Interpreting ADHD rating scale scores: Linking ADHD rating scale scores and CGI levels in two randomized controlled trials of lisdexamfetamine dimesylate in ADHD

David Goodman, Stephen V. Faraone, Lenard A. Adler, Bryan Dirks, Mohamed Hamdani, Richard Weisler

Research output: Contribution to journalArticle

Abstract

Objective: To provide additional understanding of the clinical significance of Attention-Deficit/Hyperactivity Disorder Rating Scale, Version IV (ADHD-RS-IV) total and change scores in relation to Clinical Global Impressions-Severity or -Improvement (CGI-S/-I) levels. Methods: Using two similarly designed pivotal trials of lisdexamfetamine dimesylate (Vyvanse, Shire US Inc), equipercentile linking was used to identify scores on the ADHD-RS-IV and CGI that have the same percentile rank. Results: As assessed by CGI-S levels, moderately, markedly, severely, and extremely ill adults had mean (SD) baseline ADHD-RS-IV scores of 36.2 (4.9), 42.1 (6.1), 45.4 (5.1), and 53.0, respectively. A similar relationship was observed in children. At endpoint, children categorized as minimally, much, or very much improved by CGI-I demonstrated mean (SD) ADHD-RS-IV changes from baseline of -9.9 (6.8), -25.5 (7.2), and -33.2 (9.3), respectively. Adults demonstrated a similar relationship between ADHD-RS-IV change scores and CGI-I ratings. Based on equipercentile link function, a change from baseline in ADHD-RS-IV total score of ∼10-15 points or 25% to 30% corresponded to a change of 1 level in CGI-I score. Conclusion: This analysis makes possible the establishment of a clinical impression of severity of illness from total ADHD-RS-IV scores and may facilitate the clinical interpretation of improvement of ADHD-RS-IV change scores.

Original languageEnglish (US)
Pages (from-to)44-52
Number of pages9
JournalPrimary Psychiatry
Volume17
Issue number3
StatePublished - Mar 1 2010

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ASJC Scopus subject areas

  • Psychiatry and Mental health

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