Evaluating the impact of coronavirus disease 2019 on asthma morbidity: A comprehensive analysis of potential influencing factors

Abstract

Background: The coronavirus disease 2019 (COVID-19) pandemic period is experiencing better asthma control, fewer exacerbations, and health care utilization, with limited data on factors that could explain this phenomenon.

Objective: To confirm these improved asthma outcomes during COVID-19 and evaluate potential contributing factors.

Methods: In 18,912 pediatric patients with asthma treated in the Children's Hospital of Orange County network from 2017 to 2020, monthly asthma-related encounters and medication summaries were extracted from electronic health records, particulate matter 2.5 (PM_2.5) air pollution from the California Air Resources Board, and influenza-like illness from Illness Surveillance Network for the first 6 months of each year. Changes in outcomes between January to March and April to June (post-COVID-19 shutdown in 2020) were compared with historical data using generalized estimating equations analyses for patient outcomes and generalized linear models for pollution exceedance, influenza-positive, and telehealth visit rates.

Results: During COVID-19, we found 78%, 90%, 68% reductions in hospitalization, emergency department visits, and exacerbations, respectively, compared with pre-COVID-19 2020, with significantly greater changes than the same time period of 2017 to 2019 and significant reductions in albuterol and inhaled corticosteroid use (P < .05). Emergency department visit reduction was not seen for African Americans. The PM_2.5 and influenza rates were also significantly reduced during COVID-19 (P < .05). Increased rates in telehealth visits were greater in the publicly insured group when compared with commercially insured.

Conclusion: Our data confirm reduced health care utilization and suggest better asthma control during COVID-19, except for African Americans. This was associated with a significant increase in telehealth visits and reductions in PM_2.5 and influenza infections, but not better asthma controller adherence.

Figure 1

Monthly morbidity rates per 1000 patients with asthma. Rates were significantly lower in April to June compared with January to March across years and, to an even greater extent, in 2020 compared with previous years (P < .05). Poisson regression using GEE analyses with the specification of repeat measures. CI, confidence interval; ED, emergency department; GEE, generalized estimating equations; IRR, incidence rate ratios; OCS, oral corticosteroid.

Figure 2

Monthly medication prescription rates per 1000 patients with asthma. Rates were significantly lower in April to June compared with January to March across years and, to an even greater extent, in 2020 compared with previous years (P < .05). Poisson regression using GEE analyses with the specification of repeat measures. CI, confidence interval; ED, emergency department; GEE, generalized estimating equations; IRR, incidence rate ratios; OCS, oral corticosteroid; Rx, prescription.

Figure 3

Average days per month daily average PM_2.5 pollution levels exceeded WHO standard (≥10.0 ug/m³) and monthly influenza rates per 1000 patients in reporting practices within California during respective time periods. Poisson regression using GLM analyses. Two-way interaction effect shows significant pre/post changes in 2020 vs previous years for both PM2.5 (P = .01), and influenza infection (P = .04). CI, confidence interval; GLM, generalized linear models; IRR, incidence rate ratios; PM2.5, particulate matter with diameter less than 2.5 micrometers; WHO, World Health Organization.