Epidemiological factors in postneonatal mortality in New Zealand.

Nine hundred and sixty-two postneonatal deaths for 1981-83 were matched to their birth registration forms. Deaths were divided into three categories, sudden infant death syndrome (SIDS) 65.4%, other preventable, 12.8%, and nonpreventable causes, 21.8%, to determine the rates of death as related to known and available risk factors. The risk factor profile for other preventable causes and SIDS was similar, the only exceptions being that other preventable causes showed no north-south gradient and had a higher incidence in the neonatal period (31.2% v 4.7% for SIDS). The most important risk factors for other preventable causes were found to be the mother being Maori (RR 4.35, CI 3.12-6.06), having a low birth weight infant (RR 3.56, CI 2.07-6.13) and being unmarried (RR 3.45, CI 2.47-4.82). These risk factors point to the possibility of selectively targeting of interventions both prenatally as well as postnatally for those who are at high risk.