Evaluation of adherence to guideline-directed therapy and risk factors for exacerbation in mild asthma: a retrospective chart review

Abstract Background A significant update was made to both the Global Initiative for Asthma (GINA) in 2019 and the National Heart Lung and Blood Institute (NHLBI) asthma guidelines in 2020 for mild asthma. These groups no longer recommend short-acting beta-agonists (SABA) as monotherapy for mild (GINA) or mild-persistent (NHLBI) asthma. With the lag that can occur between guideline or evidence updates and changes in practice, this study sought to evaluate whether guideline adoption had occurred. Methods In this retrospective chart review, patient electronic medical records from a large healthcare system were evaluated from July 1 of 2021 to July 1 of 2022 to determine how many patients with mild asthma were prescribed as needed or daily inhaled corticosteroids (ICS) in addition to as needed SABA. The secondary outcome was to evaluate the incidence of exacerbations in patients with mild asthma, comparing those on guideline-directed therapy or not. In addition, we evaluated other patient factors increasing exacerbation risk in mild asthma. Results For the primary outcome, of the 1,107 patients meeting inclusion criteria, 284 patients (26%) did not have documentation of guideline-directed therapy for mild asthma during the study period, while 823 (74%) were on guideline-directed therapy (Diff:48.7%; 95% CI:45.1 to 52.3%, p < 0.001). For the secondary objective, 161 patients had an exacerbation (12% on guideline-directed therapy, 15.4% not on guideline-directed therapy). This difference in incidence of exacerbation between the two treatment groups was not statistically significant (Diff: -3.4%; 95% CI: -8 to 1.1%; p = 0.133). In addition, being female, having GERD, and being obese were all statistically significant factors associated with having asthma exacerbations among our patient population. Conclusions Nearly one-fourth of patients with mild persistent asthma were not on guideline-directed therapy, despite updates in asthma guidelines (GINA 2019, NHLBI 2020). Factors such as being female, having GERD, and being obese were all statistically significant factors associated with having asthma exacerbations among patients with mild persistent asthma.