Association of Patient-Reported Outcome Patterns and Major Clinical Factors with Frailty in Stable COPD

Chronic obstructive pulmonary disease (COPD) exhibits heterogeneous symptom profiles across individuals. This study aimed to identify subgroups of patients with stable COPD according to physiological, psychological, and environmental symptoms; assess differences in their characteristics; and examine the association of symptom patterns with frailty.

We analyzed data from the second wave of a cohort study involving patients with COPD reassessed 6 months after hospitalization for acute exacerbations. Frailty and patient-reported outcomes were measured using the FRAIL and Modified COPD-Patient-Reported Outcome (mCOPD-PRO) scales. Latent profile analysis identified subgroups based on mCOPD-PRO symptom patterns. Differences across symptom severity subgroups were assessed using post-hoc trend analyses and chi-square tests for trends. Multinomial logistic regression quantified the magnitude of differences between subgroups. The relationship between subgroups, clinical factors, and frailty was examined through linear regression.

Among 308 patients with stable COPD, three subgroups were identified: "low-symptom" (27.9%), "moderate-symptom" (51.3%), and "severe-symptom" (20.8%). Body mass index, Global Initiative for Chronic Obstructive Lung Disease stage (GOLD), COPD Assessment Test (CAT) score, modified Medical Research Council (mMRC) score, and physical activity exhibited significant linear trends across subgroups of increasing symptom severity. Frailty scores differed significantly: 0.50 ± 0.78 in the low-symptom group, 1.34 ± 0.96 in the moderate-symptom group, and 2.72 ± 0.95 in the severe-symptom group. Multivariate analysis identified severe-symptom group (β coefficient [β]=0.62, 95% confidence interval [CI]: 0.21-1.03), rural residence (β=0.21, 95% CI: 0.04-0.39), GOLD (β=0.23, 95% CI: 0.07-0.39), mMRC (β=0.17, 95% CI: 0.03-0.31), and CAT score (β=0.04, 95% CI: 0.02-0.06) associated with frailty.

Patients with stable COPD can be categorized based on patient-reported outcomes, with differences in demographic and disease characteristics across subgroups. Patients with severe COPD symptoms revealed higher levels of frailty compared to those with low symptoms.