Weather and deaths in Pittsburgh, Pennsylvania: a comparison with Birmingham, Alabama

The relationship between weather and daily mortality was examined over a four-year period in the temperate climate of Pittsburgh, PA. Eight weather parameters were correlated with daily mortality by using multiple, simple, and partial correlation techniques. Results from this study were then compared with results obtained from a previous investigation involving an identical analysis of the effects of weather on death in the subtropical climate of Birmingham, AL. Although the relationship between weather and total mortality is statistically significant in both areas, weather in the temperate region accounts for a greater portion of the daily variation in number of deaths. In both cities, the effect of weather increases with age and is more intense among the white than the nonwhite population, but does not appear to vary with sex. In both places, weather significantly influences death from respiratory and circulatory diseases, but hardly affects mortality from cancer or behaviorally related causes. The cities differ in that Pittsburgh weather is significantly associated with deaths from ischemic heart disease, but not with cerebrovascular mortality, while the reverse is observed in Birmingham. The cities also differ in specific meteorological factors, and in the seasonal distribution of the intensity of the weather-mortality relationship.