Sex and Age Characteristics of Thunderstorm Asthma Emergency Department Visits in a Midwest Metropolitan Environment (2007-2018)

Abstract

Background Severe asthma has been shown to occur in the combined presence of high pollen and thunderstorm conditions, also known as ‘thunderstorm asthma.’ Studied as severe epidemic events, recent work has explored less dramatic, but more persistent chronic occurrences. We explore thunderstorm asthma-related emergency department (ED) visits in the Minneapolis-St. Paul region and evaluate unknown risk differences by sex and age groups. Methods We define a thunderstorm asthma exposure event as daily occurrence of 2 or more lightning strikes during high pollen periods. We use daily counts of asthma-related ED visits from the Minnesota Hospital Association (2007-2018). We estimate relative and absolute risk of severe asthma during thunderstorm asthma events for the full population and sex and age subgroups. Results The overall population had a 1.055 (95% CI: 1.019, 1.093) relative risk of asthma-related ED visits during thunderstorm asthma conditions. We observe a greater relative risk on the day of the exposure for males (RR 1.07; 95% CI: 1.02, 1.12) compared to females (RR 1.04; 95% CI: 1.00, 1.09), and observed age 18-44 years and 45 and up to be most vulnerable. Children have no significant increase in ED visits during thunderstorm asthma events. Absolute risk counts show similar patterns to these age and sex results, but age-sex subgroups show more variation in absolute vs relative risk for males compared to females. Conclusions Our results support an association between ED visits and thunderstorm asthma, and provide evidence of varying risk by sex across the life course. Thunderstorm asthma shows a unique pattern where middle-aged males and older females show the greatest risk, unlike baseline asthma incidence that is greatest in male children and middle-aged females. These patterns have implications for unrecognized at-risk groups and provide clinical information for this unique asthma exposure. Keywords Climate change, thunderstorm asthma, pollen, ED visits