Assessment of medication adherence in patients with Type 2 Diabetes and arterial hypertension: medication adherence in chronic disease

Abstract

Aims: Assessment of medication adherence in newly diagnostic and treated patients with Type 2 Diabetes Mellitus and Arterial Hypertension, in the Primary Health Care Units of Lisbon and Tagus Valley. Methods: This is an observational and retrospective cohort study. The population is composed of newly diagnosed patients with Type 2 Diabetes Mellitus and Arterial Hypertension, at the beginning of treatment. Data was extracted from the Lisbon and Tagus Valley Regional Health Administration Information System. Medication adherence was assessed in three periods: patients started therapy or not after the professional's prescription (initiation); medication possession rate during the follow-up period (MPR) (implementation) and medication discontinuation, marks the end of therapy (discontinuation). Results: An initiation rate of 84.2% was obtained in patients with both diseases (98% for oral antidiabetic therapy and 84.6% for antihypertensive therapy). The implementation rates (MPR) for both diseases was only 3.4% (4.2% were considered adherent to oral antidiabetic therapy and 8.5% to antihypertensive therapy). The discontinuation rate was 3.4% (5.5% for oral antidiabetic therapy and 13.2% for antihypertensive therapy). Most patients initiate taking drugs after prescription but very few patients have a MPR enough to consider them having good adherence. Moreover, few patients discontinue the medication. Conclusions: Patients had a higher implementation rate to antihypertensive therapy but, on the other hand, were more persistent to the oral antidiabetic therapy. Through this new assessment, the medication adherence pattern seems to be influenced by the patient and by the disease itself.