The Physical and Mental Health of Middle Aged and Older Adults on the Autism Spectrum and the Impact of Intellectual Disability

Background and Purpose: A nascent body of preliminary evidence suggests that individuals on the autism spectrum live shorter lives and have more physical and mental health problems compared to the general population. Since so little is known about the larger population of middle aged and older adults on the autism spectrum, it is imperative to leverage existing population-level data to characterize their physical and mental health in order to inform individual and systems-level prevention efforts that can help people on the autism spectrum live long, healthy, and self-determined lives in their communities. This study describes the physical and mental health of a unique sample of all middle aged and older Wisconsin Medicaid beneficiaries with an autism spectrum disorder diagnosis and tests differences between those with and without co-occurring intellectual disability.

 

Methods: Data were obtained directly from the Wisconsin Department of Health Services under a limited data use agreement. Participants were 143 middle aged and older adults on the autism spectrum with two lifetime Medicaid claims for an ICD-9 or ICD-10 code, respectively, corresponding to autism, Asperger’s disorder, or pervasive developmental disorder not otherwise specified on two different days. We examined service claims from all providers (inpatient, outpatient, long-term care, home health, and dental) for health conditions between 2012-2015. We categorized these conditions based on an established system for grouping ICD-9 codes (immune conditions, cancer, cardiovascular risk factors, cardiovascular disease, endocrine disorders, neurologic disorders, gastrointestinal disorders, sleep disorders, psychiatric conditions) while also presenting prevalent individual conditions. We calculated unadjusted and adjusted odds ratios (aOR; adjusting for sex, race, and age) using logistic regression comparing those with intellectual disability to those without.

 

Results: Many physical and mental health problems, including immune conditions (70.6%), cardiovascular disease (49.0%) and its risk factors (46.2%), sleep disorders (85.3%), gastrointestinal disorders (49.7%), neurologic conditions (55.9%), and psychiatric disorders (72.0%) were highly prevalent in our full sample. When comparing odds of the categorized conditions between those with and without ID, we saw increased but not statistically significant odds of neurologic disorders and gastrointestinal disorders and decreased but not statistically significant odds for immune conditions, cardiovascular disease and its risk factors, and psychiatric disorders in middle aged and older adults on the autism spectrum with co-occurring intellectual disability. Post-hoc analyses of neurological and psychiatric conditions identified significantly increased odds of epilepsy (aOR=2.20; 95% CI=1.0, 5.1) and significantly decreased odds of anxiety (aOR=0.48; 95% CI=0.2, 1.0) and depression (aOR=0.25; 95% CI=0.1, 0.6).

 

Conclusions and Implications: This is the first US study to use claims data to characterize the physical and mental health problems of middle aged and older adults on the autism spectrum with and without intellectual disability. Our findings suggest that people on the autism spectrum have a high prevalence of health problems in midlife and old age, regardless of intellectual disability status. While more research is needed to confirm these findings and understand mechanisms, our results underscore the importance of prevention for high prevalence of physical and mental health problems in autism at the individual and systems level.