From Trials journal, 13 November 2013 (Full text available).
A randomised trial of adaptive pacing therapy, cognitive behaviour therapy, graded exercise, and specialist medical care for chronic fatigue syndrome (PACE): statistical analysis plan
Rebecca Walwyn(1,8,*), Email: R.E.A.Walwyn@leeds.ac.uk; Laura Potts(1), Paul McCrone(2), Anthony L Johnson(3,4), Julia C DeCesare(7), Hannah Baber(7), Kimberley Goldsmith(1), Michael Sharpe(5), Trudie Chalder(6), Peter D White(7).
1) MH&N Clinical Trials Unit, Institute of Psychiatry, King’s College London, DeCrespigny Park, London SE5 8AF, UK
2) Centre for the Economics of Mental Health, Institute of Psychiatry, King’s College London, DeCrespigny Park, London SE5 8AF, UK
3) MRC Biostatistics Unit, Institute of Public Health, University Forvie Site, Robinson Way, Cambridge CB2 0SR, UK
4) MRC Clinical Trials Unit, Aviation House, 125 Kingsway, London WC2B 6NH, UK
5) University Department of Psychiatry, Warneford Hospital, Oxford OX3 7JX, UK
6) Department of Psychological Medicine and Psychiatry, King’s College London, Weston Education Centre, Cutcombe Road, London SE5 9RJ, UK
7) Centre for Psychiatry, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1A 7BE, UK
8) Clinical Trials Research Unit, Leeds Institute of Clinical Trials Research, University of Leeds, Leeds LS2 9JT, UK
*) Corresponding author. Clinical Trials Research Unit, Leeds Institute of Clinical Trials Research, University of Leeds, Leeds LS2 9JT, UK
The publication of protocols by medical journals is increasingly becoming an accepted means for promoting good quality research and maximising transparency. Recently, Finfer and Bellomo have suggested the publication of statistical analysis plans (SAPs).
The aim of this paper is to make public and to report in detail the planned analyses that were approved by the Trial Steering Committee in May 2010 for the principal papers of the PACE (Pacing, graded Activity, and Cognitive behaviour therapy: a randomised Evaluation) trial, a treatment trial for chronic fatigue syndrome. It illustrates planned analyses of a complex intervention trial that
allows for the impact of clustering by care providers, where multiple care-providers are present for each patient in some but not all arms of the trial.
The trial design, objectives and data collection are reported. Considerations relating to blinding, samples, adherence to the protocol, stratification, centre and other clustering effects, missing data, multiplicity and compliance are described. Descriptive, interim and final analyses of the primary and secondary outcomes are then outlined.
This SAP maximises transparency, providing a record of all planned analyses, and it may be a resource for those who are developing SAPs, acting as an illustrative example for teaching and methodological research. It is not the sum of the statistical analysis sections of the principal papers, being completed well before individual papers were drafted.