Latent Classes Of Adults With Persistent Asthma: Data From The Multicentre Inspirers Studies

Unsupervised methods may unveil the potential of the INSPIRERS studies to comprehend the heterogeneous characteristics of asthma. Therefore, we aimed to identify distinct classes of asthma among the participants, using latent class analysis (LCA), and to compare their characteristics across classes. We applied LCA to 308 adults (≥18 years) with persistent asthma (treated with daily inhaled medication) participants in the observational and prospective INSPIRERS studies, conducted in 26 secondary care outpatient clinics from Portugal and Spain. The classifying variables included asthma-related demographics, unscheduled healthcare use, Control of Allergic Rhinitis and Asthma Test (CARAT), and EuroQol 5 dimensions (EQ-5D) questionnaires. A three-class model was identified. Class 1 (21%) and Class 2 (26%) were characterized by highly symptomatic and uncontrolled asthma, with concomitant upper airways symptoms and reporting problems across all EQ-5D dimensions; they differed on high unscheduled healthcare use (Class 1) and early asthma onset (Class 2). Class 3 (53%): early asthma onset, controlled asthma with upper airways symptoms and without problems in EQ-5D dimensions. Compared to other classes, Class 1 had a higher proportion of subjects with FEV1<80% (p<0.001), and subjects in Class 3 were younger (p<0.001) and predominantly male (p=0.03). Smoking status, obesity or self-reported inhaler adherence did not differ among classes. Three distinct and clinically meaningful unsupervised classes of asthma were identified among participants of the INSPIRERS studies, revealing the studies’ potential to support and enable patient-centered care and further research.