Objective: We investigated the epidemiology of sudden infant death syndrome (SIDS) in the Tyrol before and after an intervention campaign.
Patients and methods: Descriptive characteristics and risk factors of SIDS before the campaign were assessed in a retrospective case-control study (1984 to 1994). In April 1994 a country-wide information campaign on modifiable risk behaviours was initiated. Thereafter we prospectively collected data on child care practices four to six weeks after birth for all infants born in the Tyrol (participation rate 72%; n = 28,361) and evaluated new SIDS cases (1994 to 1998). For this purpose two questionnaires were used, one with 96 items for the evaluation of all SIDS cases and assessment of child care practices before 1994, and the other with 24 items for prospective data collection.
Results: The incidence of SIDS decreased from 1.83 (mean incidence, 1984-1994) to 0.4/1000 live births immediately after the campaign and remained low until 1998. The frequency of maternal smoking during pregnancy declined (22.9% vs. 14.5%, p < 0.01), as did the prevalence of the prone sleeping position (53.7% vs. 5.4%, p < 0.001) and of non-breastfeeding (21.3% vs. 6.7%, p < 0.001). All these variables were prominent risk factors for SIDS before the campaign and remained significant thereafter. On account of the markedly reduced prevalence of the prone sleeping position, smoking became the most common SIDS risk factor. The prevalence of sleeping on the side significantly increased (5.1% vs. 36.4%, p < 0.001) and the social status of mothers of SIDS infants tended to be lower than that before the campaign. The clear winter preponderance of SIDS which was evident before the campaign disappeared, or was even reversed.
Conclusions: Our study documents the long-term efficacy of a low-cost intervention campaign by way of health education. Further efforts must be directed toward lower social classes, thereby focusing on maternal smoking and avoidance of the side sleeping position.