Abstract

PIP: Epidemiologic methods were used to determine 1) the incidence of sudden unexpected infant deaths (SUD); 2) the sociomedical characteristics of victims; and 3) possible causes of the deaths. The survey population lived in 12 counties and 2 cities of Ontario. Deaths of all infants occurring from January 1, 1965-June 30, 1966 were studied and of these 88 were determined to be possible cases of SUD. Interviews were conducted with 66 families to determine 1) socioeconomic characteristics; 2) circumstances of the birth; 3) medical and developmental history of the child; and 4) the circumstances of the death. Initial analysis of the data yielded a statistically significant possibility that weather conditions are associated with the occurrence of these deaths and confirmatory studies were performed. In addition, the following epidemiological data were obtained: 1) 72.7% of the deaths occurred in infants under 4 months of age; 2) a significantly greater number of deaths occurred in December-March; 3) 27.3% of the infants died less than 1 hour after they were last seen alive; 4) 37.9% died from noon to midnight; 5) the mothers of the infants represented all levels of education; 6) prematurity, low birth weight, low maternal age, and smoking appeared to be associated with SUD; and 7) 84.8% of the infants had been exclusively bottle fed.