Objective: To explore the application of repeated measurement 'analysis of variance' (ANOVA) in evaluating the effectiveness of 'community-based hypertension self-management program'.
Methods: A community-based parallel controlled trial was conducted among 3 communities. 169 patients in intervention group took part in the course on hypertension self-management program once a week and 204 patients in control group received routine hypertension management services. Data collected through questionnaire at baseline and 6 months, 12 months after intervention and were compared through repeated ANOVA measurement.
Results: Subjects in the intervention group showed statistical significance and linear trends in health self-evaluation, distress, in low spirit, self-efficacy in managing symptoms (SEMS), self-efficacy to managing diseases in general (SEMDG), systolic blood pressure (SBP) and diastolic blood pressure (DBP) over time by univariate test of repeated measurement ANOVA. The score of SEMS increased from 6.84 +/- 2.53 at baseline to 8.20 +/- 1.44 at 12 months after intervention while SEMDG from 7.28 +/- 2.45 to 8.89 +/- 1.05, and SBP decreased from 137.66 +/- 7.30 mm Hg (1 mm Hg = 0.133 kPa) to 130.41 +/- 7.71 mm Hg, DBP decreased from 84.13 +/- 6.70 mm Hg to 81.04 +/- 5.98 mm Hg respectively. Only low spirit and SBP changed over time were seen in the control group. Self-evaluation, distress,in low spirit, caused by diseases, SEMS, SEMDG and SBP were statistically different between control and intervention groups, and the effect of interaction between groups and time span were statistically significant on indicators as self-evaluation, low spirit, self-efficacy in managing symptoms, self-efficacy to manage diseases and SBP etc, by multivariate test of repeated measurement ANOVA.
Conclusion: Repeated measurement ANOVA not only could be used to analyze group-effect, but could also explain the effect and the interaction among groups and time, to make the results more reliable. The self-management approach could improve the health status and self-efficacy of the patients,so as to reduce the blood pressure. Our result showed that it was effective for hypertensive patients to be on the chronic diseases self-management program.