Weaknesses of goodness-of-fit tests for evaluating propensity score models: the case of the omitted confounder.
Weitzen S, Lapane KL, Toledano AY, Hume AL, Mor V. Weaknesses of goodness-of-fit tests for evaluating propensity score models: the case of the omitted confounder. Pharmacoepidemiol Drug Saf. 2005 Apr; 14(4):227-38.