Cost-effectiveness of prehabilitation for elderly (pre-)frail patients prior to elective surgery compared to standard care - an economic evaluation from a societal perspective

Background Frailty syndrome is highly prevalent among elderly surgical patients, increasing their risk of experiencing perioperative complications and developing long-term disability. Prehabilitation may reduce these risks by optimising patients’ physiological reserves prior to surgery. The PRAEP-GO trial, a multicentre randomised controlled outcome assessor-blinded trial conducted in Germany, evaluated the (cost-)effectiveness of prehabilitation for older (pre-)frail patients undergoing elective surgery compared to standard care. Methods The economic evaluation comprised (i) a cost-utility analysis with the quality-adjusted life year (QALY) as the outcome and (ii) a cost-effectiveness analysis. The latter used the change in level of care dependency from baseline to 12 months postoperatively (deterioration versus no deterioration) as the primary effect measure and the WHO Disability Assessment Schedule (WHODAS 2.0) at 12 months as secondary effect measure. We calculated incremental cost-effectiveness ratios (ICERs) and determined the probability of cost-effectiveness at arbitrary willingness-to-pay thresholds. The main analysis was an intention-to-treat analysis. Additionally, we performed complete case, per-protocol and sensitivity analyses as well as subgroup analyses. Results The cost-utility analysis yielded an ICER of 45,547 EUR per QALY gained, indicating a 52% probability of cost-effectiveness at a willingness-to-pay of 50,000 EUR. The cost-effectiveness analysis yielded an ICER of 27,197 EUR per patient with a deterioration in care dependency level prevented, with a 69% probability of being cost-effective at 50,000 EUR. Regarding the QALY, the probabilities were higher in the per-protocol analyses, which included patients who received at least 15 sessions of prehabilitation and those who additionally underwent the planned surgery. The cost-effectiveness analysis based on the WHODAS 2.0 yielded an ICER of 1,241 EUR per point gained. Subgroup analyses revealed that the intervention is cost-effective for patients who received prehabilitation in an outpatient setting compared to a propensity-score matched control. Conclusions The intervention was found to be more effective, but also more costly than standard preoperative care. Cost-utility was higher when the intervention was completed as intended. It may be cost-effective in patients who received prehabilitation in an outpatient setting. Future efforts should therefore prioritise optimising adherence and ensuring effective outpatient delivery. Trial registration Economic evaluation: OSF Registries (osf.io/ecm74), PRAEP-GO trial: ClinicalTrials.gov (NCT04418271).