Estimation after blinded sample size reassessment
(English)In: Statistical Methods in Medical Research, ISSN 0962-2802, E-ISSN 1477-0334Article in journal (Refereed) Epub ahead of print
Blinded sample size reassessment is a popular means to control the power in clinical trials if no reliable information on nuisance parameters is available in the planning phase. We investigate how sample size reassessment based on blinded interim data affects the properties of point estimates and confidence intervals for parallel group superiority trials comparing the means of a normal endpoint. We evaluate the properties of two standard reassessment rules that are based on the sample size formula of the z-test, derive the worst case reassessment rule that maximizes the absolute mean bias and obtain an upper bound for the mean bias of the treatment effect estimate.
Adaptive design, interim analysis, internal pilot study, point estimate, sample size reassessment
Medical and Health Sciences Natural Sciences
Research subject Statistics
IdentifiersURN: urn:nbn:se:su:diva-134707DOI: 10.1177/0962280216670424OAI: oai:DiVA.org:su-134707DiVA: diva2:1037443