Psychological Well-Being and Treatment Adherence in COPD Patients: A Correspondence Analysis of WHO-5, MARS, and GOLD Severity

Background: Chronic obstructive pulmonary disease (COPD) is frequently complicated by psychological distress and suboptimal treatment adherence, both of which adversely affect clinical outcomes. However, the relationship between disease severity, emotional well-being, and adherence behavior remains insufficiently characterized. Methods: This multicenter observational study included 285 patients with COPD recruited from two primary care clinics. COPD severity was classified according to GOLD criteria. Psychological well-being was assessed using the World Health Organization–Five Well-Being Index (WHO-5), and treatment adherence was evaluated using the Medication Adherence Report Scale (MARS). Multidimensional relationships between clinical variables, WHO-5, and MARS were explored using correspondence analysis with symmetrical normalization. Results: Most patients had severe or very severe COPD (GOLD 3–4, 65.6%). WHO-5 scores showed marked heterogeneity across all GOLD stages, with very low values (20–26%) contributing disproportionately to the overall data structure (total contributions up to 0.97), indicating substantial anxiety and depression-related burden. Non-adherent patients represented 28.4% of the cohort but accounted for 71.6% of the inertia in the adherence-related correspondence analysis, forming a distinct psychological and behavioral profile. Mean GOLD stage was comparable between adherent and non-adherent patients (approximately 2.8–3.0). Conclusions: Correspondence analysis demonstrated substantial heterogeneity in WHO-5 and MARS profiles across all GOLD stages. Notably, mean GOLD severity was comparable between adherent and non-adherent patients (approximately 2.8–3.0), indicating that differences in adherence behavior were not primarily driven by spirometric disease severity.