Evaluating the different responses in morbidity and mortality to heat events across New York State

The health impacts of excessive heat have been studied extensively, usually using mortality data. Fewer works have examined morbidity data, and fewer still have examined both in a systematic fashion to evaluate the differential impacts of heat on morbidity and mortality.

This research assesses the relationship between heat events and morbidity and mortality across New York State for the period 1991-2004. Heat events are defined based on the Spatial Synoptic Classification. Counts of direct heat-related deaths and hospitalizations, and standardized anomalies of all-cause, respiratory, and circulatory-related deaths and admissions, are assessed using distributed-lag models and other statistical analyses. The state of New York is divided up into 8 regions based on climate similarity in this research, with additional work being performed just on New York City due to its large sample size.

The highest rates of heat mortality and morbidity are found in metropolitan New York City. A greater relative increase in morbidity appears during heat events that include Dry Tropical days, compared with events that were entirely hot and humid (Moist Tropical Plus). Heat-related mortality increases appear to be more pronounced earlier in the warm season, while morbidity data sets show the largest increases in mid-summer. During heat events, for causes other than those directly related to heat increases in mortality occur, while increases in morbidity are minimal. High admission days were better correlated with a measure of frequency of oppressive days over the past week than with the weather type on the actual day.