Association between Patient Frailty and Postoperative Mortality across Multiple Noncardiac Surgical Specialties

Importance: Frailty is an important risk factor for postoperative mortality. Whether the association between frailty and mortality is consistent across all surgical specialties, especially those predominantly performing lower stress procedures, remains unknown. Objective: To examine the association between frailty and postoperative mortality across surgical specialties. Design, Setting, and Participants: A cohort study was conducted across 9 noncardiac specialties in hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) and Veterans Affairs Surgical Quality Improvement Program (VASQIP) from January 1, 2010, through December 31, 2014, using multivariable logistic regression to evaluate the association between frailty and postoperative mortality. Data analysis was conducted from September 15, 2019, to April 30, 2020. Patients 18 years or older undergoing noncardiac procedures were included. Exposures: Risk Analysis Index measuring preoperative frailty categorized patients as robust (Risk Analysis Index ≤20), normal (21-29), frail (30-39), or very frail (≥40). Operative Stress Score (OSS) categorized procedures as low (1-2), moderate (3), and high (4-5) stress. Specialties were categorized by case-mix as predominantly low intensity (>75% OSS 1-2), moderate intensity (50%-75%), or high intensity (<50%). Main Outcomes and Measures: Thirty-day (both measures) and 180-day (VASQIP only) postoperative mortality. Results: Of the patients evaluated in NSQIP (n = 2339031), 1309795 were women (56.0%) and mean (SD) age was 56.49 (16.4) years. Of the patients evaluated in VASQIP (n = 426578), 395761 (92.78%) were men and mean (SD) age was 61.1 (12.9) years. Overall, 30-day mortality was 1.2% in NSQIP and 1.0% in VASQIP, and 180-day mortality in VASQIP was 3.4%. Frailty and OSS distributions differed substantially across the 9 specialties. Patterns of 30-day mortality for frail and very frail patients were similar in NSQIP and VASQIP for low-, moderate-, and high-intensity specialties. Frailty was a consistent, independent risk factor for 30- and 180-day mortality across all specialties. For example, in NSQIP, for plastic surgery, a low-intensity specialty, the odds of 30-day mortality in very frail (adjusted odds ratio [aOR], 27.99; 95% CI, 14.67-53.39) and frail (aOR, 5.1; 95% CI, 3.03-8.58) patients were statistically significantly higher than for normal patients. This was also true in neurosurgery, a moderate-intensity specialty, for very frail (aOR, 9.8; 95% CI, 7.68-12.50) and frail (aOR, 4.18; 95% CI, 3.58-4.89) patients and in vascular surgery, a high-intensity specialty, for very frail (aOR, 10.85; 95% CI, 9.83-11.96) and frail (aOR, 3.42; 95% CI, 3.19-3.67) patients. Conclusions and Relevance: In this study, frailty was associated with postoperative mortality across all noncardiac surgical specialties regardless of case-mix. Preoperative frailty assessment could be implemented across all specialties to facilitate risk stratification and shared decision-making.