OBJECTIVES : Previous ecologic studies have shown increased asthma-related healthcare resource use during periods of high pollen counts. This study’s objective was to characterize the rate of asthma-related inpatient (IP) admissions and emergency department (ED) visits in children with asthma using patient-level claims and linked weather data.

METHODS : Children with asthma were identified in the IBM MarketScan Commercial Database, linked to the IBM MarketScan Weather Database, and required to be 12 or younger on 1/1/2016 with continuous enrollment through 12/31/2016. Asthma-related IP admissions and ED visits during 2016 were identified; grass and tree pollen levels (e.g., none, low, moderate, high/very high) were assigned using the maximum pollen index value in the five days prior to the encounter. Incidence rates (IR) of IP admissions and ED visits per 100,000 patient days were calculated by pollen level; incidence rate ratios (IRR) and 95% confidence intervals (95% CI) were used to compare IR.

RESULTS : 225,776 children with asthma and linked weather data were included in this study; 61% were male. IR for both asthma-related IP admissions and ED visits were highest when pollen counts were high/very high (grass: IP 2.41, ED: 37.88; tree: IP 1.83, ED 28.42). IRR for asthma-related IP admissions on high/very high grass pollen days (IRR: 1.60; 95% CI: 1.25-2.05) and tree pollen days (IRR: 1.50, 95% CI: 1.21-1.87) compared to no pollen days were significant. For ED visits, IRR on high/very high grass pollen days (IRR: 1.85, 95% CI: 1.73-1.97) and tree pollen days (IRR: 1.63, 95% CI: 1.54-1.72) relative to no pollen days were also significant.

CONCLUSIONS : Higher pollen counts are associated with higher incidence of asthma-related IP admissions and ED visits in children with asthma. Further research is necessary to evaluate whether additional weather conditions are associated with asthma-related healthcare resource use in children with asthma.