15 citations · 29 across the 6 of their papers we have counts for
6 papers
Factorial clinical trials in the presence and absence of plausible statistical interactions between treatment factors. A historical review of the methodological literature
Rebecca E. A. Walwyn, Pritaporn Kingkaew, Alan A. Montgomery +2
Factorial trials can be conducted when statistical interactions between two or more treatment factors are not anticipated, but also when they are. A k-in-1 factorial trial answers…
Orthogonal factorial designs for trials of therapist-delivered interventions: Randomising intervention-therapist combinations to patients
Rebecca EA Walwyn, Rosemary A Bailey, Arpan Singh +2
It is recognised that treatment-related clustering should be allowed for in the sample size and analyses of individually-randomised parallel-group trials that evaluate therapist-de…
Sample size calculations for multilevel factorial longitudinal cluster randomised trials
Rhys Bowden, Rebecca Walwyn, Jessica Kasza +4
Typically, trials investigate the impact of either an individual-level intervention on participant outcomes, or the impact of a cluster-level intervention on participant outcomes.…
Efficient and flexible simulation-based sample size determination for clinical trials with multiple design parameters
Duncan T. Wilson, Rebecca E. A. Walwyn, Richard Hooper +2
Simulation offers a simple and flexible way to estimate the power of a clinical trial when analytic formulae are not available. The computational burden of using simulation has, ho…
A hypothesis test of feasibility for external pilot trials assessing recruitment, follow-up and adherence rates
Duncan T. Wilson, Rebecca E. A. Walwyn, Julia Brown +1
The power of a large clinical trial can be adversely affected by low recruitment, follow-up and adherence rates. External pilot trials estimate these rates and use them, via pre-sp…
Bayesian design and analysis of external pilot trials for complex interventions
Duncan T. Wilson, James M. S. Wason, Julia Brown +2
External pilot trials of complex interventions are used to help determine if and how a confirmatory trial should be undertaken, providing estimates of parameters such as recruitmen…