Risk factors for acute asthma exacerbation in adults with mild asthma
Published online May 28, 2024
The prevalence of asthma has increased since the early 1980s in all age, sex, and racial groups. European data suggest that although increased prevalence has occurred in all severity categories, the increase has been largest among those with mild-to-moderate asthma. Mild asthma patients are currently estimated to constitute 50-75% of the asthma population and their reported prevalence is likely to be underestimated. Despite being categorized as having mild disease, a significant proportion of patients with mild asthma have considerable clinical burden and healthcare resource utilization.
Chen et al. recently published a retrospective cohort study in The Journal of Allergy and Clinical Immunology: In Practice in which they identified 199,010 adults aged 18-85 from the large Kaiser Permanente Southern California managed care organization who met study criteria for mild asthma between 2013-2018. Because the current study is based on electronic health records (EHR), which typically contain incomplete information on asthma symptom frequency, the authors identified a phenotypic group of patients defined by low asthma medication use and low asthma-related health care utilization as a proxy for guidelines-defined mild asthma. First, an asthma-coded qualifying visit (index visit) was identified for each patient. The authors then followed these patients with study-defined mild asthma over time to estimate the prevalence of future acute asthma exacerbation (AAE) and to identify risk factors associated with future AAEs. An AAE was defined as either (1) an asthma-coded hospitalization or ED visit, or (2) an asthma-related systemic corticosteroid administration (intramuscular or intravenous) or oral corticosteroid dispensing.
The mean age of the study cohort was 44, 64% were female, 6.5% had AAEs within one year after the index visit. Older age, being female, Black, Asian/Pacific Islander, Hispanic, a current smoker, or overweight/obese and having history of allergic rhinitis, chronic sinusitis, nasal polyps, elevated eosinophil counts, and prior acute or non-acute asthma care all increased the risk of future AAE. Prior dispensing of antidepressants, antibacterial or antimicrobial agents, calcium channel blockers and proton pump inhibitors increased the risk of AAE by a magnitude of 6%-10%, while insulin and metformin decreased the risk of AAE by 17% and 9%, respectively.
This retrospective study suggests that risk factors for future AAE in patients with mild asthma are similar to those found in patients with moderate-to-severe asthma. Expanding population management strategies to include patients with mild asthma via identification of relevant risk factors and institution of appropriate preventive interventions may reduce the risk of future AAE and minimize asthma burden in this large and important subset of asthma patients.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.
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