ABSTRACT
INTRODUCTION: Motivational interviewing is an effective style of collaborative communication for the promotion of lifestyle changes in the management of Type 2 diabetes and arterial hypertension. This study evaluates the effectiveness of motivational interviewing in the management of these conditions in primary health care. STUDY DESIGN: This study is a double-blind parallel-group RCT performed between June 2018 and July 2019. SETTING/PARTICIPANTS: The RCT was conducted in Porto Alegre, Rio Grande do Sul, Brazil, and included individuals with Type 2 diabetes and arterial hypertension. INTERVENTION: The participants were randomized to the test/motivational interviewing and usual care groups. The test/motivational interviewing group received the nursing consultation intervention on the basis of motivational interviewing conducted by professionals with 20 hours of training, and the usual-care group received conventional nursing consultation. MAIN OUTCOME MEASURES: The main outcome measure was the mean difference in HbA1c. The secondary outcome measures were the mean differences in blood pressure and adherence levels. RESULTS: After a mean follow-up of 6 months, 174 participants completed the study (usual-care group=80; test/motivational interviewing group=94). There were statistically significant differences between the groups, with improvement in the test/motivational interviewing group for systolic blood pressure (p<0.01), diastolic blood pressure (p<0.01), and total adherence score as measured by the Martín-Bayarre-Grade questionnaire (p=0.01) and its operational dimensions of treatment adherence and personal involvement (p=0.03, p=0.03). The test/motivational interviewing group showed significantly reduced HbA1c levels (0.4%) at the end of the study (p<0.01). CONCLUSIONS: In the context of primary health care, the nursing consultation based on motivational interviewing was shown to be a more effective care strategy than usual care for improving blood pressure levels and adherence levels in individuals with Type 2 diabetes and arterial hypertension. Moreover, motivational interviewing was demonstrated to be useful in reducing HbA1c levels in diabetes management. TRIAL REGISTRATION: This study is registered at www.clinicaltrials.gov NCT03729323.