There is presumed to be significant overlap in the characteristics of patients treated across the three post-acute care settings, as well as overlap in the types and intensity of services provided. In its June 1996 report to Congress, ProPAC reported that distinctions among the services provided in post-acute care settings and the patients served by these providers had blurred.10 ProPAC attributed the increasing similarity in post-acute care services to Medicare payment and coverage policies and changes in technology. As previously mentioned, up until the late 1990s, Medicare paid for post-acute care services using cost-based reimbursement methodologies. Coupled with emerging technologies, such payment policies allowed new services to be delivered in post-acute settings. For example, cost-based payment policies permitted payment of high cost intravenous therapy in the home by HHAs. Further, the essentially unlimited reimbursement for therapies and drugs in SNFs permitted these facilities to deliver a more intense level of care than historically was found in hospitals, including rehabilitation hospitals.
Whether or not there was or continues to be similarities in patients and services across post-acute settings requires further study. Analyses of the characteristics of patients treated across post-acute care settings have typically compared post-acute care use and length of stay by preceding hospital DRG and length of stay. In its 1996 report, ProPAC found that there was significant overlap in the hospital-assigned DRG across [post-acute care] settings.11 However, in this same report, ProPAC concluded that more information is needed that would allow meaningful comparisons of the diagnoses, severity, and functional limitations of beneficiaries in all of these settings.12 At its December 2000 meeting, MedPAC (the Medicare Payment Advisory Commission which replaced ProPAC) members questioned what is actually known about the overlap in patients and services across post-acute care.13 Commission members raised questions about the comparability across post-acute care settings of patients severity of illness (i.e., which is in part a function of the length of preceding hospital stay) and functional status, and questioned how other non-clinical factors such as facility ownership, family support, and patient preferences may affect post-acute care use. In addition, Commission members questioned the comparability of services across post-acute care settings. Specifically, they noted that while similar services may be provided across post-acute care settings, the mix and intensity of those services may differ. In an ASPE sponsored study, Liu et al. found that providers, consumer groups, and others reported that following implementation of the SNF PPS, the similarity (i.e., overlap) in patients treated in and services provided by SNFs and rehabilitation facilities had diminished.14
There is a need for further research that examines the differences and similarities between patients treated by post-acute care providers and the outcomes of this care under the new payment systems. Such information could be used to support the current payment methodologies across post-acute care settings or could provide the foundation for alternative payment approaches. In addition, such research could help provide information on what should be measured in the post-acute care arena to monitor and assure the quality of care.