Hospitals participating in the Bundled Payments for Care Improvement initiative and Comprehensive Care for Joint Replacement model vary with respect to a number of organizational characteristics, according to a study reported yesterday in Health Affairs. Although the two groups had similar baseline spending and quality for joint replacement care, hospitals participating in the voluntary BPCI model 2 had higher average patient volume and were larger and more teaching intensive than hospitals in the mandatory CJR model. “These findings could temper policy makers’ expectations that either voluntary or mandatory programs alone can achieve the desired broad impact,” the authors said. “Instead, our results suggest that both voluntary and mandatory approaches can play an important role in engaging hospitals across the country, and that perhaps policy makers should not restrict policy options to one approach over the other.” The authors also call for future research on how the differences in hospitals’ baseline characteristics affect their ability to ultimately succeed in joint replacement programs.