Analysis of the Effect of the “Back to Sleep” Campaign on Sudden Unexpected Death in One Year Olds

Abstract

Background: The mortality of sudden unexplained death (SUD), one major cause of infant death aged less than1year, was remarkably reduced by Back- to- Sleep campaign (BSC). A number of case of SUD have been reported to be found in patients age more than one year who sleep in prone position. Depending on this reports, it is suggested that prone sleeping position may be a risk factor of SUD even for children more than one year old. In order to confirm the effect of BSC for preventing child more than one year of age from SUD, the mortality of SUD before and after BSC conducted was investigated by each age group. Methods: The annual transition of SUD by age under 3 in Japan was surveyed before and after starting BSC. The number of live births and population according to age and the number of death classifications according to age were extracted by year from the demographic statistics published by the Ministry of Health, Labor and Welfare website in Japan. Incidence was calculated as the ratio of number of deaths to each age population of 1000 people. SUD mortality trends were analyzed using a moving average every three years. Findings: The SUD mortality of 1-year- old children and younger exhibited a similar trend where a dramatic reduction was recognized immediately after BSC was conducted and constantly decreased for 10 years. The mortality reduction ratio of both 1 year olds and victims younger than one year of age was about 45% for 10 years. Meanwhile, the SUD mortality of 2 years olds failed to exhibit significant trend. The annual SUD mortality of more than 1 year was more variable than that of younger infants. Interpretation: It is suspected that prone sleeping becomes a risk for SUD even for children over 1 year old in the presents of risk factors. A detailed epidemiological investigation should be performed to prevent SUD in child. Funding Statement: This study was supported by the Intramural Research Grants of Tokyo Metropolitan Tama-Hokubo Medical Center (grant number: TH17-8). Declaration of Interests: All authors have no conflicts of interest to disclose. Ethics Approval Statement: The research was conducted with the consent of the Ethics Committee of Tamahokubu Medical Center (Approval number: T 18-12).