Carbon cost of pragmatic randomised controlled trials: retrospective analysis of sample of trials

doi:10.1136/bmj.b4187

Published 30 October 2009, doi:10.1136/bmj.b4187
Cite this as: BMJ 2009;339:b4187

Research

Carbon cost of pragmatic randomised controlled trials: retrospective analysis of sample of trials

Katy Lyle, research fellow¹, Louise Dent, acting principal research fellow¹, Sally Bailey, senior programme manager¹, Lynn Kerridge, chief executive officer¹, Ian Roberts, professor of epidemiology and public health², Ruairidh Milne, director of strategy and development¹

¹ NIHR Evaluation, Trials and Studies Coordinating Centre, University of Southampton, Southampton SO16 7NS, ² London School of Hygiene and Tropical Medicine, London WC1E 7HT

Correspondence to: K Lyle k.lyle{at}southamtpon.ac.uk

Objective To calculate the global warming potential, in carbondioxide (CO₂) equivalent emissions, from a sample of pragmaticrandomised controlled trials.

Design Retrospective analysis.

Data source Internal data held by NIHR Evaluation, Trials andStudies Coordinating Centre.

Studies included All eligible pragmatic randomised controlledtrials funded by the NIHR Health Technology Assessment programmeduring 2002 and 2003.

Main outcome measure CO₂ equivalents for trial activities calculatedwith standard conversion factors.

Results 12 pragmatic randomised controlled trials involvingmore than 4800 participants and a wide range of technologieswere included. The average CO₂ emission generated by the trialswas 78.4 (range 42.1-112.7) tonnes. This is equivalent to thatproduced in one year by approximately nine people in the UnitedKingdom. Commuting to work by the trial team generated the mostemissions (average 21 (11.5-35.0) tonnes per trial), followedby study centres’ fuel use (18 (9.3-32.2) tonnes per trial),trial team related travel (15 (2.0-29.0) tonnes per trial),and participant related travel (13 (0-46.7) tonnes per trial).

Conclusions CO₂ emissions from pragmatic randomised controlledtrials are generated in areas where steps could be taken toreduce them. A large proportion of the CO₂ emissions come fromtravel related to various aspects of a trial. The results ofthis research are likely to underestimate the total CO₂ emissionsassociated with the trials studied, because of the sources ofinformation available. Further research is needed to explorethe additional CO₂ emissions generated by clinical trials, overand above those generated by routine care. The results fromthis project will feed into NIHR guidelines that will adviseresearchers on how to reduce CO₂ emissions.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: http://creativecommons.org/licenses/by-nc/2.0/ and http://creativecommons.org/licenses/by-nc/2.0/legalcode.

Add to CiteULike CiteULike Add to Complore Complore Add to Connotea Connotea Add to Del.icio.us Del.icio.us Add to Digg Digg Add to Reddit Reddit Add to StumbleUpon StumbleUpon Add to Technorati Technorati What's this?