It has recently come to our attention that some of the results presented in Table II in ’A conditional error function approach for subgroup selection in adaptive clinical trials’ (Statistics in Medicine 2012; 31:4309–4320) are not correct. An R software coding issue resulted in numerical errors in the reported results for the conditional error function approach (CEF) and for the combination test approach by Spiessens and Debois (CT-SD). We have corrected these errors in the following table. We also, for reasons of consistency with the CEF approach, now present type I error rates for the CT-SD approach based purely on rejection of the intersection hypothesis rather than as previously on rejection of both intersection and one or the other of the elementary hypotheses and . It is now clear that type I error rates are controlled at the nominal 2.5% level for both approaches, and our previous assertion that the CEF methodology was uniformly, although only marginally, more powerful than the CT-SD methodology is no longer supported by the simulation results for the selected scenarios. Correction of coding errors produced such small changes to data presented in Figures 1–3 as to be indistinguishable from normal simulation error; updated data underlying these plots are available on request from the authors. We apologize for any inconvenience this error has caused.
|n1 ∕ (n1 + n2)||ε||τ||CEF||CT-SD|