Sudden infant death syndrome (SIDS) in Austria. Socioeconomic risk factors for postneonatal SIDS- and non-SIDS-mortality

Abstract

Objective: To examine and compare socioeconomic risk factors for SIDS and non-SIDS in postneonatal age in Austria. Methods: We conducted a population-based retrospective cohort study using the govermental linked birth and death certificate file for 1984 to 1993. Our studied population includes all single live-births surviving the neonatal period (n = 880 601). Postneonatal deaths (n = 2989) were divided into SIDS (ICD9 798.0; n = 1070) and all other causes of death (non-SIDS; n = 1919). Mortality rates were expressed as deaths per 1000 infants surviving the neonatal period. Crude and adjusted relative risks of death (RR) and 95 % confidence intervals (CI) were obtained by logistic regression analysis. Social risk factors, demographic risk factors, and birth weight were included as independent variables. Results: Social risk factors turned out to be closely associated both with SIDS and with non-SIDS-mortality. Concerning SIDS, women in the lowest educational group have a RR of 1.45 (CI = 1.16–1.81) compared to highly educated women. For non-SIDS the RR was 1.48 (CI = 1.26–1.74). Immigrant workers (women of Turkish and Ex-Yugoslavian origin) had a much lower risk for SIDS compared to Austrian mothers (RR = 0.33, CI = 0.24–0.47). Living in big cities was associated with a higher risk for SIDS (RR = 1.63, CI = 1.42–1.86), in contrast to a lower risk for non-SIDS (RR = 0.89, CI = 0.80–1.00). Conclusions: When controlling for demographic risk factors and birth weight, unfavourable social conditions still remain an important risk factor for SIDS and non-SIDS in postneonatal age. Attempts to improve these conditions should not be confined to SIDS, but they should be integrated into preventive programs aimed at reducing infant mortality in general.