Effect of Prehabilitation on the 6-Minute Walk Test and Length of Hospital Stay in Frail Older People: A Meta-Analysis of Randomized Controlled Trials

Frailty reduces resilience to surgical stress, increasing vulnerability to adverse outcomes. While recovery efforts traditionally focus on the postoperative phase, the preoperative period offers better opportunities for lifestyle interventions. Prehabilitation aims to increase functional reserve and surgical tolerance, especially in frail older adults. This systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated the effectiveness of multimodal prehabilitation on aerobic capacity—measured by the 6 min walk test (6MWT)—and the length of hospital stay (LOS). A literature search was conducted up to August 2025. Eligible RCTs reported the effects of prehabilitation on functional capacity and LOS. A pairwise meta-analysis was used to calculate pooled mean differences (p-MDs) with 95% confidence intervals (CIs). The risk of bias was assessed via the Cochrane RoB tool, and evidence quality was assessed via the GRADE system. Five studies involving 400 participants were included. The p-MD for the 6MWT showed no significant improvement at any time point: (T1–T2) 9.71 (CI: −38.92; 58.36), (T2–T3) −3.27 (CI: −71.21; 64.65), and (T1–T3) 15.01 (CI: −22.05; 52.07). The LOS was also not significantly reduced (p-MD: −0.464, CI: −0.960; 0.031). Prehabilitation did not significantly improve aerobic capacity or reduce hospital stay. Future research should explore long-term benefits and adherence.