Author’s response to reviews
Title: Stepped wedge cluster randomised trials: a review of the statistical methodology used and
available
Authors:
Daniel Barker ([email protected])
Patrick McElduff ([email protected])
Catherine D'Este ([email protected])
Michael Campbell ([email protected])
Version: 1 Date: 11 Mar 2016
Author’s response to reviews:
Dear Editors,
Please accept a revised version of the manuscript “Stepped wedge cluster randomised trials: a
review of the statistical methodology used and available” for consideration for publication in
your journal. Neither this manuscript nor a version of it have been published or are currently
being considered for publication elsewhere.
The revision has placed more emphasis on the strengths of our review, not the least of which is
the inclusion of far more examples of stepped wedge trials in practice. We point out that the next
largest review had approximately one third of the number of trials that are in this manuscript
which has resulted in an overestimate of the number of clusters typically randomised in stepped
wedge trials. This is an important distinction because the options for statistical analysis are
heavily dependent on the number of clusters available. Another feature of our review which is
not found in the earlier reviews is the comparison between the types of stepped wedge trials and
the statistical methodology built up around them. We highlight that in the case of the cohort
stepped wedge design the theory lags behind the practice.
As part of this process we had regular discussions with Professor Michael Campbell who is an
expert in cluster randomised trials and therefore he has been added as an author.
Yours sincerely,
Mr Daniel Barker
School of Medicine and Public Health
University of Newcastle