Geographic patterns in the prevalence of multiple neurodevelopmental disorders among children and adolescents in the United States: a cross-sectional study

BACKGROUND: To investigate the geographic distribution of multiple neurodevelopmental disorders (NDDs) across different US states. METHODS: Using data from 2016 to 2023 National Survey of Children's Health, we estimated the prevalence and combinations of multiple NDDs (defined as having ≥2 NDDs) at the state level among 272 598 children and adolescents aged 3-17 years. We also reported state-level prevalence estimates and combinations stratified by sociodemographic characteristics. RESULTS: Participant numbers ranged from 4391 in the Nevada to 11 275 in California during 2016-2023. Over half were male (51.7%), with a mean age of 10.2 years (standard deviation: 4.5). The national multiple NDDs prevalence was 8.1% (95% Confidence Interval [CI]: 7.9%-8.3%), with Kentucky reporting the highest prevalence at 10.5% (95% CI: 9.3%-11.8%) across states. Stratified analyses by period, age groups, sex, ethnicity, country of birth, household income, insurance coverage, and family education levels consistently showed the highest prevalence in southern states such as Florida, Kentucky, Louisiana, Maine, New Hampshire, and Oklahoma. Across states, the most common multiple NDDs combination was attention-deficit/hyperactivity disorder concurrent with learning disabilities (18.2%). CONCLUSION: Disparities in multiple NDDs prevalence were observed across US states. These state-level estimates can help decision-makers target programs and allocate resources to address community needs.