Assessing the hospital volume-outcome relationship in total elbow arthroplasty

Abstract

Background: Total elbow arthroplasty (TEA) is an effective intervention for multiple elbow disorders including complex fracture in elderly patients, post-traumatic arthropathy, inflammatory arthropathy, and distal humeral nonunion. Given its known therapeutic value and low utilization rate, an investigation into the thresholds for TEA institutional volume-outcome relationships is warranted. The purpose of this study was to identify TEA volume thresholds that serve as predictors of institutional outcomes including complications, readmissions, revisions, cost of care, length of stay (LOS), and non-home discharge. We hypothesized that increased institutional volume would be associated with decreased 90-day adverse outcomes and resource utilization.

Methods: The Nationwide Readmission Database was queried from 2010 to 2017 to identify all cases of TEA. Hospital volume was calculated using a unique hospital identifier and divided into quartiles. Outcomes such as complications, readmissions, revisions, cost of care, LOS, and non-home discharge were then analyzed by quartile. The same outcomes were assessed via stratum-specific likelihood ratio (SSLR) analysis to define volume strata among institutions.

Results: SSLR analysis defined statistically significant hospital volume categories for each 90-day outcome. The volume category with the lowest complication rate was ≥21 TEAs per year (5.6%). The volume categories with the lowest readmission rates were 1-3 TEAs per year (4.7%) and ≥18 TEAs per year (9.2%). Revision rates were lowest in the volume categories of 1-5 TEAs per year (0.1%) and ≥18 TEAs per year (0.1%). Hospitals with ≥21 TEAs per year had the lowest cost of care and the highest rate of extended LOS (>2 days). SSLR analysis showed that non-home discharges decreased in a stepwise manner as volume increased. The lowest non-home discharge rate was associated with the volume category of ≥22 TEAs per year (20.3%).

Conclusion: This study defines TEA volume strata for institutional outcomes. The highest TEA volume strata were associated with the lowest rates of 90-day complications, revisions, and non-home discharges and the lowest cost of care. This trend is likely attributable to the benefits of high-volume institutional experience and standardized patient-care processes.

Keywords: Total; arthroplasty; complications; elbow; outcomes; volume.