Interaction between depressive symptoms and social support on frailty risk among patients with chronic heart failure

Background Frailty is highly prevalent among patients with chronic heart failure (CHF). Depressive symptoms and social support are significant psychosocial factors associated with frailty, yet how they interact to jointly relate to frailty remains insufficiently explored. Objective This study aimed to investigate the interaction effect between depressive symptoms and social support on the presence of frailty in patients with CHF, to inform the development of targeted intervention strategies. Methods A cross-sectional study was conducted among 380 patients with CHF from a tertiary hospital in Nanning, China. Data were collected using a general information questionnaire, the Patient Health Questionnaire-9 (PHQ-9), the Social Support Rating Scale (SSRS), and the FRAIL Scale. Logistic regression and interaction analyses were performed to evaluate correlations and interactions. Results The prevalence of frailty was 41.3%. Logistic regression analysis identified depressive symptoms (odds ratio [OR] = 7.37, 95% confidence interval [CI]: 4.29–12.63) and low social support (OR = 5.88, 95% CI: 3.57–10.00) as associated factors for frailty (both P < 0.01). A significant multiplicative interaction was observed (OR = 0.23, 95% CI: 0.08–0.66, P = 0.007). Additive interaction analysis further confirmed a synergistic effect (relative excess risk due to interaction [RERI] = 19.19, 95% CI: 9.64–46.94; attributable proportion [AP] = 0.84, 95% CI: 0.72–0.92; synergy index [S] = 8.29, 95% CI: 4.19–37.19). Conclusion Depressive symptoms and social support were significantly associated with frailty, and their interaction demonstrated a synergistic pattern. Longitudinal studies are warranted to explore the temporal nature of these associations. However, the single-center, regional, and male-predominant nature of the sample limits generalizability.