Risk Of Hospitalization For Asthma Related To Extreme Temperature And Precipitation Events In Maryland

Abstract

Introduction: Several studies have found associations between ambient temperature and overall precipitation with risk of respiratory health outcomes such as asthma. Limited understanding exists regarding exposure to extreme weather events and risk of hospitalization for asthma. Methods: Hospitalization records for all asthma cases (ICD-9 code 493) were obtained for the state of Maryland from 2002 to 2012 along with clinical and demographic information. Extreme temperature and precipitation events were defined as days when the daily maximum temperature or precipitation exceeded the 95th percentile of county and calendar day specific maximum daily temperature and precipitation over a 30-year baseline period (1960-1989). We used a time-stratified case-crossover design to examine the association between exposure to extreme events and risk of hospitalization for asthma. Results: From 2000 to 2012, 116,470 asthma hospitalizations occurred in Maryland. We observed a 3% increase in risk of hospitalization for asthma associated with 1 unit increase in extreme temperature events (Odds Ratios (OR) 1.03; 95% Confidence Interval (CI): 1.00-1.07), with a considerably higher risk associated with summertime extreme temperature events (OR 1.22, CI: 1.14-1.31). Furthermore, the increase in risk was more pronounced among African Americans compared to Whites. Likewise, summertime extreme precipitation event was associated with a 14 % increase in risk (OR 1.14, CI: 1.06 - 1.21). Discussion: Our results indicate that extreme temperature and precipitation events increase the risk of hospitalization for asthma. Further efforts are currently underway to assess how this risk varies across geographic areas and demographic characteristics.