Patient selection in the Comprehensive Care for Joint Replacement model.

Objective: To understand whether the Comprehensive Care for Joint Replacement (CJR) program induces participating hospitals to (1) preferentially select lower risk patients, (2) reduce 90-day episode-of-care costs, (3) improve quality of care, and (4) achieve greater cost reduction during its second year, when downside financial risk was applied.

Data Sources: We identified beneficiaries of age 65 years or older undergoing hip or knee joint replacement in the 100% sample of Medicare fee-for-service inpatient (Part A) claims from January 1, 2013 to August 31, 2017. Cases were linked to subsequent outpatient, Part B, home health agency, and skilled nursing facility claims, as well as publicly available participation status for CJR.

Study Design: We estimated the effect of CJR for hospitals in the 67 metropolitan statistical areas (MSA) selected to participate in CJR (785 hospitals), compared to those in 104 non-CJR MSAs (962 hospitals; maintaining fee-for-service). A difference-in-differences approach was used to detect patient selection, as well as to compare 90-day episode-of-care costs and quality of care between CJR and non-CJR hospitals over the first two performance years.

Data Collection: We excluded 172 hospitals from our analysis due to their preexisting BPCI participation. We focused on elective admissions in the main analysis.

Principal Findings: While reductions in 90-day episode-of-care costs were greater among CJR hospitals (-$902, 95% CI: -$1305, -$499), largely driven by a 16.8% (p < 0.01) decline in 90-day spending in skilled nursing facilities, CJR hospitals significantly reduced the 90-day readmission rate (-3.9%; p < 0.05) and preferentially avoided patients aged 85 years or older (-5.9%; p < 0.01) and Black (-7.0%; p < 0.01). Cost reduction was greater in 2017 than in 2016, corresponding to the start of downside risk.

Conclusions: Participation in CJR was associated with a modest cost reduction and a reduction in 90-day readmission rates; however, we also observed evidence of preferential avoidance of older patients perceived as being higher risk among CJR hospitals.