Hypothetical Interventions on Frailty Heterogeneous Trajectories of Older Patients with Gastric Cancer Using Parametric G-Formula.

[BACKGROUND] Frailty is prevalent in older patients with gastric cancer, seriously affecting their prognosis. The time-varying nature of frailty increases the difficulty of intervention. This study aimed to estimate the effect of hypothetical interventions on the risk of frailty heterogeneous trajectory (FHT) at physical, psychological, familial, and social levels to provide a basis for the subsequent design of intervention programs of FHT.

[PATIENTS AND METHODS] The data of hypothetical interventions from a longitudinal follow-up study of older patients with gastric cancer were obtained for 381 patients ≥ 60 years complete at admission, discharge, 1, 3, 6, and 12 months after surgery. The parametric g-formula was used to estimate the risk of single hypothetical interventions on nutrition, anxiety, depression, family cohesion and adaptability, social objective and subjective support, and nursing satisfaction, and its joint interventions in different combinations, for FHT, which were compared with observations to calculate population risk ratios and to determine the optimal combination of interventions.

[RESULTS] The observed risk of FHT was 43.57%. Single intervention on nutrition was the most effective factor in reducing the risk of FHT, with a risk ratio (RR) of 0.790 (95% confidence interval (CI) 0.692-0.974), followed by family cohesion (RR 0.810, 95% CI 0.741-0.917), social objective support (RR 0.822, 95% CI 0.724-0.931), anxiety (RR 0.864, 95% CI 0.681-0.981), and nursing satisfaction (RR 0.967, 95% CI 0.932-0.995). All joint interventions significantly reduced the risk of FHT. Among them, the "all-factors" joint intervention reduced the risk by 31.26%, with an RR of 0.323 (95% CI 0.208-0.685).

[CONCLUSIONS] Hypothetical interventions on nutrition, anxiety, family cohesion, social objective support, and nursing satisfaction reduced the risk of FHT in older patients with gastric cancer, both independently and jointly. This suggests that the interventions targeting these factors, as well as any combination of these interventions, may be effective program for improving the FHT in older patients with gastric cancer. It provides theoretical basis and practical guidance for the frailty intervention and is of practical significance for promoting cancer rehabilitation.

[TRIAL REGISTRATION] The study was registered with clinicaltrials.gov (NCT05982899). https://clinicaltrials.gov/ct2/show/NCT05982899 .