In our analyses, we have identified three types of organizational relationships for health care providers:
- Freestanding providers
- Hospital-based (owned) subproviders
- Colocated providers (excluding subproviders)
Hospital-based subproviders were identified through the HCRIS data. These data contain the provider ID numbers of all HHA, SNF, and IRF subproviders and their respective hosts. These data provided an accurate measure of the post-acute providers that an acute hospital owns.
Colocated providers were identified using the addresses reported in the OSCAR data. RTI geocoded the addresses for all post-acute providers in the OSCAR data to identify the latitude and longitude of each provider. RTI used this geocoded data with GIS to identify colocated facilities. Colocated providers were defined as those within 250 yards of each other. Though collocated providers may not have a formal organizational relationship with each other, their proximity is likely indicative of an informal relationship. It is important to note that the accuracy of this colocation definition is directly related to the level of accuracy of the address reported in OSCAR. Provider chains may report their corporate address in the OSCAR file, rather than the address of a specific provider, which limits the reliability of this measure.
The three types of organizational relationships are mutually exclusive. For example, a hospital-based subprovider was classified as such, though it is also likely to be colocated (located within 250 yards) with the acute provider. Colocated providers were restricted to those providers that are colocated but not identified as a hospital-based subprovider. This relationship is particularly relevant to LTCHs as LTCHs cannot be subproviders of acute hospitals under current rules. However, a substantial number are colocated within a hospital although they must be certified (and meet the conditions of) independent hospitals. All other organizational relationships not otherwise defined as hospital-based subprovider or colocated were defined as freestanding.
One type of organizational relationship that we were unable to define using these data sources was satellite providers. A satellite provider is a provider that is owned by another organization but operates at a separate geographic location. Satellite providers do not have unique provider IDs which prevents them from being identified as separately located entities through OSCAR or HCRIS data. These providers have the same provider IDs as their parent organization in most instances. Providers are required to report satellite facilities to their fiscal intermediaries but this is not done consistently. Geographic information on these providers is, therefore, unavailable although many function similarly to a subproviders by making beds available to the host facility. Hence, while the host provider may have no measurable financial relationship with the satellite provider, it may have an incentive to discharge to the satellite facility to reduce the length of stay associated with its payment. The satellite PAC provider also gains because they have a close referral source to increase their admissions; however, this relationship is not visible without accurate location information on each set of beds.
Chain relationships are another problematic area for measuring formal ties. The OSCAR data contain a variable identifying chain membership for each organization. Affiliation with a chain may reduce provider costs by allowing shared services across the corporation. However, the chain variable in the OSCAR data is not reliable and leads to undercounting of organizational relationships that exist between post-acute providers. The Provider Enrollment Chain Ownership System (PECOS) data are a relatively new dataset that has the potential to capture the location of satellite and other interorganizational relationships; however, the level of completeness of the data at this time is not sufficient for the current study.
Using the available data on organizational relationships, we created a set of variables to identify the type of organizational relationships. These variables identified the presence or absence of any subprovider, or any colocated provider for acute providers in the sample. More specifically, additional variables were created to identify whether the acute hospital had any IRF, SNF, or HHA subproviders or any IRF, or SNF colocated provider. These variables were used in multivariate analysis to predict any PAC service use, first post-acute discharge setting, index acute admission length of stay, episode payments, and acute hospital readmission during the post-acute episode.