Sample Size for Matched Case-control Studies


Menu location: Analysis_Sample Size_Matched Case-Control.


This function gives you the minimum sample size necessary to detect a true odds ratio OR with power POWER and a two sided type I error probability ALPHA. If you are using more than one control per case then this function also provides the reduction in sample size relative to a paired study that you can obtain using your number of controls per case (Dupont, 1988).


Information required


Practical issues


Technical validation

The estimated sample size n is calculated as (Dupont, 1990):

- where α = alpha, β = 1 - power, ψ = odds ratio, ϕ is the correlation coefficient for exposure between matched cases and controls, and Zp is the standard normal deviate for probability p. n is rounded up to the closest integer.