Seasonal patterns of morbidity and mortality in the elderly in Ireland.

Weather conditions have been shown to have a strong association with health Status. (1,2) In this study we examined the relationship between meteorological conditions (average daily temperature, humidity, precipitation, and wind strength) and the seasonal morbidity (emergency hospital admissions and drug prescribing) and mortality patterns in the elderly (over 65 years) over a four year period in Ireland. Temperature (summer/winter variation of 10 degrees C) had the strongest (inverse) association with total mortality (correlation coefficient of 0.895). Circulatory diseases showed the strongest seasonal trend in mortality and a weaker trend for admissions. For respiratory diseases, the morbidity and admission seasonal patterns were similar. Circulatory and respiratory drug prescribing showed no strong seasonal pattern. On examination of the excess winter mortality in four different regions, it was found that the smallest summer/winter temperature difference (9.96 degrees C) occurred in Cork and was associated with the highest percentage difference in total mortality. The highest temperature difference (10.80 degrees C) occurred in Monaghan and this area was associated with the lowest percentage difference in total mortality.