Müller-Nordhorn J, Schneider A, Grittner U, et al. - This study was undertaken to explore international time trends in sudden unexpected infant death, 1969–2012. The number of deaths and live births (1969–2012) was provided by the National Statistical Offices of 52 countries. Researchers estimated infant mortality rates per 1000 live births for sudden unexpected infant death (SUID), SIDS, and all-cause mortality. A hierarchical cluster analysis was conducted to distinguish clusters of time trends for SUID and SIDS, including all-cause infant mortality. In SUID, the country-specific time trends varied considerably. The evidence suggested that identification of country-clusters may promote research into how changes in sleep position, smoking, immunization, or other factors are related to the findings.