BACKGROUND: Surgery carries inherent risks, with the postoperative phase being as critical as the intraoperative period. Enhanced perioperative care units, positioned between general wards and intensive care units, aim to provide adequate postoperative management and resource allocation. Despite their widespread implementation, evidence on outcomes remains limited. OBJECTIVES: The primary outcome was 30-day or in-hospital mortality following extended postoperative recovery, with subgroup meta-analysis examining enhanced perioperative care units and intensive care units. Secondary outcomes included, among others, hospital length of stay. DESIGN: Systematic review with meta-analysis. DATA SOURCES: A comprehensive search was conducted in MEDLINE, Embase, Web of Science, Cochrane Central, and Google Scholar from inception up to 22 April 2024. ELIGIBILITY CRITERIA: The search string encompassed extended postoperative recovery units, including enhanced perioperative care units and intensive care units, for noncardiac, nontransplant surgery, excluding speciality-specific, age-specific, indirect and nonsurgical admissions. Two reviewers independently conducted screening, eligibility assessment and quality appraisal. RESULTS: Of 28 179 records screened, 24 were included of which 22 were unique studies. The overall pooled random-effects mortality, based on 15 studies, was 3 (95% confidence interval (CI) 2 to 6)%. Subgroup analysis demonstrated a mortality of 2 (95% CI 1 to 4)% for patients managed in enhanced perioperative care units and 8 (95% CI 4 to 14)% in intensive care units ( χ2 = 7.99
P <
0.01). Risk of bias (ROBINS I) was moderate to serious, and heterogeneity substantial. Pooled hospital length of stay, based on six studies, was 8.6 (95% CI 5.9 to 11.3) days. CONCLUSION: Pooled mortality following extended postoperative recovery in noncardiac surgery was 3% (95% CI 2 to 6). Subgroup analysis indicated lower mortality among patients managed in enhanced perioperative care units. However, considerable heterogeneity in operational definitions, unit capabilities, and admission criteria necessitates cautious interpretation while reflecting real-world practices. Delineation through further research is warranted. PROSPERO REGISTRATION: CRD42023457051.