In the article by Zoch and coworkers1 on short- and long-term survival after cardiopulmonary resuscitation, the authors describe a single center's experience with resuscitation from December 1983 through November 1991. While this article adds to the body of knowledge on the rate of survival after discharge to home, it "shorted" the prediction of in-hospital survival. Like most retrospective studies of prospectively collected data, the greatest threat to validity is the information that was not recorded or analyzed.
McCullough PA, Sandberg KR, Thompson RJ. Predicting Outcomes After Cardiopulmonary Resuscitation. Arch Intern Med. 2001;161(4):615-616. doi: