COPD: understanding patients’ adherence to inhaled medications

Abstract

Background and objectiveAdherence to inhaled medications by COPD patients is a challenging issue, but relatively understudied. The aim of this study is the characterization of adherence to inhaled medications by COPD patients, with a focus on patient-related determinants.MethodsStable COPD outpatients ≥40 years of age from a respiratory unit and diagnosed according to the Global Initiative for Chronic Obstructive Lung Disease criteria were included in a cross-sectional study. The Measure of Treatment Adherence (MTA), the Beliefs about Medications Questionnaire (BMQ) and demographic, clinical, and COPD questionnaires were used. After completing these questionnaires, semi-structured interviews were carried out and participants were encouraged to justify their opinions and behaviors. Field notes were made during the interviews and each interview was analyzed before the next one. Quantitative and qualitative analyses of the variables were then performed.ResultsA total of 300 out 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 non-adherent to the inhaled therapy. A statistically significant negative association was found between adherence and current smoking status (P=0.044), and between adherence and FEV1% (P=0.000). The mean BMQ Necessity score was higher in adherent patients (P=0.000), but the the mean Concern score was similar for both (P=0.877). We found nine patterns of poor-adherence, six reasons given for poor-adherence behaviors, five reasons for good-adherence behaviors and three patient-related domains on adherence to medications.ConclusionAdherence is related to need perception and to the functional severity of the disease. A non-adherent patient is usually a current smoker with lower degree of airflow limitation and lower perception of medication necessity. New information obtained was related to the patterns and reasons for different adherence behaviors, which are based on three major groups of patient related-determinants: health-related experiences, health-related behaviors and health-related beliefs.

Barriers and Strategies for Improving Medication Adherence Among People Living With COPD: A Systematic Review

“…= 1), 26 the Measure of Treatment Adherence Scale (no. = 1), 30 and the Test of Adherence to Inhaler Scale (no. = 1).…”

“…Of the 38 included studies, 30 listed issues that hindered medication adherence. 3,[26][27][28][29][30][31][32][33][34]36,[38][39][40][41]43,44,[46][47][48][49][53][54][55][56][57][58][59][60][61] Different methods were used to assess barriers to and facilitators of medication adherence. For example, 23 studies used regression analyses, 13,27,28,31,32,35,[37][38][39][40][41][43][44][45][46][47][48][49]51,54,55,…”

“…For example, 23 studies used regression analyses, 13,27,28,31,32,35,[37][38][39][40][41][43][44][45][46][47][48][49]51,54,55,57,58 6 studies used both regression analyses and questionnaires, 3,26,36,52,59,61 3 studies used questionnaires only 29,53,56 ; separate studies used inhaler technique evaluation and regression analyses, 34 assessment of acoustic recordings and regression analyses, 33 inhaler technique evaluation, 60 and interviews and regression analyses. 30 Additionally, 2 studies compared the differences between adherence rates of different drugs. 42,50 Regarding barriers to adherence, the presence of depression was identified as one of the potential barriers to adherence.…”

“…26,36,44,46,48,54,56,58 Concern about the side effects or harmful effects of medicines was reported in 7 studies associated with lower treatment adherence, 3,28,47,53,57,58,61 followed by smoking (no. = 5), 3,30,43,56,57 forgetfulness (no. = 4), 3,26,36,53 presence of comorbid conditions (no.…”

“…3,13,26,[28][29][30][31][34][35][36][37][38][39][41][42][43][44][45][50][51][52]54,57,59 Four of these studies highlighted that the patient's belief in the medication is an essential factor to enhance medication adherence. 26,28,30,59 Subjects had greater adherence when they had a better understanding of their disease and drug therapy. 36,59 Two studies reported that subjects' confidence in health care professionals' expertise was a facilitator to medication adherence.…”