TY - JOUR AB - In a group sequential clinical trial, accumulated data are analyzed at numerous time points to allow early decisions about a hypothesis of interest. These designs have historically been recommended for their ethical, administrative, and economic benefits. In this article, we first discuss a collection of new commands for computing the stopping boundaries and required group size of various classical group sequential designs, assuming a normally distributed outcome variable. Then, we demonstrate how the performance of several designs can be compared graphically. AU - Grayling, Michael J AU - Wason, James MS AU - Mander, Adrian P DA - 2018/06/01 DO - 10.1177/1536867X1801800208 EP - 431 IS - 2 J1 - Stata J JA - Stata J JF - The Stata Journal JO - The Stata Journal KW - st0529 KW - doubletriangular KW - haybittlepeto KW - innerwedge KW - powerfamily KW - triangular KW - wangtsiatis KW - clinical trial design KW - group sequential L2 - https://journals.sagepub.com/doi/abs/10.1177/1536867X1801800208 PB - SAGE Publications PY - 2018 SN - 1536-8734 SP - 416 T1 - Group sequential clinical trial designs for normally distributed outcome variables TI - Group sequential clinical trial designs for normally distributed outcome variables UR - https://doi.org/10.1177/1536867X1801800208 VL - 18 Y1 - 2018/06/01 ER -