Understanding Our Data & Methods: A Deep Dive into Medicaid and Intellectual/Developmental Disabilities (I/DD)
We strive for openness in our research. This page details the methodologies used to analyze Medicaid claims data and understand the experiences of individuals with Intellectual and Developmental Disabilities (I/DD). We wont you to have confidence in the insights we present.
Identifying Individuals with I/DD
Accurately identifying individuals with I/DD within large datasets like Medicaid claims requires a standardized approach. Here’s how we do it:
* Diagnosis Codes: We utilized a complete list of ICD-9 and ICD-10 diagnosis codes developed by the Assistant Secretary for Planning and Evaluation (ASPE).
* Categorization: These codes are grouped into six key categories:
* Intellectual Disabilities
* Developmental Delays/Disabilities
* Learning Disabilities
* Autism Spectrum Disorders
* Cerebral Palsy
* Spina bifida
* ASPE Methodology: You can explore the full ASPE methodology in their detailed report. A complete list of the specific diagnosis codes used in our analysis is available upon request.
who is Included in Our Analysis?
to ensure accuracy, we’ve established specific criteria for including enrollees in our calculations:
* Age Exclusion: We exclude individuals aged 65 and older.
* Medicare Exclusion: We also exclude those with at least one month of Medicare coverage.
* Rationale: These exclusions are crucial. Older adults and those with medicare may not have sufficient claims data in the T-MSIS system to reliably identify chronic conditions like I/DD.
Defining Long-Term Care Usage
Understanding long-term care needs is vital.Here’s how we categorized Medicaid long-term care utilization (as depicted in Figure 3 of our reports):
* Type of Service: We used the “type-of-service” code from the initial claim line, applying it to the header claim within a merged dataset.
* Included Services: We included anyone with at least one month of Medicaid enrollment utilizing:
* Institutional Care (nursing facilities, intermediate care facilities)
* Home Care (home health, personal care, 1915(c) waivers, 1115 waivers, and other home care services)
* Combined Categories: individuals using both institutional and home care were categorized under “institutional care” to avoid double-counting.
* Further Information: for a more detailed explanation, please refer to KFF’s brief on Medicaid long-term services and supports.
Identifying Chronic Conditions
Beyond I/DD, we also analyzed the prevalence of other chronic conditions.Here’s our approach (as shown in Figure 5):
* CCW Algorithm: We leveraged the 2020-updated CCW algorithm to identify chronic conditions.
* Mental Illness & Substance Use Disorder: We supplemented the CCW algorithm with data from seperate sources for mental illness and substance use disorder. You can find more information here:
* Medicaid Coverage for Adults with Mental Illness (KFF)
* Substance Use Disorder Treatment in Medicaid (KFF)
* Additional Conditions: We also included obesity, HIV, and hepatitis C in our definition of chronic conditions: Related reading
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