Patient Adherence to COPD Medications Linked to Perceived Severity of Disease, Study Says

Patient adherence to medication is a complex issue, particularly so for patients with chronic obstructive pulmonary disease. A recent study finds that adherence is related to need perception and to the functional severity of the disease.

In patients with COPD, long-term adherence to inhaled medications is required for success of the treatment, but adherence is difficult to measure, and researchers are still trying to understand patient-related determinants.

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In this study, patients with stable COPD who were 40 years and older were included in a cross-sectional study. They were diagnosed according to the Global Initiative for Chronic Obstructive Lung Disease criteria. Researchers administered the Measure of Treatment Adherence (MTA), the Beliefs about Medications Questionnaire (BMQ), and demographic, clinical, and COPD questionnaires. Semistructured interviews were performed, and each interview was analyzed before the next one. Researchers analyzed quantitative and qualitative variables.

Other studies have found that correct inhaler technique is crucial for patient adherence. Other factors could include comorbid depression or the Medicare Part D coverage gap.

A total of 300 of 319 participants (mean age, 67.7 years; 78.1% males) completed the MTA questionnaire. Of these, 31.3% were considered poorly adherent and 16.7% as nonadherent to inhaled medication.

A statistically significant negative association was found between adherence and current smoking status (P = .044) and between adherence and postbronchodilator forced expiratory volume in 1 second (P = .000).

The mean BMQ Necessity score was higher in adherent patients (P = .000), but the mean Concern score was similar for both (P = .877).

Researchers found information about the patterns and reasons for different adherence behaviors, which are based on 3 major groups of patient-related determinants: health-related experiences, health-related behaviors, and health-related beliefs. Researchers found 9 patterns of poor adherence, 6 reasons given for poor adherence behaviors, 5 reasons for good adherence behaviors, and 3 patient-related domains on adherence to medications.

Only 31.3% of the participants were considered poorly adherent and 16.7% were considered nonadherent. The patients’ beliefs regarding the treatment of the disease were found to be the most powerful predictors of adherence to inhalation therapy.

A nonadherent patient was usually a current smoker with lower degree of airflow limitation and lower perception of medication necessity.

The authors also said that low socioeconomic status and low education level are contributing factors for a widespread lack of knowledge about COPD.

The study had some limitations. It was conducted in a single institution and had a small sample size. Also, selection bias cannot be excluded since patients were recruited sequentially. But the researchers said the link “between adherence and the beliefs about the need for inhaled medications and the functional severity of the disease is new and important information.”

Reference

Duarte-de-Araújo A, Teixeira P, Hespanhol V, Correia-de-Sousa J. COPD: understanding patients’ adherence to inhaled medications [published online September 6, 2018]. Int J Chron Obstruct Pulmon Dis. doi: 10.2147/COPD.S160982.