Frailty Status as a Predictor of Outcomes in Emergency Surgeries for Older Adults: A Systematic Review and Meta-Analysis

Abstract

The global aging population has brought increasing attention to frailty as a critical predictor of health outcomes. Defined by the British Geriatric Society as a state of diminished physiological reserve across multiple systems, frailty reflects a heightened vulnerability to adverse events. While the negative impact of frailty is well established in elective surgical settings, its influence on outcomes following emergency abdominal surgery remains less clear. This meta-analysis evaluates postoperative outcomes in frail versus non-frail elderly patients undergoing emergency abdominal surgery. A comprehensive search of eight electronic databases was conducted from inception to January 2024, with an additional search in June 2024. Eligible studies were selected based on predefined inclusion criteria. The primary outcome was postoperative mortality, with secondary outcomes, including complications, length of hospital stay, discharge destination, readmission, and reoperation rates. Data were synthesized using RevMan5 (Cochrane Collaboration, London, UK) and R (R Development Core Team, Vienna, Austria), applying both fixed and random-effects models. Risk of bias in individual studies was assessed using the Quality in Prognostic Studies (QUIPS) tool. Thirty-one studies involving 1,750,195 participants were included. Frail patients showed significantly increased 30-day (OR: 2.83, 95% CI: 2.45-3.27; p<0.00001) and 12-month (OR: 1.97, 95% CI: 1.32-2.93; p=0.0008) mortality. They also experienced higher overall morbidity, more severe complications (Clavien-Dindo ≥3: OR: 2.39, 95% CI: 1.82-3.13; p<0.00001), longer hospital stays (WMD: 3.74 days, 95% CI: 1.54-5.94; p=0.0008), and increased rates of readmission and reoperation (OR: 1.48, 95% CI: 1.25-1.75; p<0.00001). Discharge to rehabilitation or skilled nursing facilities was also more common among frail patients. These findings demonstrate that frailty significantly worsens postoperative outcomes in elderly patients undergoing emergency abdominal surgery. Further research is warranted to explore the integration of frailty assessment tools in emergency settings to support surgical decision-making for this vulnerable population.

Keywords: acute abdominal surgery; complications; elderly patients; emergency surgery; frailty; mortality.

Figure 1. PRISMA flowchart

PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses

Figure 2. Risk of bias of studies using the QUIPS tool

QUIPS: QUality In Prognosis Studies

Figure 3. Forest plot of the association of frailty with 30-day mortality

References: [24,25,27-31,35-37,39-41,43,44,47,48,51-53]

Figure 4. Forest plot of the association of frailty with 90-day mortality

References: [43,45]

Figure 5. Forest plot of the association of frailty with 180-day mortality

References: [25,39,40]

Figure 6. Forest plot of the association of frailty with 12-month mortality

References: [24,40,42,49,50]

Figure 7. Forest plot of the association of frailty with in hospital mortality

References: [32-34,38,39,46,52,53]

Figure 8. Forest plot of the association of frailty with postoperative complications

References: [28,29,32-35,38,43,45,48,52]

Figure 9. Forest plot of the association of frailty with severity of complications

References: [25,29,33,36,45-48]

Figure 10. Forest plot of the association of frailty with ICU admission

References: [38,42,45,51]

Figure 11. Forest plot of the association of frailty with ICU length of stay

References: [32-34,38,43]

Figure 12. Forest plot of the association of frailty with failure to rescue

References: [28,35,38,52]

Figure 13. Forest plot of the association of frailty with duration of hospital stay

References: [32,33,34,38,40,45,46,48,51,52]

Figure 14. Forest plot of the association of frailty with discharge location. (A) Home (B) Skilled nursing facility (C) Rehabilitation (D) Non-home discharge.

References: [27,32,33,34,38-40,47,48,52]

Figure 15. Forest plot of the association of frailty with re-admission at (A) 30 days and (B) six months

References: [26,27,28,35,38,40,47,48,52]

Figure 16. Forest plots of the association of frailty with re-operation

References: [25,28,33,35,48,51,52]

Figure 17. Funnel plots of publication bias (A) 30-day mortality (B) Postoperative complications (C) Duration of hospital stay.