Treatment Patterns among Children and Adolescents with Attention-Deficit/Hyperactivity Disorder with or without Psychiatric or Neurologic Comorbidities in Sweden: A Retrospective Cohort Study.

INTRODUCTION: Attention-deficit/hyperactivity disorder (ADHD) is a common psychiatric disorder in children/adolescents and occurs frequently with psychiatric/neurologic comorbidities. The objective of this study was to assess the impact of psychiatric/neurologic comorbidities on pharmacotherapy patterns among patients with ADHD in Sweden.

METHODS: A retrospective cohort analysis was conducted using medical records from a regional database in Sweden. Patients aged 6-17 years, with ≥1 prescription for ADHD medication between July 1, 2007 and June 30, 2009, and continuously active in the database for ≥12 months before and after their prescription index date were selected. Patients were categorized as ADHD alone (ADHD-only) or with comorbidities (ADHD-comorbid). Between-group differences were analyzed before and after adjusting for potentially confounding variables.

RESULTS: Data on 1794 patients (1083 ADHD-only; 711 ADHD-comorbid) were analyzed. Among newly treated patients, 21.7% augmented their index therapy (ADHD-only, 20.5%; ADHD-comorbid, 24.4%; p = 0.23). After adjustment, ADHD-only patients were less likely (p = 0.002) to augment versus ADHD-comorbid patients [odds ratio = 0.44, 95% confidence interval (CI) 0.27, 0.73]. ADHD-comorbid patients received more prescriptions versus ADHD-only patients (mean 13.1 vs 10.0; p < 0.001), and had more outpatient visits (mean 11.9 vs. 8.1; p < 0.001) and hospitalizations (10.7% vs. 6.0%; p < 0.001). After adjustment, ADHD-only patients had fewer outpatient visits (p < 0.001) and referrals (p < 0.001) versus ADHD-comorbid patients (visits: β = -0.21, 95% CI -0.28, -0.13; referrals: β = -0.25, 95% CI -0.33, -0.18).

CONCLUSION: Patients with ADHD with comorbidities had more hospitalizations, physician visits, and medication prescriptions during 12 months' follow-up than did those with ADHD alone. ADHD therapy augmentation was prevalent among children/adolescents with ADHD, even among those without psychiatric/neurologic comorbidities.