nice_sampsi_cc: calculate sample size

In simonthelwall/nicethings: Nicely formats things for printing inline in Rmarkdown documents and other nice things

calculate sample size

Description

Returns the total number of observations required in a case control study. Uses the formulae on page 420 of Kirkwood and Sterne, 2nd Ed.

Usage

nice_sampsi_cc(pi_0, or, power, alpha, ratio = 1)

Arguments

pi_0	Proportion of controls exposed (0-1)
or	Minimum odds ratio to be detected
power	The power required (0-100%)
alpha	The alpha to be detected (0-100%)
ratio	Ratio of controls to cases

Details

It should be noted that there is an error on p422 that is corrected here: https://higheredbcs.wiley.com/legacy/college/kirkwood/0865428719/updates/updates.htm The error is in the last line of step 3, where the print states 2.2769/0.17^2 = 179.4 The correction is 2.2769^2/0.17^2 = 179.4

Examples

# Example 35.4, page 419 and 422 of Kirkwood and Sterne, 2nd Ed
# This gives a slightly lower result than Kirkwood and Sterne due to rounding.

nice_sampsi_cc(pi_0 = 0.4, or = 2, power = 90, alpha = 5)

simonthelwall/nicethings documentation built on Feb. 27, 2023, 3:15 p.m.