272709 Effects of heat on stroke hospitalizations in Allegheny County, Pennsylvania

Monday, October 29, 2012

Sandie Ha, MPH , College of Public Health and Health Professions, College of Medicine, Department of Epidemiology, University of Florida, Gainesville, FL
Evelyn O. Talbott, DrPH, MPH , Department of Epidemiology, Director University of Pittsburgh Academic Center for Excellence in Environmental PH Tracking, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA
Haidong Kan, PhD , School of Public Health, Fudan University, Shanghai, China
Cindy Prins, PhD, MPH, CIC , College of Public Health and Health Professions, University of Florida, Gainesville, FL
Xiaohui Xu , College of Public Health and Health Professions, College of Medicine, Department of Epidemiology, University of Florida, Gainesville, FL
Background: Heat has been known to increase the risk of many health endpoints. However, few studies have examined its effects on stroke. The objective of this case-crossover study is to investigate the effects of high heat and its effect modifiers on the risk of stroke hospitalization in Allegheny County, Pennsylvania.

Methods: We obtained data on first stroke hospitalizations among adults ages 65 and older and daily meteorological information during warm seasons (May-September) from 1994 to 2000 in Allegheny County, Pennsylvania. Using conditional multiple logistic regressions, the effects of heat days (any day with a temperature greater than the 95th percentile) and heat wave days (at least two continuous heat days) on the risk of stroke hospitalization were investigated. The potential interactions between high heat and age, type of stroke and gender were also examined.

Results: Heat day and heat wave at lag-2 day were significantly associated with an increased risk for stroke hospitalization (OR=1.121, 95%CI: 1.013-1.242; OR=1.173, 95%CI: 1.047-1.315, respectively) after adjusting for important covariates. In addition, having two or more heat wave days within the four-day window prior to the event was also significantly associated with an increased risk (OR=1.119, 95%CI: 1.004, 1.246) compared to having no heat wave days during the period. The effect of high heat on stroke was more significant for ischemic stroke, men, and subjects ages 80 years or older.

Conclusion: Our study suggests that high heat may have adverse effects on stroke and that some subgroups may be particularly susceptible to heat.

Learning Areas:
Chronic disease management and prevention
Environmental health sciences

Learning Objectives:
1)Determine the association between heat exposure and risk of stroke hospitalization 2)Examine the effects of different patterns of heat exposure on risk of stroke hospitalization 3)Assess the potential effect modifications of type of stroke, gender and age on these associations

Keywords: Environmental Exposures, Strokes

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: although I am a new scientist in the field, I have many research experience working closely with environmental exposure studies with my research mentor, who has great expertise in the field including multiple funded projects and peer-reviewed publications. I am also currently a doctoral student in Epidemiology with great interests in the effects of environmental exposures on different disease endpoints, and numerous related works.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.