RATIONALE: In a recent I-year placebo-controlled equivalence study of the effects of fluticasone propionate aqueous nasal spray 200 mcg QD (FP) on prepubescent growth, two populations, the Intent-to-Treat (ITT) and the Primary, were defined a priori. Exploratory diagnostic methods suggested that definition of a third population was warranted. This Completer population included only subjects from the Primary population who had a full year's worth of valid height measurements.
METHODS: Subjects were 3-9 years old and showed clinical evidence of rhinitis and normal baseline growth and growth velocity. The Primary population excluded from the ITT subjects who violated enrollment criteria regarding normal growth or growth velocity, exhibited signs of sexual maturity during treatment, or had fewer than three monthly on-treatment height measurements. Growth velocity was estimated for each subject by regressing monthly mean height measurements on subject age. Equivalence between treatment groups was assessed via analysis of covariance, and by constructing a 95% confidence interval around the treatment difference in l-year growth velocity. Treatment differences in monthly height were assessed via analyses of covariance and via a repeated measures mixed models analysis.
RESULTS: In each population assessed, the treatment difference in growth velocity and its 95% confidence interval lay within the a priori equivalence bounds of _+0.8cm/year. Monthly height results were consistent among populations and analysis methods.
CONCLUSIONS: Regardless of the population defined, the statistical method used to analyze the data, or the growth measurement assessed, the study data indicated equivalence between FP and placebo in terms of growth after 1 year.
