Relative risk is usually the parameter of interest in epidemiologic and medical studies.
In this paper, the author proposes a modified Poisson regression approach (i.e., Poisson
regression with a robust error variance) to estimate this effect measure directly.
A simple 2-by-2 table is used to justify the validity of this approach. Results from
a limited simulation study indicate that this approach is very reliable even with
total sample sizes as small as 100. The method is illustrated with two data sets.