In summary, the performance of the Liang-Zeger sandwich estimator suffers as the sample sizes dropped below 50 subjects, and the outcome prevalence values were less than 30%. This drop off in performance is further exacerbated at the lower outcome prevalence values and smaller sample sizes. Under these extreme conditions, the Rogers and Pan estimators would be good choices for variance estimators followed by any of the two estimators proposed by Morel. The Mancl and DeRouen estimator outperformed the Liang-Zeger estimator under all outcome prevalence values as the sample size dropped below 50 subjects. With outcome prevalence valuess of 30% or higher and sample sizes less than 50 subjects, the Liang-Zeger estimator still consistently underestimated the coefficient variances even in these nominal conditions.
