Weather and the risk of sudden infant death syndrome: the effect of wind.

STUDY OBJECTIVE To examine and identify relations between sudden infant death syndrome (SIDS) and wind, particularly the föhn wind, in Christchurch, New Zealand. DESIGN A retrospective epidemiological study combining details of regional hourly meteorological variables and reported SIDS cases. SETTING Christchurch, New Zealand, between 1968 and 1997 inclusively. PARTICIPANTS All 646 infants reported as dying from SIDS within the greater Christchurch region. MAIN RESULTS Analysis of 1968-1989 data revealed nine wind variables significantly related to SIDS. When compared with corresponding variables calculated over the 1990-1997 period, only the northerly wind on the day of death and the southerly wind three days before a SIDS death had estimated associations with similar effect size and sign. However, both these variables had confidence intervals that included unity. CONCLUSIONS No evidence was found to suspect that föhn winds influenced SIDS occurrence. The relations identified between SIDS incidence and wind, after controlling for the effects of temperature and trend, were tenuous and relatively small. More data are necessary to substantiate whether northerly winds on the day of death or southerly winds occurring three days before a death are truly associated with SIDS. It seems that wind has little, if any effect on SIDS incidence in Christchurch.