Effectiveness of a tailored communication intervention to improve physical activity in hypertensive patients: a twelve-month randomized controlled trial

Background: Cardiovascular diseases (CVDs) are a leading cause of morbidity and mortality globally. Arterial hypertension is one of the main cardiovascular risk factors. Despite this, individuals with hypertension often fail to follow medical advice to counteract cardiovascular risks. A physically active lifestyle is one of the most challenging behaviors to adopt. This study aimed to preliminarily investigate the effectiveness of a tailored print message intervention to increase physical activity in patients with arterial hypertension. Methods: A sample of 188 patients with hypertension (mean age = 63 years; SD = 10.9; 50% men) participated in a theory-based tailored health communication intervention. Participants were randomly assigned to three parallel groups: (1) the tailored group, which received tailored health brochures; (2) the non-tailored group, which received non-tailored health brochures; or (3) the usual care group, which received no informative print materials. The longitudinal physical activity trajectories (baseline, 6- and 12-month follow-ups) were examined using repeated measures ANOVA and growth curve models. Results: At the baseline, 38.8% of patients achieved the target physical activity. This percentage rose to 43.0% at 6-month follow-up and 46.0% at 12-month follow-up. The descriptive statistics divided in function of the experimental group suggested differences in the longitudinal trend of the mean physical activity depending on the experimental group. However, statistical significance using repeated measures ANOVA did not support this observation. The analysis of the growth curves suggested that the tailored group showed a progressive increase in physical activity over twelve months (the model that best described the longitudinal trajectory was a linear growth model). The non-tailored group showed an increase in physical activity six months after the beginning of the intervention, followed by a decrease (free time score model). The usual care group did not change over time (no-growth model). Conclusions: Findings suggest the effectiveness of the tailored intervention proposed. However, further investigations and empirical confirmations are required. Trial registration: ISRCTN13415993 (https://doi.org/10.1186/ISRCTN13415993). Registration date: 08/04/2019.