Even Moderate Heat Increases Spur More ED Visits
October 6th, 2016
PROVIDENCE, RI – How would emergency departments be affected by climate change? In attempting to answer that question, a new study finds more visits for emergency care in one state even when rising temperatures are well below what would be considered extreme.
Temperatures above 75 degrees create a noticeable increase in medical distress among Rhode Island residents of all ages, according to the report published recently in the journal Environmental Health Perspectives.
For the study, researchers at Brown University and the Rhode Island Department of Health conducted a detailed statistical analysis of ED visits, deaths and weather data from recent years, including additional factors such as ozone levels. Medical records provided information on when emergency physicians deemed a patient's condition to be related to heat or dehydration.
"Our primary finding is that as temperatures increase, the number of emergency room visits and deaths increase," said lead author Samantha Kingsley, a Brown University public health graduate student. "But people were going to the hospital for heat-related reasons at temperatures below what we would typically consider extreme."
While the rate of heat-related ED visits jumped only 3.3% on days with a high of 75 degrees vs. days with a high of 65, those visits shot up 23.9% on days with a high of 85 degrees vs. 75. Study authors determined that overall temperature began to play an independent role in increasing ED visits beginning at about 75 degrees.
At the same time, Rhode Island’s death rate was 4% on a typical 85-degree day vs. a typical 75-degree day – even though neither temperature really is considered extreme, study authors point out.
"People should be aware that heat represents a significant public health threat," senior author Gregory Wellenius, ScD, associate professor of epidemiology, explained in a Brown University press release. "We do need to take heat seriously as a public health risk, even if there isn't a heat warning."
Interestingly, study results found the strongest association between heat-related ED visits and higher temperatures not among the elderly but among Rhode Islanders aged 18-64.
The study authors questioned whether some of those affected could be outside workers.
"Everybody believes that heat is dangerous but not for them," Wellenius said. "One of the messages is that this is really across the age spectrum. Heat remains one of the leading causes of weather-related deaths."
To investigate the possibility that the rate of heat distress would increase with climate change, the researchers projected how much greater ED visits and mortality would be if the current Rhode Island population were living with the increased temperatures forecast by two standard models of global warming. One projects a 6-degree rise by the end of the century and the other a 10-degree rise for two ranges of years: 2046-53 and 2092-99.
The researchers forecast that if days became 10 degrees hotter by the end of the century, the state's summertime death rate would rise by about 1.5% percent, representing about 80 more deaths each summer. The rate of heat-related ED visits would increase by about 25%, from about 6,000 to about 7,500 each summer, they add.