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. 1977 Apr;105(4):387-97.
doi: 10.1093/oxfordjournals.aje.a112395.

Determination of significant relative risks and optimal sampling procedures in prospective and retrospective comparative studies of various sizes

S D Walter

Determination of significant relative risks and optimal sampling procedures in prospective and retrospective comparative studies of various sizes

S D Walter. Am J Epidemiol. 1977 Apr.

Abstract

Methods are given for determining the relative risks which it is possible to demonstrate as statistically significant with given probability in prospective and retrospective studies of a particular size. Also considered is the ratio of the sample sizes in the two groups being compared which will provide the most precise estimate of relative risk for a given total sample size.

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