摘要：Objectives. This study examined whether differences in heat alone, as opposed to public health interventions or other factors, accounted for the reduction in heat-related deaths and paramedic emergency medical service (EMS) runs between 1995 and 1999 during 2 heat waves occurring in Milwaukee, Wis. Methods. Two previously described prediction models were adapted to compare expected and observed heat-related morbidity and mortality in 1999 based on the city's 1995 experience. Results. Both models showed that heat-related deaths and EMS runs in 1999 were at least 49% lower than levels predicted by the 1995 relation between heat and heat-related deaths or EMS runs. Conclusions. Reductions in heat-related morbidity and mortality in 1999 were not attributable to differences in heat levels alone. Changes in public health preparedness and response may also have contributed to these reductions. From 1979 through 1997, an average of 371 Americans per year died from excessive heat, more than the number dying as a result of earthquakes, lightning, hurricanes, tornadoes, and floods combined. 1 During heat waves, heat-related morbidity and mortality can increase dramatically. 2– 13 During a 1995 heat wave in the upper midwestern United States, an estimated 700 people died from heatrelated illness in Chicago, Ill, alone. 9 In Milwaukee County, Wis, in 1995 and 1999, heat contributed to 91 and 11 deaths, respectively. 7, 14, 15 In these same years, respectively, 95 and 28 heat-related paramedic emergency medical service (EMS) runs were made. In the present study, we sought to determine whether the reductions in heatrelated deaths and paramedic runs (heatrelated outcomes) in 1999 were the result of differences in heat levels alone. We used 2 different methods relating heat levels to heat-related outcomes to quantify the changes observed between 1995 and 1999.
