Methods: A cross-sectional data analysis of each time phase of the parent study “Community-based intervention to promote self-management for rural dwelling older people with hypertension: mixed method study”. The study settings comprised of residents in 17 villages, and were users of the primary health care center in Nakhon Ratchasima Province, Thailand. All participants were separated into two groups based on geographical area and allocated into the intervention and the control group through a simple random technique. Both groups received routine care and a self-management tool kit. In addition, the intervention group received the four-week community-based intervention program which contained group activities, individual home visits by researcher. Multiple linear regression was applied to predict adherence status at each phase followed by stepwise regression with backward selection technique to select significant predictors. After 6 month, patients were categorized into improved and non-improved adherence status. Parametric and non-parametric were applied to compare general characteristics between groups. Then, multiple logistic regression was implemented to predict influencing factors between groups followed by a model selection using using Akaike information criterion (AIC) with forward selection technique.
Results: A sample of 156 elderly with hypertension, 70 years old on average and mostly female (68.5%). 77 (49.36%) participants attended a community-based intervention. Patients who received intervention had significant lower adherence score (a higher score reflects a lower level of adherence) at 3 and 6 months after intervention by 1.66 points (95%CI 0.61-2.71, p<0.001), and 1.45 points (95%CI 0.47-2.42, p<0.001) respectively when adjusting other variables. Moreover, women had a statistically significantly lower adherence score than men at baseline and 3 months after intervention, patients with other comorbidities had significant lower adherence score than patients with hypertension only at all follow-up period. After six month from baseline, there were 74 (47.44%) participants who had improved adherence status. The community-based intervention was associated with a significant improvement in adherence adjusted for other variables (odds ratio = 2.65 [95% CI 1.32–5.35], P=0.006). The decreasing of waist circumference demonstrated a trend in improved adherence (odds ratio = 1.85 [95% CI 0.91–3.77], P=0.09). The final model that impacted on improve adherence by forward selection with AIC comprised of intervention, decreasing of waist circumference and marital status (LR chi2 (4) =15.98, P=0.003, AIC=209.87)
Conclusion: This study provides evidence to support the use of community-based intervention as an effective adjunct to hospital-based care of patients with hypertension. Understanding the influencing factors between health outcomes and social determinants of health is critical for informing intervention development.