Treatment Adherence and Treatment Effectiveness in Stable Chronic Obstructive Pulmonary Disease Among Outpatients at...

Recently, early prevention, treatment, and stabilization of chronic obstructive pulmonary disease (COPD) have become key priorities to reduce exacerbations and improve respiratory function. This study is aimed at evaluating treatment adherence and effectiveness among outpatients with stable COPD in Vietnam.

A cross-sectional descriptive study was conducted on 400 stable COPD outpatients at Kien Giang General Hospital (June 2024-June 2025). Treatment adherence was assessed using the 8-item Morisky Medication Adherence Scale (MMAS-8). Treatment effectiveness was evaluated using three criteria: the number of exacerbations and hospitalizations in the previous 12 months, the modified Medical Research Council (mMRC) dyspnea scale score, and the COPD Assessment Test (CAT) score at two time points: T₀ (baseline) and T (after 3 months of outpatient follow-up).

After 3 months of outpatient follow-up, the treatment adherence rate was 76.5%. The chosen treatment regimen was significantly associated with medication adherence (p < 0.001). Patients using regimens (ICS/LABA + LABA [p.o.]), (SABA + ICS/LABA), and (SABA + ICS/LABA + LABA [p.o.]) had higher adherence than those using ICS/LABA alone. The overall treatment effectiveness improvement rate was 70.3%, with improvements in exacerbations/hospitalizations in the previous 12 months (23.0%), mMRC score (32.3%), and CAT score (66.0%). Although the treatment efficacy index showed positive trends for exacerbations/hospitalizations (11.0%, p = 0.076), mMRC score (3.1%, p = 0.375), and CAT score (3.5%, p = 0.088), these changes did not reach statistical significance, indicating only early positive trends over the 3 months. Multivariate logistic regression analysis identified treatment adherence and smoking status as the strongest predictors of treatment effectiveness.

Patients with good adherence had substantially higher treatment effectiveness than those with poor adherence. Conversely, smoking status was negatively associated with treatment effectiveness. Further interventional studies targeting these factors are needed to improve medication adherence and treatment effectiveness in patients with stable COPD.