Immeasurable Time Bias in Observational Studies of Drug Effects on Mortality
نویسندگان
چکیده
منابع مشابه
Immeasurable time bias in observational studies of drug effects on mortality.
Observational studies suggesting that some drugs are effective at reducing mortality may have been subject to "immeasurable time bias" arising from the unidentified presence of hospitalizations when defining drug exposure with computerized health databases. The author illustrates the bias using a case-control study of 1,313 deaths and 1,313 controls selected from a cohort of 2,049 patients with...
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Observational studies suggesting that some drugs are effective at reducing mortality may have been subject to ‘‘immeasurable time bias’’ arising from the unidentified presence of hospitalizations when defining drug exposure with computerized health databases. The author illustrates the bias using a case-control study of 1,313 deaths and 1,313 controls selected from a cohort of 2,049 patients wi...
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BACKGROUND The use of decongestants during the second or third trimesters of pregnancy has been associated with a decreased risk of preterm delivery in two observational studies. This effect may have been subject to immortal time bias, a bias arising from the improper classification of exposure during follow-up. We illustrate this bias by repeating the studies using a different data source. M...
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Avoiding Bias in Observational Studies
T he randomized clinical trial is a well established and frequently used study design and is generally accepted as the gold standard (1). Nevertheless, many questions can only be answered with epidemiological observational studies, such as the influence of cigarette consumption on the development of lung cancer (2), the effects of sport, nutrition and overweight on cardiovascular diseases (3), ...
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ژورنال
عنوان ژورنال: American Journal of Epidemiology
سال: 2008
ISSN: 0002-9262,1476-6256
DOI: 10.1093/aje/kwn135