Background: An intervention to reduce the prevalence of the prone sleeping position during infancy was implemented in Tasmania particularly from 1991 onward. The purpose of this report is to assess the impact of public health activities in promoting avoidance of the prone infant sleeping position among cohort study participants.
Methods: The prospective cohort study involved the one-fifth of Tasmanian live births who are assessed perinatally as being at higher risk for Sudden Infant Death Syndrome (SIDS). From 1 January 1988 until 30 April 1992, 5,403 infants participated in the hospital (4 days postnatal age) and home interviews (5 weeks postnatal age) (88% of eligible infants). After the finding that cohort infants who usually slept prone were at significantly greater risk for SIDS, additional questions on awareness and choice of infant sleep position were asked.
Results: The proportion of infants usually sleeping prone declined from 29.9% in the cohort prior to publication of the cohort findings (1 May 1988-30 April 1991) to 5.4% in the post publication cohort (1 May 1991-30 April 1992), RR = 0.18 (0.15, 0.22). Teenage motherhood was associated with non-awareness (RR = 2.39 (1.41, 3.24)) of an association between prone position and SIDS. After adjusting for maternal age, nonawareness remained positively associated with maternal smoking, maternal education (< Year 12), and paternal unemployment, while mothers who read books to prepare for the baby and who were married were more likely to be aware. In the period after the cohort study publication, the most common reasons given for the usual prone position were that the baby preferred that position and slept better.
Conclusion: Public health activities to reduce the prevalence of the prone sleeping position have had a significant impact, with a dramatic reduction in the proportion of cohort infants usually sleeping prone. The identification of characteristics of nonaware mothers and the reasons for choosing a particular sleeping position will be used to maintain and improve health education in this area.