Objective: The study aims to determine the demographic predictors of attention-deficit/hyperactivity disorder (ADHD) in hospitalized children with autism spectrum disorder (ASD) and the impact of comorbidities on the length of stay (LOS).
Methods: A retrospective study was performed using a nationwide inpatient sample (NIS) from the United States (US) hospitals. All patients were ≤18 years age with a primary diagnosis of ASD (n = 3,095) were grouped by co-diagnosis of ADHD. Logistic regression was used to calculate the odds ratio (OR) and linear regression model was used for estimation of LOS.
Results: Boys had two-folds higher odds of comorbid ADHD (OR: 2.2, 95%CI: 1.741-2.749, p: < 0.001) compared to girls. ADHD was prevalent in adolescents (58.7%) and Caucasians (66.7%). These children were mainly from the South (30.8%) and Midwest (29.9%) regions of the US. Psychosis was seen in 37.3% of patients with ADHD and these patients had higher likelihood for comorbid psychosis (OR: 1.8, 95%CI: 1.485-2.090) compared to non-ADHD cohort. Children in the ADHD cohort stayed longer in the hospital (9.2 days) compared to the non-ADHD (7.9 days). Comorbid depression and ADHD increased the LOS in hospitals for ASD by 2.1 days and 0.9 days, respectively.
Conclusion: Our study led us to determine the demographic predictors of comorbid ADHD in patients with autism, and we believe that our findings can help to better serve these patients and their families. Comorbid ADHD and depression can prolong the length of hospitalization and they necessitate the need for acute inpatient care in such patients.