Testing the Feasibility of a Cross-Setting Measure to Address the Rising Trend in Hospital Outpatient TJA Procedures.

Background: Elective primary total hip and total knee arthroplasty (collectively, total joint arthroplasties [TJAs]) are commonly performed procedures that can reduce pain and improve function. TJAs are generally safe, but complications can occur. Although historically performed as inpatient procedures, TJAs are increasingly being performed in the outpatient setting. We sought to develop a scientifically acceptable cross-setting measure for evaluating care quality across inpatient and outpatient settings.

Methods: Using Medicare administrative claims and enrollment data for qualifying TJA patients, we respecified the Centers for Medicare & Medicaid Services (CMS) inpatient-only risk-standardized TJA complications measure to assess complication rates following elective primary TJAs performed in an inpatient or outpatient setting. We aligned inpatient and outpatient coding practices and used hierarchical logistic regression to calculate hospital-specific, risk-standardized complication rates (RSCRs). Lower rates correspond to better quality. Using accepted approaches for CMS measures, we tested measure reliability and vetted key measure decisions with patient and provider input.

Results: A single combined model including the procedure setting as a risk variable produced the highest discrimination (C-statistic for a single combined model with a setting indicator: 0.664, C-statistic for the inpatient-only model: 0.651, C-statistic for the outpatient-only model: 0.638). Among the 2,747 hospitals with at least 25 TJAs, the mean RSCR (using the combined model with a setting indicator) was 2.91% (median RSCR: 2.85%; interquartile range: 2.59% to 3.18%). The median odds ratio for complication occurrence at a higher-risk hospital compared with a lower-risk hospital was 1.33.

Conclusions: We respecified a measure to assess hospital inpatient or outpatient TJA performance and evaluated the reliability and validity of the measure. The findings showed variation in hospital-level complication rates across settings as indicated by this measure, supporting the feasibility of evaluating hospital performance using a more representative population than inpatient TJAs alone.

Level of evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.