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 (