SEASONALITY OF SUDDEN-INFANT-DEATH-SYNDROME IN MAINLAND BRITAIN AND IRELAND 1985-95

By the end of 1995 four years had passed since the dramatic fall in th e incidence of sudden infant death syndrome (SIDS:), following the ''b ack to sleep'' campaign. This time lag permitted a more definitive epi demiological reassessment than had been possible before. The extent of seasonal variation from 1992-5 fell by about half, occurring mainly a s a single step down in 1992. The fall was relatively greater in winte r than in summer. Before 1992 the extent of seasonal variation (amplit ude) was greater in those age greater than or equal to 5 months compar ed with those aged less than or equal to 4 months. Since 1992 the fall s in incidence and amplitude have been greater ire the younger group, suggesting that SIDS deaths in younger and older babies may have diffe rent causes.