mmpc - National Indian Health Board

Methods
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n this section we describe technical issues regarding the Medicaid and IHS linked data and its
analysis in this report. The term ‘Medicaid data’ in this report includes both Medicaid and CHIP
data in state Medicaid programs (M-CHIP), but not CHIP data for state-only CHIP programs.
Medicaid and M-CHIP data are combined because, 1) there are small numbers of AIAN found to
have CHIP coverage in the IHS Areas in our past studies (American Indian and Alaska Native Medicaid
Program and Policy Data, 2010); 2) there is no State-only CHIP program data uniformly collected by
Medicaid; and 3) Medicaid expansion CHIP program data is required of Medicaid state programs and
is included in Medicaid data. Those readers interested in separate Medicaid and M-CHIP data
specific to each IHS Area for 2006 presented in exactly the same format as we did for 2004 data in
2010, please see the separate companion document we prepared with the enriched (linked) data
used in this report: AIAN Medicaid Data Linked to Indian Health Service Data: Medicaid and CHIP
Enrollment, Service Use and Payments, 2011.
Data Sources
Medicaid-IHS Linked Person Summary File
In 2011 we linked the CMS federal Medicaid/CHIP (MAX) Person Summary File for Calendar Year
(CY) 2006 to IHS registration data from the IHS National Data Warehouse (NDW). The methods and
linkage, and the resultant contents of the data file created are described in Integrating Medicaid and
Indian Health Service Data, 2011. The MAX Person Summary Files included in the linkage were state
files for the 35 states with IHS Contract Health Service Delivery Area (CHSDA) counties.
Medicaid Inpatient, Prescription Drug and Other Services Claims Files
The CMS-IHS linked Person Summary File made in 2011 was merged with MAX Inpatient,
Prescription Drug and Other Services claims files for Calendar Year (CY) 2006 by MAX identification
numbers. Claims paid for services in Fee-for-Service (FFS) delivery of care systems, and for
premiums paid in capitated (CAP) systems were provided for services that occurred in CY2006.
Payments processed through May 2007 were included in the MAX claims files, however. In this way
adjustments for adjudicated claims or payments among multiple payers are likely to have been
resolved so that payments represent amounts as close to ‘final’ as possible. In addition diagnostic
information was provided with paid claims in FFS delivery of care systems, and with encounter
records in CAP managed care plan systems.
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