The Relationship Between Frailty and Clinical and Patient-Reported Outcomes After Hip or Knee Arthroplasty: A Retrospective Cohort Study

Introduction: Frailty is associated with increased risks related to surgery. There is emerging consensus that assessment of these risks should include frailty, yet little is known regarding the relationship between prospective frailty measurement and clinical and patient-reported outcomes. Methods: This retrospective cohort study included adults having hip or knee arthroplasty in one health system between April 2016 and April 2021 within a quality improvement initiative to identify frail adults and support preoperative optimization of care and outcomes. The Risk Analysis Index (RAI) was completed, and scores were available at the time of initial consultation. Scores ≤ 29 were considered robust, 30 to 36 normal, 37 to 44 frail, and ≥ 45 very frail. The Hip Disability and Osteoarthritis Outcome Score-Joint Replacement (HOOS-JR) or Knee Injury and Osteoarthritis Outcome Score-Joint Replacement (KOOS-JR) was administered for the affected joint at preoperative and postoperative clinic visits as well as the patient-acceptable symptom state (PASS) and global rating of change. Patients were included if they had diagnosis-related group (DRG) codes for primary (DRG 469, 470) or bilateral (DRG 461, 462) joint arthroplasty, a completed postoperative HOOS-JR or KOOS-JR, and a preoperative RAI score recorded no more than 270 days before the eligible arthroplasty procedure. Postoperative periods were defined as 0 to 3 months and > 3 months. Results: Among 3350 individuals, the mean age for those with hip and knee arthroplasty was 64 and 67 years, respectively. RAI score–based frailty level was not associated with postoperative HOOS-JR and KOOS-JR score change at 0 to 3 months or > 3 months, % reaching substantial clinical benefit, global rating of change, or PASS at either time point. Frailty as measured by RAI was associated with longer hospital length of stay and 30-day but not 7-day readmission. Conclusion: These results suggest that frail patients can and do achieve similar outcomes compared with their more robust counterparts.