The Prevalence of Frailty and Its Non‐Linear Associations With Depressive Symptoms Among Cancer Survivors: A Multicenter Study With Network Analyses

OBJECTIVE: Frailty and depressive symptoms frequently co-occur in cancer survivors. However, large multicenter studies exploring their non-linear patterns and symptom-level links are limited. This study examined the prevalence of frailty and its non-linear and symptom-level relationships with depressive symptoms among hospitalized adult cancer survivors. METHODS: A multicenter cross-sectional survey, conducted in May-December 2025, recruited 9224 hospitalized adult cancer survivors from oncology departments across seven regions in China. We assessed frailty with the FRAIL scale and depressive symptoms with the PHQ-9. Multivariable logistic regression estimated the adjusted associations between depressive symptoms and pre-frailty (FRAIL ≥ 1) and frailty (FRAIL ≥ 3). Restricted cubic spline and two-piecewise linear models examined their non-linear relationships. A regularized partial correlation (EBICglasso) network including the FRAIL score and nine PHQ-9 items was used to identify symptom-level connections. RESULTS: The Prevalence of pre-frailty and frailty was 35.7% (95% CI: 34.7%-36.7%) and 12.7% (95% CI: 11.9%-13.5%), respectively. Each 1-point increase in PHQ-9 score was associated with higher odds of pre-frailty (OR = 1.19; 95% CI: 1.18-1.21) and frailty (OR = 1.14; 95% CI: 1.13-1.16). Non-linear patterns showed steeper increases in the odds of pre-frailty and frailty below PHQ-9 total scores of 6.87 and 8.33, respectively. Fatigue (PHQ-4), poor appetite (PHQ-5), and psychomotor changes (PHQ-8) were the symptoms that were most strongly linked to frailty. CONCLUSIONS: The study found that pre-frailty and frailty were common among hospitalized cancer survivors. Both had strong non-linear associations with depressive symptoms, even at mild levels. The findings support routine screening for frailty and depressive symptoms and highlight the potential importance of key somatic symptoms in this sub-population.