Abstract / Summary
Objective: To compare healthcare access among U.S. children with attention-deficit/hyperactivity disorder (ADHD) only, autism only, and co-occurring ADHD-autism, and to identify social inequities associated with unmet care using recent nationally representative data. Methods: We analyzed combined 2023-2024 National Survey of Childrens Health data for 13,576 children aged 3-17 years with current ADHD and/or autism. Six healthcare-access outcomes were examined: forgone healthcare, unmet mental health care, no medical home, coverage gap or inadequate insurance, unmet specialist care, and unmet care coordination. Survey-weighted modified Poisson regression estimated adjusted prevalence ratios (aPRs) and 95 percent confidence intervals (CIs). Six multiply imputed poverty measures were combined using Rubins rules. Sensitivity models additionally adjusted for functional difficulty. Results: Compared with ADHD only, co-occurring ADHD-autism was associated with higher prevalence of forgone healthcare (aPR, 1.73; 95 percent CI, 1.38-2.16), no medical home (1.11; 1.02-1.20), inadequate or discontinuous insurance (1.14; 1.03-1.28), unmet specialist care (1.49; 1.14-1.94), and unmet care coordination (1.15; 1.04-1.28). Autism only was associated with unmet mental health care (1.49; 1.13-1.97) and care coordination (1.13; 1.02-1.25). Food insufficiency, housing instability, and non-supportive neighborhood conditions were consistently associated with poorer access. After adjustment for functional difficulty, associations remained for co-occurring ADHD-autism with forgone and specialist care and for autism only with unmet mental health care. Conclusions: Healthcare access inequities differed by neurodevelopmental diagnostic group and social context. Pediatric systems should strengthen care coordination, specialty and mental health access, insurance continuity, family navigation, and responses to food and housing hardship. Keywords: attention-deficit/hyperactivity disorder; autism spectrum disorder; healthcare access; health disparities; social determinants of health