Adherence to Inhaled Therapy in Patients with COPD Associated to Pneumoconiosis

Pneumoconiosis has high prevalence of chronic obstructive pulmonary disease (COPD), respiratory morbidity, and mortality.

The aim of the present study was to examine patient characteristics and adherence to inhaled therapy among pneumoconiosis with COPD in a real-world clinical setting.

A cohort of pneumoconiosis patients with COPD prescript with at least one type of long-acting inhaled drug was followed for adherence for 2 years. Demographic and COPD-related characteristics were collected in baseline.

In baseline, after adjusting for age, dust exposure duration positively correlated with number of acute exacerbation (AE) frequency in the last year. There were close associations among COPD Assessment Tool (CAT) score, modified Medical Research Council Dyspnea Scale (mMRC) grade, number of AE, and pre-FEV₁ value. Of 296 participants originally recruited, 213 participants finished the 2-year follow-up for adherence. 122 (57.28%) were non-adherent to inhaled therapy. The most common reason for non-adherence was "relief of symptoms after short-term controller medication use" (53.28%). Patients who were non-adherent reported higher body mass index (BMI), less AE events in the last year, higher pre-FEV₁ value, higher post-FEV₁ value and low CAT, mMRC scores compared to adherent in baseline. High pre-FEV₁ value (OR = 1.04, CI = 1.018-1.064) and low mMRC scores (OR = 0.406, CI = 0.214-0.771) were risk factors found associated with non-adherence.

A majority of pneumoconiosis patients complicated with COPD have suboptimal inhaled therapy adherence. Evidence-based, adherence-enhancing interventions should be targeted on less severe subjects.