Impact of early mobilization on long-term mortality following fast-track hip fracture surgery: a retrospective cohort study.

BACKGROUND: Hip fractures in older adults are associated with mortality risk despite advances in perioperative care. Although early mobilization improves short-term outcomes, its effect on long-term survival remains uncertain. OBJECTIVES: To evaluate the association between early postoperative mobilization and long-term mortality in older adults undergoing fast-track hip fracture surgery. METHODS: This retrospective cohort study included participants aged ≥60 years treated within a Hip Fast-Track Surgery program between 2018 and 2024. Participants were classified as early (≤24 h) or late (>24 h) mobilization. Stabilized inverse probability of treatment weighting (sIPTW) was employed to adjust for baseline characteristics and postoperative complications. Mortality was ascertained via the National Civil Registry. Survival was analyzed using Kaplan-Meier methods and Cox proportional hazards models. RESULTS: Among 680 participants (early mobilization: n = 214; late mobilization: n = 466) with a median follow-up of 2.41 years, early mobilization was associated with higher survival (log-rank, P < 10-3). No deaths were observed in the early mobilization group during hospitalization or within 6 months. After sIPTW adjustment, early mobilization was associated with a 94% reduction in 1-year mortality (adjusted HR 0.06; 95% CI, 0.01-0.41; NNT = 8) and a 61% reduction in overall mortality (adjusted HR 0.39; 95% CI, 0.22-0.70; NNT = 4). Adjusted postoperative length of stay did not differ between groups. CONCLUSIONS: Early mobilization within 24 h after fast-track hip fracture surgery is associated with substantial reductions in short- and long-term mortality in older adults. Given the observational design and substantial residual confounding, findings should be interpreted as hypothesis-generating associations rather than causal effects. TRIAL REGISTRATION: Thai Clinical Trials Registry; TCTR20260201009.