Exposure to extreme heat and precipitation events associated with increased risk of hospitalization for asthma in Maryland, U.S.A.
BACKGROUND
Several studies have investigated the association between asthma exacerbations and exposures to ambient temperature and precipitation. However, limited data exists regarding how extreme events, projected to grow in frequency, intensity, and duration in the future in response to our changing climate, will impact the risk of hospitalization for asthma. The objective of our study was to quantify the association between frequency of extreme heat and precipitation events and increased risk of hospitalization for asthma in Maryland between 2000 and 2012.


METHODS
We used a time-stratified case-crossover design to examine the association between exposure to extreme heat and precipitation events and risk of hospitalization for asthma (ICD-9 code 493, n = 115,923).


RESULTS
Occurrence of extreme heat events in Maryland increased the risk of same day hospitalization for asthma (lag 0) by 3 % (Odds Ratio (OR): 1.03, 95 % Confidence Interval (CI): 1.00, 1.07), with a considerably higher risk observed for extreme heat events that occur during summer months (OR: 1.23, 95 % CI: 1.15, 1.33). Likewise, summertime extreme precipitation events increased the risk of hospitalization for asthma by 11 % in Maryland (OR: 1.11, 95 % CI: 1.06, 1.17). Across age groups, increase in risk for asthma hospitalization from exposure to extreme heat event during the summer months was most pronounced among youth and adults, while those related to extreme precipitation event was highest among ≤4 year olds.


CONCLUSIONS
Exposure to extreme heat and extreme precipitation events, particularly during summertime, is associated with increased risk of hospitalization for asthma in Maryland. Our results suggest that projected increases in frequency of extreme heat and precipitation event will have significant impact on public health.
Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, 2234F SPH Building #255, College Park, 20742, MD, USA.
Sutyajeet
S
Soneja
Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, 2234F SPH Building #255, College Park, 20742, MD, USA.
Chengsheng
C
Jiang
Department of Epidemiology, University of Maryland School of Public Health, College Park, 20742, MD, USA.
Jared
J
Fisher
Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, 2234F SPH Building #255, College Park, 20742, MD, USA.
Crystal Romeo
CR
Upperman
Maryland Department of Health and Mental Hygiene, Prevention and Health Promotion Administration, Baltimore, MD, USA.
Clifford
C
Mitchell
Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, 2234F SPH Building #255, College Park, 20742, MD, USA. amirsap@umd.edu.
Amir
A
Sapkota
D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D055874:Extreme Heat / Q000009:adverse effects*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008396:Maryland / Q000453:epidemiology; D008875:Middle Aged; D016017:Odds Ratio; D011891:Rain; D012306:Risk; D055815:Young Adult
Asthma; Climate change; Extreme weather; Heat; Hospitalization; Precipitation; Respiratory illness