Frailty as a Surgical Vital Sign: A Narrative Review of Risk Stratification and Outcomes in General Surgery

Frailty has emerged as a critical determinant of perioperative risk, yet it remains underutilized in routine surgical assessment. As the global population ages, an increasing proportion of patients undergoing general surgery present with diminished physiologic reserve that is not adequately captured by traditional risk stratification tools. This narrative review examines frailty as a multidimensional construct and its role as a prognostic marker in general surgery, with the aim of synthesizing current evidence on its biological basis, evaluating commonly used frailty assessment tools, and examining its impact on postoperative outcomes, including morbidity, mortality, length of stay, and discharge disposition. A comprehensive literature search was conducted using PubMed and Google Scholar to identify relevant peer-reviewed studies published between 2005 and 2025, with an emphasis on surgical populations and clinically validated frailty assessment tools. Across surgical populations, frailty demonstrates strong independent associations with adverse outcomes and has been reported in multiple studies to outperform chronological age and conventional metrics such as the American Society of Anesthesiologists (ASA) classification or comorbidity burden. Among the tools evaluated, instruments such as the Clinical Frailty Scale and Risk Analysis Index demonstrate feasibility for integration into perioperative workflows, while more comprehensive instruments provide additional physiologic granularity when resources permit. Despite variability in assessment methodologies, the collective evidence supports frailty as a robust predictor of surgical vulnerability. Despite variability in assessment methodologies, the collective evidence supports frailty as a robust predictor of surgical vulnerability. Incorporating frailty into routine preoperative evaluation may enhance risk stratification, inform shared decision-making, and guide targeted perioperative optimization strategies. Future efforts should focus on standardization of screening protocols, integration into existing risk calculators, and prospective evaluation of frailty-guided interventions.