January 16, 2017
Although COPD can be well managed with the use of several medications to prevent and control symptoms and exacerbations, adherence levels for COPD medications have been found to be lower than the levels typically observed for treatments for other conditions. Previously established reasons for low medication adherence for COPD are daily variations in symptoms, patient knowledge and beliefs, socioeconomic factors, and other comorbidities among patients.
Patients with COPD typically have multiple chronic comorbidities including conditions such as hypertension, coronary atherosclerosis, other heart diseases, lipid disorders, diabetes, osteoporosis, and sleep apnea. Therefore, researchers sought to investigate whether non-adherence to maintenance COPD (mCOPD) medications was associated with similar non-adherence to non-COPD medications in patients with COPD.
Researchers examined claims from the Humana Research Database from January 1, 2008, to December 31, 2012, for patients who initiated mCOPD medication within 1 year of diagnosis. Adherence to mCOPD medications was measured in terms of proportion of days covered (PDC). For the same patients, adherence to each of the following 12 non-COPD medication classes was measured: statins, antihypertensives, anticoagulants, oral antihyperglycemix, insulins, antidepressants, nonsteroidal anti-inflammaotry medications (NSAIDS), antianxiety, calcium channel blockers, beta-blockers, bisphosphonates, and diuretics.
The results of the study show that less than one-fourth (20.8%) of patients were considered adherent, based on a PDC threshold of 0.8. The researchers found similarly low adherences for other medications: the mean PDC for mCOPD medications was 0.47, whereas mean PDC for the non-COPD medication classes examined ranged from 0.33 to 0.71.
Multivariate analyses showed independent associations between nonadherence to MCOPD medications and each of the other medications examined. “This finding implies that adherence to medications may be impacted by factors such as health system-related factors, patient-related factors, and socioeconomic factors that do not change by disease or medication type,” concluded the authors of the study. Statistically significant differences were found between adherent and non-adherent patients in terms of geographical location, comorbidity burden, and influenza vaccine status.
“Since our study findings imply that factors that do not change by medication type may be impacting adherence, more widespread use of patient counseling tools, such as motivational interviewing by pharmacists and other health care providers, may be able to influence patient behavior in improving their adherence irrespective of medication type,” the authors concluded.
—Julie Gould (Mazurkiewicz)
Dhamane AD, Schwab P, Hopson S, et al. Association between adherence to medications for COPD and medications for other chronic conditions in COPD patients [published online December 22, 2016]. Int J COPD. 2016; 2017(12): 115-122. DOI https://doi.org/10.2147/COPD.S114802.