An exploratory classroom analysis found differences in impairment levels between age and sex groups, but no consistent pattern showing that one sex benefited more from lisdexamfetamine. Baseline group differences and treatment interactions answer different questions.
The report examined a study in which 117 children aged 6–12 were randomized after open-label dose optimization. It reused the laboratory-school trial data, rather than adding an independent experiment. Analyses compared boys and girls and children aged 6–9 versus 10–12.
Classroom behavior and math-task measures were assessed repeatedly across the day. The post hoc analyses did not correct subgroup and time-point comparisons for multiple testing.
Girls generally showed less impairment than boys on several measures during both active treatment and placebo. Older children also showed lower impairment on selected classroom ratings. Such differences can occur without a difference in the active-minus-placebo treatment effect.
Some treatment-by-sex interactions appeared at individual time points, but they did not form a consistent pattern across scales and times. Isolated findings among many comparisons should not be converted into a robust sex-specific efficacy rule.
The sample included roughly three boys for every girl. The study was not prospectively powered for these subgroup comparisons, and smaller groups give less precise estimates. Adverse-event differences likewise require caution.
The industry-funded report supports further investigation of heterogeneity while showing why an overall benefit can coexist with uncertainty about moderators. It cannot identify an individual’s optimal dose, prove biological explanations for demographic differences or establish impairment from a group label.
See a different pediatric cognitive trial and its timing limitations.
Efficacy and tolerability of lisdexamfetamine dimesylate in children with attention-deficit/hyperactivity disorder: sex and age effects and effect size across the day. doi:10.1186/1753-2000-4-32.