More seniors are hospitalized for respiratory disorders as the outdoor temperature rises, study finds

Seniors are increasingly likely to be hospitalized for respiratory problems as it becomes warmer, according to a recently released study.

Researchers at the Johns Hopkins Bloomberg School of Public Health studied 1999-2008 Medicare information of more than 12.5 million beneficiaries living in 213 urban U.S. counties. They found summertime hospitalizations for respiratory disorders increased 4.3% for each 10-degree Fahrenheit increase in daily mean temperature. This equates to about 30 extra hospitalizations per day in the areas studied.

The risk of hospitalization is greatest on the day of short-term exposure to outdoor heat, but seniors are still at increased risk the day after exposure, researchers said.

"While outdoor heat has been shown to increase respiratory mortality, evidence on the relationship between heat and respiratory hospitalizations has been less consistent," said lead author G. Brooke Anderson, Ph.D., postdoctoral fellow in the Department of Biostatistics at the Johns Hopkins Bloomberg School of Public Health. "We found strong evidence that short-term exposure to outdoor heat increases the risk of hospitalization for COPD and respiratory tract infections. This relationship was consistent for men and women and across all age groups studied."