Higher incidence of SIDS at weekends, especially in younger infants.

BACKGROUND An increased incidence of sudden infant death syndrome (SIDS) at weekends has been previously noted, although it has not been found in all studies. Where a weekend effect has been found it is most prominent on Sundays. AIM To identify the magnitude of this effect in British data before and after the fall in prevalence associated with the "back to sleep" campaign. METHODS Aggregated data from England Wales, Scotland, and Northern Ireland for the years 1986-98 during which there were 12,762 deaths from SIDS were examined. RESULTS Comparing the periods before (1986-90) and after (1993-98) the fall in incidence associated with the "back to sleep" campaign, the percentage of infants dying at the weekend in the later period (32.24%) was slightly greater than for the earlier period (31.30%), although this difference was not statistically significant. In both periods the observed weekend incidences were significantly higher than the expected weekend percentage of 28.6%. Although the proportion of infants aged < or =4 months and > or =5 months at death did not change between the two periods, the weekend effect was more marked in the younger infants, particularly in the 1993-98 period. There was no consistent Saturday effect. In 1993-98 deaths appeared to be more evenly distributed throughout the week for infants > or =5 months. CONCLUSION The excess of SIDS at weekends still appears to be present despite the overall fall in prevalence associated with the "back to sleep" campaign. Increased risks at weekends might have implications for support to high risk families.