Impact of Medicare's Nonpayment Program on Venous Thromboembolism Following Hip and Knee Replacements.

Objective: To determine whether Medicare's Nonpayment Program was associated with decline in venous thromboembolism (VTE) following hip and knee replacements; and whether the decline was greater among hospitals at risk of larger financial losses from the Program.

Data Sources: State Inpatient Database for New York (NY) from 2005 to 2013.

Study Design: The primary outcome was an occurrence of VTE. Medicare Utilization Ratio (MUR), which is the proportion of inpatient days in a hospital that is financed by Medicare, represented a hospital's financial sensitivity. We used hierarchical logistic regressions with difference-in-differences estimation to study the Program effects.

Principal Findings: A total of 98,729 hip replacement and 111,361 knee replacement stays were identified. For hip replacement, the Program was associated with significant reduction (Range: 44% to 53%) in VTE incidence among hospitals in MUR quartiles 2 to 4. For knee replacement, the Program was associated with significant reduction (47%) in VTE incidence only among quartile 2 hospitals.

Conclusion: Implementation of the Program was associated with a reduction in VTE, especially for hip replacements, in higher MUR hospitals. Payment reforms such as Medicare's Nonpayment Program that withhold payments for complications are effective and should be continued.