Estimates of statistical power (%) under the null hypothesis using the asymptotic distribution versus the permutation procedure, and elapsed computational times (in seconds) under different simulation scenarios.

Estimates were computed for 1,000 and 10,000 simulated tables (ST), number of cases equal to number of controls, and level of significance α = 0.05 (therefore, estimated power values should be close to 5%). Time estimates were obtained using an Intel® Core™ I5 3.1 GHz. These values were averaged over ten simulations each.