Package: bbssr 3.0.0

bbssr: Blinded Sample Size Re-Estimation for Binary Endpoints

Tools for blinded sample size re-estimation (BSSR) in two-arm clinical trials with binary endpoints, together with the exact power and sample size calculations that the re-estimation relies on, for two independent groups, for matched pairs and for stratified designs. For two independent groups seven statistical tests are implemented: Pearson chi-squared, Fisher exact, Fisher mid-p, Z-pooled exact unconditional, the exact unconditional test of Boschloo (1970) <doi:10.1111/j.1467-9574.1970.tb00104.x>, and the tests of non-inferiority and equivalence of Blackwelder (1982) <doi:10.1016/0197-2456(82)90024-1> and of Farrington and Manning (1990) <doi:10.1002/sim.4780091208>, with a margin on the scale of the risk difference or the risk ratio. Each test is available with a one-sided or a two-sided alternative, and the exact unconditional tests can be combined with the Berger-Boos procedure. For matched pairs the McNemar tests and the score test of Nam (1997) <doi:10.2307/2533508> are implemented, and for stratified designs the Cochran-Mantel-Haenszel test, Cochran's test with the sample size formulas of Woolson et al. (1986) <doi:10.2307/2530706> and Nam (1992) <doi:10.2307/2532298>, and the stratified exact conditional test of Jung (2014) <doi:10.1002/bimj.201300048>. The power, the distribution of the final sample size and the type I error rate of a re-estimation design are computed exactly, by simulation for three or more strata and as averages over simulated allocation sequences for random stratum and group sizes, the significance level can be adjusted so that the type I error rate is controlled, and the sample size can be re-estimated from the blinded data of a trial that is under way. Statistical methods based on Mehrotra et al. (2003) <doi:10.1111/1541-0420.00051>, Berger and Boos (1994) <doi:10.1080/01621459.1994.10476836>, Friede and Kieser (2004) <doi:10.1002/pst.140>, Friede et al. (2007) <doi:10.1002/bimj.200610373> and Kieser (2020) <doi:10.1007/978-3-030-49528-2_21>.

Authors:Gosuke Homma [aut, cre]