Association between frailty and clinical outcomes in surgical patients admitted to intensive care units: a systematic review and meta-analysis

Background: Preoperative frailty may be a strong predictor of adverse postoperative outcomes. We investigated the association between frailty and clinical outcomes in surgical patients admitted to the ICU. Methods: PubMed, Embase, and Ovid MEDLINE were searched for relevant articles. We included full-text original English articles that used any frailty measure, reporting results of surgical adult patients (≥18 yr old) admitted to ICUs with mortality as the main outcome. Data on mortality, duration of mechanical ventilation, ICU and hospital length of stay, and discharge destination were extracted. The quality of included studies and risk of bias were assessed using the Newcastle Ottawa Scale. Data were synthesised according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Results: Thirteen observational studies met inclusion criteria. In total, 58 757 patients were included; 22 793 (39.4%) were frail. Frailty was associated with an increased risk of short-term (risk ratio [RR]=2.66; 95% confidence interval [CI]: 1.99–3.56) and long-term mortality (RR=2.66; 95% CI: 1.32–5.37). Frail patients had longer ICU length of stay (mean difference [MD]=1.5 days; 95% CI: 0.8–2.2) and hospital length of stay (MD=3.9 days; 95% CI: 1.4–6.5). Duration of mechanical ventilation was longer in frail patients (MD=22 h; 95% CI: 1.7–42.3) and they were more likely to be discharged to a healthcare facility (RR=2.34; 95% CI: 1.36–4.01). Conclusion: Patients with frailty requiring postoperative ICU admission for elective and non-elective surgeries had increased risk of mortality, lengthier admissions, and increased likelihood of non-home discharge. Preoperative frailty assessments and risk stratification are essential in patient and clinician planning, and critical care resource utilisation. Clinical trial registration: PROSPERO CRD42020210121.