TRIAL FORGE: a systematic approach to making trials more efficient

TRIAL FORGE: a systematic approach to making trials more efficient

Randomised trials, especially when brought together in systematic reviews, are regarded as the gold standard for evaluating the effects of healthcare treatments with thousands of trials and hundreds of systematic reviews reported every year.  PubMed has indexed over 370,000 reports of randomised trials; the World Health Organisation’s International Clinical Trials Registry Platform contains over 250,000 trial records, of which 71,000 are listed as recruiting; and the Cochrane Central Register of Controlled Trials contains more than 800,000 records. Tens of billions of dollars of public and private money are invested globally in trials every year (US$25 billion in the US alone in 20103) and the average cost of recruiting a patient to a trial in the UK is estimated to be almost £8,500.     

Much of these resources is wasted, often because results are not published, or are poorly reported. However, resources are also wasted because the research asks the wrong questions or is badly designed.  Moreover, despite trials being a cornerstone of evidence-based healthcare, the methodology and infrastructure for conducting these complex studies is a largely evidence-free zone.

The Trial Forge initiative aims to make trials more efficient by looking for small gains across all trial processes, from research question through to reporting.  It will encourage everyone connected with trials to be more sceptical of what we do by asking for the evidence behind all of our trial decisions.  Where no evidence exists (as will often be the case), Trial Forge will provide a platform to highlight this gap and bring researchers and others (including funders) together so that they can fill the gap.  Insights from disciplines not normally associated with trials, such as business and organisational change management, will be part of this efficiency drive.

Trial Forge won the 2019 Cochrane-REWARD Prize for reducing research waste ( 

Trial Forge is led by Shaun Treweek at the University of Aberdeen. Further details on Trial Forge are available at



Ongoing - Data Collection



Dawson S, Banister K, Biggs K, Cotton S, Devane D, Gardner H, Gillies K, Gopalakrishnan G, Isaacs T, Khunti K, Nichol A, Parker A, AM Russell, Shepherd V, Shiely F, Shorter G, Starling B, Williams H, Willis A, Witham MD and Treweek S. Trial Forge Guidance 3: randomised trials and how to recruit and retain individuals from ethnic minority groups—practical guidance to support better practice. Trials 2022, 23: 672.

Gardner H, Elfeky A, Pickles D, Dawson A, Gillies K, Warwick V, Treweek S. A good use of time? Providing evidence for how effort is invested in primary and secondary outcome data collection in trials.  Trials (accepted). Pre-print at

Clark, L. et al. (2022) ‘The PROMoting the USE of SWATs (PROMETHEUS) programme: Lessons learnt and future developments for SWATs’, Research Methods in Medicine & Health Sciences.

Elfeky A, Treweek S, Hannes K, et al. Using qualitative methods in pilot and feasibility trials to inform recruitment and retention processes in full-scale randomised trials: a qualitative evidence synthesis. BMJ Open 2022;12:e055521.

Murphy, E., Shiely, F. & Treweek, S. How much is the lack of retention evidence costing trial teams in Ireland and the UK?. Trials 23, 396 (2022).

Pirosca, S., Shiely, F., Clarke, M. Treweek S. Tolerating bad health research: the continuing scandal. Trials 23, 458 (2022).

Treweek, S., Miyakoda, V., Burke, D. Shiely F. Getting it wrong most of the time? Comparing trialists’ choice of primary outcome with what patients and health professionals want. Trials 23, 537 (2022).


Coleman, E., Arundel, C., Clark, L., Doherty, L., Gillies, K., Hewitt, C. A., Innes, K., Parker, A., Torgerson, D., & Treweek, S. (2021). Bah humbug! Association between sending Christmas cards to trial participants and trial retention: randomised study within a trial conducted simultaneously across eight host trials. BMJ, 375, [e067742].

Treweek, S., Banister, K., Bower, P. et al. Developing the INCLUDE Ethnicity Framework—a tool to help trialists design trials that better reflect the communities they serve. Trials 22, 337 (2021).


Crowley, E., Treweek, S., Banister, K. et al. Using systematic data categorisation to quantify the types of data collected in clinical trials: the DataCat project. Trials 21, 535 (2020).

El feky, A., Gillies, K., Gardner, H. et al. Non-randomised evaluations of strategies to increase participant retention in randomised controlled trials: a systematic review. Syst Rev 9, 224 (2020).

Gardner HR, Albarquoni L, El Feky A et al. A systematic review of non-randomised evaluations of strategies to improve participant recruitment to randomised controlled trials [version 1; peer review: 2 approved, 2 approved with reservations, 1 not approved]. F1000Research 2020, 9:86 (

Pirosca S, Clarke M and Treweek S. Learning from Cochrane systematic reviews: what improvements do these suggest for the design of trials? [version 2; peer review: 2 approved]. F1000Research 2020, 9:178 (

Treweek, S., Bevan, S., Bower, P. et al. Trial Forge Guidance 2: how to decide if a further Study Within A Trial (SWAT) is needed. Trials 21, 33 (2020).


Bruhn, H., Treweek, S., Duncan, A. et al. Estimating Site Performance (ESP): can trial managers predict recruitment success at trial sites? An exploratory study. Trials 20, 192 (2019).

Brunsdon, D., Biesty, L., Brocklehurst, P. et al. What are the most important unanswered research questions in trial retention? A James Lind Alliance Priority Setting Partnership: the PRioRiTy II (Prioritising Retention in Randomised Trials) study. Trials 20, 593 (2019). 

Gardner HR, Treweek S, Gillies K (2019) Using evidence when planning for trial recruitment: An international perspective from time-poor trialists. PLoS ONE 14(12): e0226081.


Treweek, S., Bevan, S., Bower, P. et al. Trial Forge Guidance 1: what is a Study Within A Trial (SWAT)?. Trials 19, 139 (2018).

El Feky A, Gillies K, Gardner H, Fraser C, Treweek S. A protocol for a systematic review of non- randomised evaluations of strategies to increase participant retention to randomised controlled trials. Systematic Reviews; 2018 Feb 16;:1–7.

Healy, P., Galvin, S., Williamson, P.R. et al. Identifying trial recruitment uncertainties using a James Lind Alliance Priority Setting Partnership – the PRioRiTy (Prioritising Recruitment in Randomised Trials) study. Trials 19, 147 (2018). 


Gardner, H.R., Fraser, C., MacLennan, G. et al. A protocol for a systematic review of non-randomised evaluations of strategies to improve participant recruitment to randomised controlled trials. Syst Rev 5, 131 (2016).


Treweek, S., Altman, D.G., Bower, P. et al. Making randomised trials more efficient: report of the first meeting to discuss the Trial Forge platform. Trials 16, 261 (2015).