Assessment of the underreporting of rhinitis in patients with asthma: A MASK-air® real-world study

Rhinitis is a common comorbidity in patients with asthma. However, the frequency of underreported rhinitis in asthma is not known. In this study, we aimed to assess the characteristics of patients with self-reported asthma and no self-reported rhinitis, as well as the extent of the underreporting of rhinitis. We performed a cross-sectional study of all MASK-air^Ⓡ users (2015-2022, 27 countries), comparing reported symptoms and medication use in patients with (i) self-reported asthma without rhinitis ("asthma alone"), (ii) self-reported rhinitis+asthma and (iii) self-reported rhinitis without asthma ("rhinitis alone"). In patients reporting asthma alone and providing MASK-air^Ⓡ data in at least three different months, a cluster analysis was performed to potentially identify groups of patients underreporting rhinitis and/or undertreated for rhinitis. We assessed 35,251 users (529,751 days): 671 (1.9%) reporting asthma alone 25,882 (73.4%) reporting rhinitis alone and 8698 (24.7%) reporting rhinitis+asthma. Overall, 27% of the patients reporting asthma alone were treated with rhinitis medications. Patients reporting asthma alone displayed a lower frequency of days under rhinitis medication and less severe nasal symptoms than those reporting rhinitis+asthma. Among patients reporting asthma alone, three clusters of patients were identified: (A; 22.2%) severe rhinitis symptoms and low frequency of rhinitis medication use, (B, 41.0%) moderate rhinitis symptoms and high frequency of rhinitis medication use (41.0%), and (C, 36.8%) mild or no rhinitis symptoms and almost no rhinitis medication use. This study suggests that, among patients with self-reported asthma, the underreporting or undertreatment of rhinitis may be common.