https://www.selleckchem.com/pr....oducts/a-1155463.htm
We observed a difference in performance of matching methods in very small samples (N = 25-5 and in moderately small samples (N = 100-30. Our study showed that PSM performs better than other matching methods when number of exposed subjects is small, but the matching algorithm and the matching ratio should be considered carefully. We recommend using PSM with optimal algorithm and one-to-five matching ratio in very small samples, and PSM matching with any algorithm and one-to-one matching in moderately small samples.Cystine stones ar