A Meta-analysis of the Consistency of Atomoxetine Treatment Effects in Pediatric Patients with Attention-Deficit/Hyperactivity Disorder from 15 Clinical Trials Across Four Geographic Regions

Abstract Objective: Atomoxetine has been approved as a treatment for children and adolescents with attention-deficit/hyperactivity disorder (ADHD) in the United States, throughout Europe, and in other countries. This meta-analysis was to assess the consistency of the treatment effect of atomoxetine across four global geographic regions. Methods: Data from 15 acute, double-blind, placebo-controlled trials were pooled (2 in Asia, 4 in Europe, 8 in North America, and 1 in Russia), yielding 2569 pediatric patients with ADHD. Improvements during 6–10 weeks of atomoxetine treatment were evaluated using the ADHD Rating Scale-IV or the Swanson, Nolan, and Pelham Scale–Revised. Consistency across regions was assessed by an interaction test and Higgins I2. Consistency of one region versus other regions was assessed by effect sizes of individual regions and pairwise differences. Results: Patient demographics were generally similar across regions. More patients from Asia met diagnostic criteria for ADHD inattentive s...