Goldstein et al discuss sudden infant death syndrome (SIDS) in the context of overall postneonatal mortality (PNNM). However, their definition of SIDS is incorrect, and they make questionable choices in constructing composite groupings of unknown causes and circumstantial respiratory causes, which they combine with SIDS for a cumulative unexplained infant death composite. If they reread Willinger et al1 more closely they would see that “There was considerable discussion of whether two definitions should be drafted, one for administrative purposes to be used by medical examiners or coroners, and one for research [page 678].” To avoid confusion, Willinger et al agreed that a simple definition of SIDS would be drafted with accompanying statements to guide research scientists, which led to the upper cutoff of exactly 1 year of age; this cutoff was chosen because of the higher likelihood of false-positive SIDS cases occurring at age >1 year contaminating the actual SIDS cases >1 year of age. Indeed, they cited a Eunice Kennedy Shriver National Institute of Child Health and Human Development Collaborative SIDS Study in which 2% of the cases occurred at >1 year of age.
In their Table 1, Goldstein et al failed to include the International Classification of Diseases, 10th Revision, causes of PNNM from severe birth asphyxia (P21.0) and birth asphyxia, unspecified (P21.9), perhaps because they assumed birth asphyxia did not lead to PNNM. In addition, a new International Classification of Diseases, 10th Revision, code was introduced in 2006 for hypoxic-ischemic encephalopathy (P91.6) for cases that previously were coded as P21.9. These PNNM cases are highly relevant because they may be related to the intrinsic vulnerability of the neural abnormalities of the triple risk model (TRM) that the authors cite as a possible cause of SIDS. The TRM posits interactions between an underlying intrinsic vulnerability, a critical development period, and extrinsic factors in the infant’s environment. There is no critical development period (the “legal fiction” of a 12-month cutoff notwithstanding), as the full age distribution of SIDS extends from birth up to 3.5 years as modeled by a single equation.2 Also, SIDS cases do occur without any extrinsic risk factors, as reported for a sudden unexpected death of an apparently healthy child put to sleep supine and found dead in the identical supine position with face completely uncovered.3 If a lung culture had not been taken by Dr Sidney Farber (eponymous of Dr Goldstein's institution), the cause of death would have been given as “suffocation,ʺ4 and if the culture results were sepsis negative, it also would have been called “SIDS” today without any extrinsic factor present.5
Conflict of Interest: None declared
- Mage DT
- Brooks EG,
- Gill JR
- Copyright © 2016 by the American Academy of Pediatrics