Effect of a WeChat Intervention Based on the Common-Sense Model on Breast Cancer-Related Lymphedema Preventive Behaviors: Quasi-Experimental Study.

[BACKGROUND] Breast cancer-related lymphedema is the most prevalent postoperative complication among breast cancer survivors. Although mobile health tools are increasingly used for patient education, evidence supporting their efficacy in lymphedema prevention remains limited.

[OBJECTIVE] This study aimed to evaluate the effectiveness of a WeChat-based intervention grounded in the common-sense model (CSM) in improving preventive behaviors, modifying illness perceptions, and reducing lymphedema incidence among breast cancer survivors and to validate the targets of the intervention.

[METHODS] This study used a quasi-experimental design. Participants (N=192) were recruited from the breast cancer department of a cancer hospital in Guangzhou, China. The control group (n=98) received routine care. The intervention group (n=94) participated in a 3-month CSM-guided WeChat mini-program ("Nantian e-Care") delivering tailored educational articles, exercise tutorials, arm circumference monitoring, and real-time nurse consultations. Outcomes, including preventive behaviors, illness perceptions, and lymphedema incidence, were assessed 1, 3, and 6 months post surgery. Generalized estimating equations were used for the analysis.

[RESULTS] The intervention group exhibited significant improvements in lifestyle adjustments (Wald χ22=6.9, P=.03) and physical exercise adherence (Wald χ22=6.9, P=.03) compared with the control group. Illness perception, including identity (Wald χ23=8.1, P=.04), timeline cyclical (Wald χ23=8.5, P=.04), personal control (Wald χ23=9.3, P=.03), illness coherence (Wald χ23=29.8, P<.001), and behavioral (Wald χ23=19.5, P<.001) and physical factors (Wald χ23=24.1, P<.001) were markedly enhanced. Mechanistically, skin care improvements were driven by intervention effects, personal control, illness coherence, and behavioral attribution. Lifestyle changes were correlated with intervention and illness coherence. Adherence to physical exercise was not statistically significantly affected by the intervention, although a trend was observed. Critically, the intervention group demonstrated a lower incidence of lymphedema at 6 months (7.50% vs 16.48%, χ21=3.9, P=.048).

[CONCLUSIONS] The CSM-guided WeChat intervention effectively promoted preventive behaviors, optimized illness perceptions, and reduced lymphedema risk. These findings underscore the value of integrating theory-driven mobile health tools into postoperative care and highlight scalable strategies for chronic disease management in resource-limited settings.