The first Improvement science and research methods seminar in 2021, featured Dr Vanessa Botan who presented her ‘Reflections on stepped-wedge trials: rationale, design, and analysis‘. Vanessa is a postdoctoral research associate in medical statistics, working on two major NIHR funded studies and a number of other projects at CaHRU since she completed her PhD at the University of Sussex. In her PhD she used psychological, physiological, and neuroscientific methods to investigate the relationship between vicarious pain perception and bodily consciousness. Prior to this she worked as a research assistant in social and clinical psychology having gained an MSc in Cognitive Neuroscience, a BSc in Biomedical Sciences and is an associate fellow of the Higher Education Academy.
Vanessa described stepped wedge designs and their origins in the Gambia Hepatitis Intervention Study which investigated vaccination to prevent hepatitis in the 1980s. She went on to describe the advantages such as providing alternative to individual randomization, when not offering an intervention or randomisation may be logistically difficult or deemed unethical, allowing flexibility of cluster size, and taking into account differences between communities while measuring outcomes at individual level.
She also discussed problems of contamination and time bias and went on to discuss the ways of analysing data in such designs and how these related to interurrupted time series designs using the NIHR Applied Research Collaboration East Midlands funded, ‘Hypos can strike twice’ intervention study as an example. To view the presentation please click below.