Intended for healthcare professionals


Descriptions of non-pharmacological interventions in clinical trials

BMJ 2013; 347 doi: (Published 11 September 2013) Cite this as: BMJ 2013;347:f5212
  1. Andrew Cook, consultant in public health medicine1,
  2. Lisa Douet, senior research fellow2,
  3. Isabelle Boutron, professor of epidemiology3
  1. 1Wessex Institute, University of Southampton, Southampton SO16 7NS, UK
  2. 2National Institute for Health Research Evaluation, Trials and Studies Coordinating Centre (NETSCC), University of Southampton, UK
  3. 3INSERM, University Paris Descartes, Paris, France
  1. andrewc{at}

Reporting must improve

Clinical trials are the standard for establishing the relative effectiveness of two interventions.1 Although work is being done to maximise the reporting of trials, thus minimising publication bias,2 other sources of bias lurk within trial reports. In a linked article (doi:10.1136/bmj.f3755), Hoffmann and colleagues report on the description of non-pharmaceutical interventions in published trials and conclude that fewer than 40% were adequately described.3 Because more than 40% of published trials are non-pharmaceutical, this is an important group.4 Furthermore, the findings have improved little over time.5

These are crucial omissions. Without adequate description it is difficult—if not impossible—to repeat the trial, and, more importantly, clinicians do not know how to deliver the tested intervention to their patients. This can have serious consequences for patients’ safety and is part of the growing agenda to reduce waste in clinical research.6

For the results to be interpreted accurately, all arms of a trial must be adequately described. If active interventions are poorly described, descriptions of the control are likely to be even worse. Hoffmann concentrated on the intervention—the “new” procedure.3 Our experience is that the comparator is often …

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