Symptoms of Asthma Extracted Through Natural Language Processing and Their Associations With Acute Asthma Exacerbation in Adults With Mild Asthma.

Abstract

Individuals with mild asthma account for 30% to 40% of asthma exacerbations requiring emergency consultation, and nearly 30% had not-well controlled or poorly controlled asthma symptoms over the previous 4 weeks. We sought to estimate the prevalence of various asthma symptoms and assess their association with future acute asthma exacerbations (AAEs) in patients with mild asthma. This was a retrospective cohort study. Using administrative data, we identified 198,873 adults aged 18 to 85 years, who met criteria for mild asthma between 2013 and 2018. The presence of cough, wheezing, dyspnea, and chest tightness in the 12 months before the index visit (t₀) was extracted from clinical notes and patient/provider communications through natural language processing. We used Poisson regression models with robust SEs to assess the associations between symptoms and AAEs in the 12 months after t₀, controlling for potential confounders. The prevalence of cough, wheezing, dyspnea, and chest tightness was 67.0%, 47.7%, 41.3%, and 13.2%, respectively. Moreover, 6.5% of patients experienced an AAE in the 12 months after t₀. All four symptoms were associated with increased AAE risk in the unadjusted analysis. After adjusting for other patient characteristics, only wheezing (adjusted relative risk, 1.13; 99% CI, 1.07-1.20) and dyspnea (1.17; 1.12-1.23) were associated with an increased risk of future AAEs. The risk increased with the frequency of the documented symptoms. Patients with mild asthma who exhibit symptoms of dyspnea and wheezing (especially on multiple occasions) are at an increased risk for future AAEs and may benefit from therapeutic intervention and/or trigger-avoidance education.