Influence of the Maryland All-Payer Model on Primary Total Knee Arthroplasties

In 2014, Maryland received a waiver for the Global Budget Revenue (GBR) program. We evaluated GBR’s impact on patient and hospital trends for total knee arthroplasty (TKA) in Maryland compared with the U.S. Specifically, we examined (1) patient characteristics, (2) inpatient course, and (3) costs and charges associated with TKAs from 2014 through 2016. METHODS: A comparative analysis of TKA-treated patients in the Maryland State Inpatient Database (n = 36,985) versus those in the National Inpatient Sample (n = 2,117,191) was performed. Patient characteristics included race, Charlson Comorbidity Index (CCI), morbid obesity, patient income status, and primary payer. Inpatient course included length of hospital stay (LOS), discharge disposition, and complications. RESULTS: In the Maryland TKA cohort, the proportion of minorities increased from 2014 to 2016 while the proportion of whites decreased (p = 0.001). The proportion of patients with a CCI of ≥3 decreased (p = 0.014), that of low-income patients increased (p < 0.001), and that of patients covered by Medicare or Medicaid increased (p < 0.001). In the U.S. TKA cohort, the proportion of blacks increased (p < 0.001), that of patients with a CCI score of ≥3 decreased (p < 0.001), and the proportions of low-income patients (p < 0.001) and those covered by Medicare or Medicaid increased (p < 0.001). In both Maryland and the U.S., the LOS (p < 0.001) and complication rate (p < 0.001) decreased while home-routine discharges increased (p < 0.001). Costs and charges decreased in Maryland (p < 0.001 for both) whereas charges in the U.S. increased (p < 0.001) and costs decreased (p < 0.001). CONCLUSIONS: While the U.S. health reform and GBR achieved similar patient and hospital-specific outcomes and broader inclusion of minority patients, Maryland experienced decreased hospital charges while hospital charges increased in the U.S. LEVEL OF EVIDENCE: Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.