Purpose: The aim of this study was twofold: 1) To evaluate the effectiveness of MI in reducing blood pressure (BP) in patients with hypertension and 2) to evaluate the effectiveness of MI in improving self-care behaviors.
Design and methods: Single-center, parallel, RCT, blinded to outcome assessment. The study included 120 adult patients diagnosed with hypertension, who receive regular follow-up in an outpatient hypertension clinic during six months. Patients were randomly allocated to two groups: the intervention group (IG) that received MI by a trained nurse, and control group (CG) that received standard care. All patients in the IG and the CG were monitored face-to-face, once a month for six months. Primary outcome was the reduction in systolic blood pressure and changes in the mean blood pressure measured by 24-hour ambulatory blood pressure monitoring. Secondary outcomes included the self-care behaviors measured with the Self-Care of Hypertension Inventory that measure self-care in the dimensions of self-care maintenance (behaviors aimed at BP stability), self-care management (behaviors aimed at responding to high blood pressure levels) and self-care confidence (self-efficacy in managing the self-care process). The outcomes were measured at baseline and at the end of six month follow-up.
Results: The enrolled patients were mostly females (70%) with a mean age of 62 years old (SD=10), white (72%) who suffered from hypertension for = 13 years. No statistically significant differences were between the IG and the CG at baseline characteristics. At baseline, systolic and diastolic BP in the IG were 127.78 and 75.02 mmHg respectively; Systolic and diastolic BP in the CG were 123.36 and 72.82 mmHg respectively (p>0,05 between the groups). At the 6-month follow-up, systolic and diastolic BP in the IG decreased to 121.84 and 70.85 respectively (p<0.001); Systolic and diastolic BP in the CG did not change significantly (p>0.05). Regarding self-care, patients in the IG improved in all dimensions of the self-care (p<0.05), whereas patients in the CG did not (p>0.05).
Conclusion: This RCT has proved that MI is effective in improving BP and self-care in patients with hypertension. Since only few studies have evaluated the effectiveness of MI in improving BP and self-care behaviors in patients with hypertension, further studies are needed in larger and multicenter samples.