[Sudden infant death syndrome: the times are changing]

Case-control studies of sudden infant death syndrome (SIDS) in the Netherlands have shown a number of important risk factors, including prone sleeping position, the use of a duvet, the use of sedating antihistamines, and bed-sharing with parents. After issuing preventive advice to avoid these risk factors, the SIDS mortality rate has decreased dramatically in the Netherlands, from 100 cases per 100,000 live births per year in the 1980s to 10-15 cases in recent years. Recent cohort studies of SIDS infants suggest that new risk factors are emerging. For example, SIDS now occurs increasingly while the infants are in day care. Such associations should be examined in case-control studies before preventive advice can be given. The Dutch SIDS risk-factor studies are an example of how epidemiologic studies can have a great impact on public health.