Racial disparities in diagnosis of attention-deficit/hyperactivity disorder in a US national birth cohort

Importance: There are limited data on the racial disparities in the incidence of attention-deficit/hyperactivity disorder (ADHD) diagnosis in children at the national level.
Objective: To explore differences in rates of diagnosis of ADHD and use of treatment among children by race and ethnicity.
Design, Setting, and Participants: This retrospective cohort study assessed insurance claims data of children born in the US between January 1, 2006, and December 31, 2012, who had continuous insurance coverage for at least 4 years. The last date of follow-up included in the cohort was June 30, 2019. Race/ethnicity designations were based on self-report and included non-Hispanic White, Black, Hispanic, and Asian. Data were analyzed between October 2019 and December 2020.
Exposures: Race and ethnicity.
Main Outcomes and Measures: ADHD diagnosis as defined by International Classification of Diseases codes (ninth or tenth editions) and treatment within 1 year of diagnosis, including medication and behavior therapy as defined by billing codes. Data on ADHD diagnosis and treatment were adjusted for sex, region, and household income in a multivariate Cox regression model.
Results: Among 238 011 children in the cohort (116 093 [48.8%] girls; 15 183 [6.7%] Asian, 14 792 [6.2%] Black, 23 358 [9.8%] Hispanic, and 173 082 [72.7%] White children), 11 401 (4.8%) were diagnosed with ADHD. The cumulative incidence at age 12 was 13.12% (95% CI, 12.79%-13.46%). In multivariate Cox regression adjusting for sex, region, and household income, the hazard ratio for Asian children was 0.48 (95% CI, 0.43-0.53); Black children, 0.83 (95% CI, 0.77-0.90); and Hispanic children, 0.77 (95% CI, 0.72, 0.82) compared with White children. In the first year after diagnosis, 516 preschool children (19.4%) received behavioral therapy only, 860 (32.4%) had medications only, 505 (19.0%) had both, and 774 (29.2%) had no claims associated with either option. A higher percentage of school-aged children (2904 [65.6%]) were prescribed medications, and fewer had therapy only (639 [14.4%]) or no treatment at all (884 [20.0%]). Compared with other groups, White children were more likely to receive some kind of treatment. Asian children had the highest odds of receiving no treatment (odds ratio compared with White children, 0.54; 95% CI, 0.42-0.70).
Conclusions and Relevance: Racial and ethnic disparities in the diagnosis and treatment of ADHD are evident. Future study is needed to elucidate the mechanism behind these disparities, with special attention to Asian children. Clinicians should provide racially sensitive care in the evaluation and treatment of ADHD. (author abstract)