title: Statistical Properties of the Design for Simultaneous Global Drug Development Program.
abstract: Recently, a design was proposed for the Simultaneous Global Drug Development Program (SGDDP) to assess the impact of ethnic factors on the effect of a new treatment for a targeted ethnic (TE) population. It used weighted Z tests to combine the information collected from the TE and non-TE (NTE) subgroups in the SGDDP based on the fundamental assumption on their shared biological commonality. In this article, we mathematically formulated this assumption as the quantitative interaction between treatment effect and subgroup. We used it to more rigorously describe the hypotheses, and showed the unbiasedness of the weighted Z test. Moreover, to study the loss of efficiency from down weighting the NTE information in this SGDDP design, we compared the power of their test with that of the uniformly most powerful (UMP) test, which we showed was also a weighted Z test. We discussed that the choice of weight should balance the maximization of power when the assumption holds and the minimization of bias otherwise.
authors.affiliation: a Department of Statistics and Biostatistics , Rutgers University , New Brunswick , New Jersey , USA.
authors.forename: Kezhen
authors.initials: K
authors.lastname: Liu
authors.affiliation: b Biostatistics, Johnson & Johnson , Raritan, New Jersey , USA.
authors.forename: Zhilong
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: b Biostatistics, Johnson & Johnson , Raritan, New Jersey , USA.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.affiliation: c Office of Biostatistics , Center for Drug Evaluation, SFDA , Beijing , P.R. China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Huang
authors.affiliation: b Biostatistics, Johnson & Johnson , Raritan, New Jersey , USA.
authors.forename: Judith
authors.initials: J
authors.lastname: Wenrich
mesh_terms: D000465:Algorithms; D001699:Biometry; D003627:Data Interpretation, Statistical; D015195:Drug Design; D004347:Drug Interactions; D005006:Ethnicity / Q000706:statistics & numerical data*; D006801:Humans; D010601:Pharmacology, Clinical / Q000706:statistics & numerical data*; D012107:Research Design / Q000706:statistics & numerical data*; D018401:Sample Size
keywords: Power; Quantitative interaction assumption; SGDDP; Unbiased; Weighted Z test