With the increase in prevalence of autism spectrum disorder (ASD) over recent years (1, 2), much attention has been paid to U.S. children and adolescents in need of services. However, half-a-million youth with ASD will age into adulthood over the next decade (3), and many more adults are already in need of long-term services and supports. Medicaid is the primary source of healthcare coverage for these individuals (4), but little is known about the composition of the adult population with ASD in Medicaid.
We use Medicaid Analytic eXtract (MAX) data containing (1) all individuals under age 65 with claim(s) of ASD (299.xx) and (2) a random sample of 3,358,220 Medicaid beneficiaries without ASD or intellectual disability (ID, 317.xx-319.xx), between 2008–2012. Figure 1 shows the administrative prevalence (henceforth, “prevalence”) of individuals in Medicaid ages 18–64, by age category. The numerator includes individuals with 12-month continuous enrollment and either one inpatient or two outpatient visits for which ASD was a diagnosis. The denominator is the sum of the numerator plus the total Medicaid population (without ASD) in that age group with 12-month continuous enrollment. We assume that the percent of Medicaid beneficiaries (without ASD) with 12-month continuous enrollment is the same in each year as in our simple random sample of 3.3 million Medicaid recipients (without ASD or ID), ranging from 55% (2008) to 60% (2012).
Figure 1.
Administrative Prevalence of Autism Spectrum Disorder in the Adult Medicaid Population with 12-Month Annual Enrollment, 2008–2012
During 2008–2012, the prevalence of ASD among adults ages 18–64 in Medicaid with 12-month continuous annual enrollment rose from 2.8 per 1,000 to 4.1 per 1,000 (Figure 1). However, the prevalence of ASD for young adults ages 18–24 with ASD rose from 6.4 per 1,000 to 9.9 per 1,000. For adults ages 25–40, the prevalence of ASD rose from 2.6 per 1,000 to 3.8 per 1,000, while for ages 41–64, increases were more modest (1.1 per 1,000 to 1.5 per 1,000). With 77 million individuals ever enrolled in the Medicaid program in 2012, our results imply 46 million Medicaid recipients with 12-month continuous enrollment, of whom 78,261 were receiving services for ASD.
The higher prevalence of ASD in younger adults compared to older adults suggests additional services and supports for adults with autism, such as those that increase community integration and shown to improve employment opportunities, may be needed in the future. These results underline the importance of identifying effective and efficient service delivery models within Medicaid to serve the growing number of adults with ASD.
Footnotes
The authors have no disclosures to report.
References
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