Impact of peri‐operative frailty and operative stress on post‐discharge mortality, readmission and days at home in Medicare beneficiaries

Summary Background Understanding how patients' frailty and the physiological stress of surgical procedures affect postoperative outcomes may inform risk stratification of older patients undergoing surgery. The objective of the study was to examine the association of peri‐operative frailty with mortality, 30‐day readmission and days at home after non‐cardiac surgical procedures of different physiological stress. Methods This retrospective study used Medicare claims data from a 7.125% random sample of Medicare fee‐for‐service beneficiaries from 2015 to 2019 who were aged ≥ 65 years and underwent non‐cardiac surgical procedure listed in the Operative Stress Score categories. The exposure of the study was claims‐based frailty index (robust, < 0.15; pre‐frail, 0.15 to < 0.25; mildly frail, 0.25 to < 0.35; and moderate‐to‐severely frail, ≥ 0.35) with Operative Stress Score categories being 1, very low stress to 5, very high stress. The primary outcome was all‐cause mortality at 30 days and 365 days after the surgical procedure. Results In total, 1,019,938 patients (mean (SD) age of 76.1 (7.3) years; 52.3% female; 16.8% frail) were included. The cumulative incidence of mortality generally increased with Operative Stress Score category, ranging from 5.0% (Operative Stress Score 2) to 24.9% (Operative Stress Score 4) at 365 days. Within each category, increasing frailty was associated with mortality at 30 days (hazard ratio comparing moderate‐to‐severe frailty vs. robust ranged from 1.59–3.91) and at 365 days (hazard ratio 1.30–4.04). The variation in postoperative outcomes by patients' frailty level was much greater than the variation by the operative stress category. Conclusions These results emphasise routine frailty screening before major and minor non‐cardiac procedures and the need for greater clinician awareness of postoperative outcomes beyond 30 days in shared decision‐making with older adults with frailty.