Sample size requirements to estimate key design parameters from external pilot randomised controlled trials: a simulation study

The statistical interpretation of pilot trials: should significance thresholds be reconsidered?

(2014) Ellen C Lee et al.   BMC Medical Research Methodology

Blinded sample size re-estimation in superiority and noninferiority trials: bias versus variance in variance estimation

(2013) Tim Friede et al.   PHARMACEUTICAL STATISTICS

A reinvestigation of recruitment to randomised, controlled, multicenter trials: a review of trials funded by two UK funding agencies

(2013) Ben G O Sully et al.   Trials

Sample size determinations in original research protocols for randomised clinical trials submitted to UK research ethics committees: review

(2013) T. Clark et al.   BMJ-British Medical Journal

The size of a pilot study for a clinical trial should be calculated in relation to considerations of precision and efficiency

(2011) Julius Sim et al.   JOURNAL OF CLINICAL EPIDEMIOLOGY

A tutorial on pilot studies: the what, why and how

(2010) Lehana Thabane et al.   BMC Medical Research Methodology