Lewis makes an important point that the apparent failure of cardiopulmonary resuscitation (CPR) outcome predictors to predict CPR outcome in the study by Rosenberg et al1 may have been due to a bias that resulted from the proper application of DNA orders that, in turn, resulted in the exclusion of those least likely to survive among the attempted CPR population. If this were the case, we would hope that Rosenberg et al would enlighten us as to the manner in which this selection was accomplished. There is no mention, however, by Rosenberg et al that any unusual application of the do-not-resuscitate process was in place at either one or both of the hospitals examined. Indeed, there was a rather wide variation from hospital A to hospital B in survival of resuscitation (Table 21) and in survival to discharge (Table 31) in a number of the subgroups analyzed.
McIntyre KM. Cardiopulmonary Resuscitation Survival-Reply. Arch Intern Med. 1994;154(2):227. doi:10.1001/archinte.1994.00420020151021