can also be prospective when the researcher still enrolls participants based on the occurrence of a disease as new cases occur. [citation needed]
AZT trials conducted on HIV-positive African subjects by U.S. physicians and the University of Zimbabwe were performed without proper informed consent. [4] The United States began testing AZT treatments in Africa in 1994, through projects funded by the Centers for Disease Control (CDC), the World Health Organization (WHO) and the National Institutes of Health (NIH).
The nested case–control study can be analyzed using methods for missing covariates. [2] The NCC design is often used when the exposure of interest is difficult or expensive to obtain and when the outcome is rare. By utilizing data previously collected from a large cohort study, the time and cost of beginning a new case–control study is avoided.
Systemic bias is the inherent tendency of a process to support particular outcomes. The term generally refers to human systems such as institutions. Systemic bias is related to and overlaps conceptually with institutional bias and structural bias, and the terms are often used interchangeably.