Inhaled Medication Adherence Trajectory and Its Associated Factors in Patients with Chronic Obstructive Pulmonary...

This study aims to identify the heterogeneous trajectories of inhaled medication adherence in COPD patients while examining their associated factors and exploring the longitudinal correlation between variables, so as to provide the basis for precise intervention.

Adopting convenience sampling, chronic obstructive pulmonary disease (COPD) patients hospitalized at The First Affiliated Hospital of Guangzhou Medical University between December 2023 and September 2024 were recruited. General information, Test of the Adherence to Inhalers (TAI; scores of 50 indicate high adherence, 46-49 moderate adherence, and ≤45 low adherence), Chronic Obstructive Pulmonary Disease Knowledge Questionnaire (COPD-Q), Beliefs about Medicines Questionnaire-Specific (BMQ-Specific), Hospital Anxiety and Depression Scale (HADS), and Perceived Social Support Scale (PSSS) were assessed at hospitalization (T0) and 1 month (T1), 3 months (T2), and 6 months (T3) after discharge. The Group-Based Trajectory Model was employed to identify inhaled medication adherence trajectories. Associated factors of trajectories were determined using multinomial logistic regression, and the longitudinal association between variables was explored by the Group-Based Dual Trajectory Model.

A total of 207 patients with COPD completed follow-up. The number and proportion of COPD patients with "medium-low adherence" showed a significant decrease from T0 to T1, followed by an increase from T1 to T3. Trajectories of inhaled medication adherence in COPD patients can be categorised into four classes: "high adherence-persisting group" (50.4%), "medium-low adherence-persisting group" (18.4%), "low adherence rising-persisting group" (15.0%), and "low adherence rising- declining group" (16.3%). Duration of inhalation device use, health literacy, beliefs about medicines, anxiety, and perceived social support were associated factors of trajectories of inhaled medication adherence (P < 0.05), with a significant positive correlation between trajectories of inhaled medication adherence and trajectories of beliefs about medicines.

Nearly one-third of COPD patients exhibited poor inhaled medications adherence after discharge, with one month post-discharge serving as a critical turning point. Healthcare providers should prioritize monitoring adherence changes during this period. Four heterogeneous adherence trajectories were identified. Factors influencing each trajectory included: duration of inhaler device use ≤2 years, low level of health literacy, low level of beliefs about medicines, high level of anxiety, and low level of perceived social support. Early screening of these populations and implementation of targeted strategies are essential to enhance precision management.