The development of a model for predicting infants at high risk of sudden infant death syndrome in Tasmania.

A statutory 'Notification of Birth' form, containing obstetric and perinatal information, has been routinely collected for Tasmanian deliveries since 1974. For the period 1980 to 1984, birth notification data was collected for over 99% of Tasmanian deliveries. This data was examined for the 130 cases of sudden infant death syndrome (SIDS) that occurred from 1980 to 1984 and for 610 controls. It was then used to construct an at-birth scoring system to predict infants at higher risk of SIDS in the postneonatal period. A predictive model of the relative risk of SIDS was developed by fitting a binomial/logistic generalised linear model to the binary 1980-1984 case control data with birth variables used as predictors. The final predictive model contained five variables (maternal age, infant sex, birth weight, month of birth and feeding practice) and had a sensitivity of 62% and specificity of 73%. The model was then tested on independent birth cohorts from 1985 and 1986 and found to have a sensitivity of 47% and specificity of 77%. The risk of SIDS in the group of infants classified as high risk was 7.9 per 1000 live births and in the group at low risk it was 2.5 per 1000 live births. In addition, the model predicted 74% of neonatal deaths occurring during these 2 years. This compares well with other predictive models developed elsewhere. The predictive model will be used to identify infants at high risk for SIDS in a prospective cohort study.