Impact of atypical antipsychotic use among adolescents with attention-deficit/hyperactivity disorder.

OBJECTIVES: To compare treatment patterns, resource utilization, and costs to US third-party payers of stimulant-treated adolescent attentiondeficit/ hyperactivity disorder (ADHD) patients who switched to or augmented with atypical antipsychotics (AAPs; not FDA-indicated for ADHD) with those who switched to or augmented with nonantipsychotic medications. STUDY DESIGN: Retrospective cohort study conducted using a US commercial medical/pharmacy claims database. METHODS: Adolescent patients with an ADHD diagnosis and ≥ 1 stimulant medication claim between January 2005 and December 2009 were identified. Patients were classified into the AAP or non-antipsychotic cohorts based on subsequent claims for AAPs or non-antipsychotic medications, respectively. Patients with psychiatric diagnoses for which AAPs are often prescribed were excluded. Patients were matched 1:1 from the AAP to the non-antipsychotic cohort using propensity score matching. Treatment patterns, resource utilization, and costs in the 12 months after AAP or non-antipsychotic initiation were compared using Cox models, Poisson regression, and Wilcoxon signed-rank tests, respectively. RESULTS: After propensity score matching, a total of 849 adolescents were included in each of the matched cohorts. Patients in the AAP cohort had a significantly higher rate of medication augmentation (27.7% vs 15.5%; hazard ratio = 2.56; 95% confidence interval [CI], 1.90-3.46; P < .001) than patients in the non-antipsychotic cohort. The AAP cohort also had significantly higher incidences of inpatient admissions (0.13 vs 0.05; incidence rate ratio [IRR] = 2.45; 95% CI, 1.73-3.48; P < .001), emergency department visits (0.39 vs 0.31; IRR = 1.27; 95% CI, 1.08-1.49; P = .004), and outpatient visits (14.82 vs 13.19; IRR = 1.12; 95% CI, 1.10-1.15; P < .001), and incurred significantly higher mean annual medical ($3622 vs $3311; P = .002), drug ($4314 vs $2884; P < .001), and total healthcare ($7936 vs $6195; P < .001) costs. CONCLUSIONS: Stimulant-treated adolescents with ADHD who switched to or augmented with AAPs had significantly greater drug augmentation, healthcare resource utilization, and costs compared with the non-antipsychotic cohort.