What is the leading cause of infant mortality? A note on the interpretation of official statistics

Objectives. According to vital statistics reports, congenital malformation is the leading cause of infant death in the United States and accounts for a much greater proportion of infant mortality than does premature birth. The purpose of this study was to examine the potential underestimation of prematurity-related mortality in current vital statistics reports. Methods. National mortality data from 1985, 1991, and 1996 were analyzed. Results. The official statistics significantly understate the role of prematurity-related mortality. An alternative etiology-based classification designates prematurity as the underlying cause in approximately one third of all infant deaths. Conclusions. Although no single scheme is suitable for every objective, analysts and policymakers should recognize the degree to which technical classification practices can influence the apparent importance of various causes of death.