Two definitions of executive-function improvement produced different response rates in analyses of SHP465 trials. A percentage cannot be interpreted accurately without identifying the rating scale and the rule used to classify a response.
Brown and colleagues analyzed two randomized, placebo-controlled adult ADHD trials of extended-release mixed amphetamine salts. One optimized doses and the other used fixed doses. The present publication reanalyzed existing trial data; it was not an additional independent dosing experiment.
Executive difficulties were measured using the Brown Attention-Deficit Disorder Scale. One response definition required an endpoint total below 50. Another classified improvement relative to the baseline score’s specified 90% confidence-interval range.
In the dose-optimization study, active-treatment response rates were 41.9% under the below-50 rule and 57.4% under the confidence-range rule. Corresponding placebo rates were 19.2% and 29.6%. Both definitions favored active treatment in nominal statistical comparisons.
The distinction reflects different classification questions. Crossing an absolute scale threshold and moving beyond a baseline-derived range are not equivalent events. Neither percentage should be substituted for a response rate defined using an ADHD symptom scale or a cognitive performance test.
These were post hoc rating-based analyses, with nominal p values. Threshold choice, baseline severity, missing data and the selected trial population affect interpretation. The trials were industry sponsored, and their results require prospective confirmation for any new decision rule.
A favorable rating classification does not establish normalized functioning in every setting, permanent remission or driving safety. The evidence supports a treatment-related difference under explicit definitions, while keeping the measured construct and its limits visible.
See the design of a separate forced-dose SHP465 study.
Improved Executive Function in Adults Diagnosed With Attention-Deficit/Hyperactivity Disorder as Measured by the Brown Attention-Deficit Disorder Scale Following Treatment With SHP465 Mixed Amphetamine Salts Extended-Release: Post Hoc Analyses From 2 Randomized, Placebo-Controlled Studies. doi:10.1177/1087054720961819.