Translating Attention-Deficit/Hyperactivity Disorder Rating Scale-5 and Weiss Functional Impairment Rating Scale-Parent Effectiveness Scores into Clinical Global Impressions Clinical Significance Levels in Four Randomized Clinical Trials of SPN-812 (Viloxazine Extended-Release) in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

Objectives: Clinical trials in psychiatry frequently report results from lengthy, comprehensive assessments to characterize a subject emotionally, cognitively, and behaviorally before and after treatment. However, the potential treatment implications of these results and how they translate into clinical practice remain unclear. Conversely, the Clinical Global Impressions (CGI) scales are quick, intuitive assessments used to assess the functional impact of a treatment in clinically relevant terms. The objectives of the present analyses are to translate scores from comprehensive assessments of symptom severity and functional impairment into clinically meaningful CGI levels. Methods: These post-hoc analyses use data integrated from four pivotal Phase 3 trials in attention-deficit/hyperactivity disorder (ADHD) in children and adolescents treated with the novel nonstimulant SPN-812 (Viloxazine Extended-Release). In this study, we evaluated the ADHD Rating Scale-5 (ADHD-RS-5) and Weiss Functional Impairment Rating Scale-Parent (WFIRS-P), assessments of symptom severity and functional impairment, respectively, by linking these scales with the CGI scales at baseline and end of study. Results: For participants that improved, a one-level change on the CGI-Improvement (CGI-I) was associated with a 10-15-point change on the ADHD-RS-5, and a 0.2-0.5-point change on the WFIRS-P. On the CGI-I, ratings of much improved and very much improved were associated with a percent score decrease (i.e., improvement) of ∼55% and 80% on the ADHD-RS-5 and ∼40% and 70% on the WFIRS-P, respectively. Differences between children and adolescents were minor and are unlikely to be clinically meaningful. Conclusion: These post-hoc analyses provide clinically meaningful benchmarks for the interpretation of scores on the ADHD-RS-5 and WFIRS-P in terms of CGI evaluations in subjects with ADHD. These results may be useful for physicians seeking to understand a treatment's potential impact on their ADHD patients or for researchers looking to define their study results within a clinically relevant context. Data are from clinical trials NCT03247530, NCT03247543, NCT03247517, and NCT03247556.