Risk factors for SIDS in Japan: a record-linkage study based on vital statistics.

This study examines the effect of items as reported on birth certificates on sudden infant death. We linked infant death certificates with birth certificates for the infants born in 1989 to residents of the Tohoku, Tokai and Kyushu regions in Japan (n = 409,679), that is, about one-third of the infants born in Japan that year. The mortality rate from sudden infant death, including 88 deaths from sudden infant death syndrome (SIDS) and 17 deaths from instantaneous death, was 25.6 per 100,000 live births. Elevated risk of sudden infant death was associated with low birthweight, late birth order, illegitimacy, male gender and young maternal age. These results correspond to previous studies from Western countries, suggesting a similar pattern for SIDS in Japan.