✦ LIBER ✦

Sample Size Requirements in Studies of the Etiologic Fraction

✍ Scribed by Dr. Judith A. Smith; Prof. R. B. McHugh

Book ID: 102759129
Publisher: John Wiley and Sons
Year: 1988
Tongue: English
Weight: 740 KB
Volume: 30
Category: Article
ISSN: 0323-3847
DOI: 10.1002/bimj.4710300211

No coin nor oath required. For personal study only.

✦ Synopsis

This paper outlines methods of determining sample size for epidemiologic research in studiea of the etiologic fraction. The basic model with a dichotomous disease and a single dichotomous expo aure factor is considered. To determine sample size. the reeearcher must specify: the magnitude of the etiologic fraction E to be detected SB statistically significant, thelevel of significancea, the power 1 -b of the tat, p the proportion of the population exposed to the risk factor and R t h e proportion of the population with the disease. Sample size formulas and tables are presented for the case-control, cohort and cross-sectional designs. Optimal allocation considerations are examined to minimirte cost for a epeeified. power. Extensive use is made of Walter's results concerning the asymptotic variance of the maximum likelihood estimator of the etiologic fraction for the three epidemiologic study designs. K e y tmds; Case-control design ; Cohort design ; Cross-sectional design ; Etiologic fraction ; Sample size.

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