RESUMEN
OBJECTIVE: To evaluate the effectiveness of motivational interviewing (MI) in improving medication adherence in older patients being treated by polypharmacy. METHODS: Cluster randomized clinical trial in 16 primary care centers with 27 health care providers and 154 patients. Thirty-two health care providers were assigned to an experimental (EG) or control group (CG). INTERVENTIONS: MI training program and review of patient treatments. Providers in the EG carried out MI, whereas those in the CG used an "advice approach". Three follow-up visits were completed, at 15 days and at 3 and 6 months. Medication adherence in both groups was compared (p<0.05). RESULTS: Patients recruited: 70/84 (EG/CG). Mean age: 76 years; female: 68.8%. The proportion of subjects changing to adherence was 7.6% higher in the EG (p<0.001). Therapeutic adherence was higher for patients in the EG (OR=2.84), women (OR=0.24) and those with high educational levels (OR=3.93). CONCLUSION: A face-to-face motivational approach in primary care helps elderly patients with chronic diseases who are being treated by polypharmacy to achieve an improved level of treatment adherence than traditional strategies of providing information and advice. PRACTICE IMPLICATIONS: MI is a patient-centered approach that can be used to improve medication adherence in primary care. TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov (NCT01291966).