Looking upstream: factors shaping the demand for postacute joint replacement rehabilitation.

Since 1993, the numbers of hip and knee replacements in the United States have increased 2-fold to 3-fold while lengths of stay in acute care have decreased by about half, leading to a significant growth in the use of postacute rehabilitative care for patients with a joint replacement. To document these trends, this article uses secondary analysis of acute hospital discharge survey data and evaluates projections to 2030. This article uses a market approach to identify 3 sets of factors that influence the use of joint replacements: (1) increasing patient demand, (2) increasing supply of practitioners, and (3) the role of fiscal intermediaries. The article reviews underlying epidemiologic trends, growing numbers of orthopedic surgeons performing the procedure, technologic innovations, changing indications for the procedure, changing payer mix, and the effects of payer attempts to contain joint replacement costs. An unintended effect of Medicare payment policy has been to shift costs from acute care to downstream postacute care. Medicare and private health plan reimbursement policies need to take into account this broader perspective and not examine joint replacement care and payment in isolated care settings. Future research and health policy needs to consider the interdependent features of the health care system by linking changes in postacute care with upstream changes both in society at large and in the organization, delivery, and financing of acute care associated with joint replacement.