Correlates of adherence to respiratory drugs in COPD patients.

Aims: To identify the correlates of accidental omissions and intentional interruptions of respiratory therapy in COPD.

Methods: COPD patients (GOLD stages II-IV) were recruited by general practitioners or respiratory physicians. Patients reported in self-report questionnaires their adherence to respiratory drugs (over the past three months) and their perception of therapy.

Results: 179 patients were included (mean age 63 years, 24% females). 45% forgot their respiratory therapy, while 30% interrupted it in the absence of any perceived benefit. The risks of accidental omissions were significantly higher when patients complained about having too many medications to take on a daily basis (OR=2.35; 95%CI=1.13-4.89), and among current smokers (OR=2.14; 95%CI=1.07-4.29). Females were more likely to interrupt therapy intentionally (OR=2.40; 95%CI=1.04-5.53). Surprisingly, there was no significant relationship with the number of drugs actually taken by patients.

Conclusions: Adherence to respiratory drugs is inadequate in COPD patients. In order to improve adherence, patients' perception of the burden of therapy should not be overlooked.