To the Editor.
—Dr Lurie and colleagues1 conclude that active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) appears to be more effective than standard CPR in certain subsets under study. This statistical inference is dependent on matching baseline characteristics as presented in their Table 1.In prehospital nontraumatic cardiac arrest, a sudden reversible cardiac miscue based on myocardial ischemia or a small myocardial infarction in an otherwise healthy person is the most likely condition to have a successful CPR outcome. On the other hand, if the pathway to arrest is pulmonary embolus, massive cerebral vascular accident, aortic dissection, or sepsis, then the probability of a successful outcome is much less. The authors match the previous cardiac history in both groups (62%); however, previous cardiac history alone, without the present clinical history, is not sufficient to give meaning to the statistical analysis. This is particularly true for the subgroup analysis of those
Mazziotti A. Active Compression-Decompression CPR. JAMA. 1994;272(17):1325-1326. doi:10.1001/jama.1994.03520170035022