Drug therapy problems and contributing factors in the management of heart failure patients in Jimma University Specialized Hospital, Southwest Ethiopia

BACKGROUND: Drug therapy problem (DTP) is any unwanted incident related to medication therapy that actually or potentially affects the desired goals of treatment. Heart failure (HF) patients are more likely to experience DTP owing to multiple prescriptions and comorbidities. Despite the serious negative impact of DTP on treatment outcomes, there is a dearth of study on DTP among HF patients in Ethiopia. OBJECTIVE: The main aim of this study was to assess the prevalence and contributing factors of DTP among ambulatory HF patients in Jimma University Specialized Hospital, Ethiopia. METHODS: A hospital based prospective observational study was conducted. Written informed consent was obtained from each patient after full explanation of the study. Data were collected through patient interview and expert review of medical, medication and laboratory records of one-year follow-up from May 2015 to April 2016. DTPs were identified using Cipolle’s method followed by consensus review with experts. Binary logistic regression was performed to identify factors contributing to DTP. A p<0.05 was considered statistically significant in all analyses. RESULT: Of 340 study participants; male to female ratio was equivalent, the mean (± SD = standard deviation) age was 50.5±15.6 years. Eight hundred eighty DTPs were identified equating 2.6 ±1.8 DTPs per patient. The frequently identified DTPs were dosage too low (27.8%), ineffective drug therapy (27.6%) and need additional drug therapy (27.4%). Most commonly implicated drugs were beta-blockers (34.4%), angiotensin converting enzyme inhibitors (24.8%), statins (16.5%) and antithrombotics (13.1%). Factors contributing to DTP were age >50 years (AOR [adjusted odd ratio] = 5.43, 95%CI [95% confidence interval] = 2.03–14.50); negative medication belief (AOR = 3.50, 95%CI = 1.22–10.05); poor involvement of patients in the therapeutic decision makings (AOR = 4.11, 95%CI = 1.91–8.88); number of co-morbidity≥2(AOR = 5.26, 95%CI = 2.38–11.65) and number of medications ≥5 (AOR = 3.68, 95%CI = 1.28–10.51). CONCLUSION: DTPs are common among ambulatory care HF patients. Patients with older age, negative medication belief, polypharmacy, co-morbidities and those who were poorly involved in the therapeutic decision were more likely to experience DTP. Despite traditional prescription refilling, an integrated multidisciplinary approach involving patients and clinically trained pharmacists should be implemented in the patient care process at ambulatory care clinics in order to improve overall outcomes and reduce DTPs and associated burdens in HF patients.