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Costs and staffing resource requirements for adaptive clinical trials: quantitative and qualitative results from the Costing Adaptive Trials project

Lookup NU author(s): Dr Nina WilsonORCiD, Rebecca Maier, Professor Helen Hancock, Professor James WasonORCiD



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


© 2021, The Author(s).Background: Adaptive designs offer great promise in improving the efficiency and patient-benefit of clinical trials. An important barrier to further increased use is a lack of understanding about which additional resources are required to conduct a high-quality adaptive clinical trial, compared to a traditional fixed design. The Costing Adaptive Trials (CAT) project investigated which additional resources may be required to support adaptive trials. Methods: We conducted a mock costing exercise amongst seven Clinical Trials Units (CTUs) in the UK. Five scenarios were developed, derived from funded clinical trials, where a non-adaptive version and an adaptive version were described. Each scenario represented a different type of adaptive design. CTU staff were asked to provide the costs and staff time they estimated would be needed to support the trial, categorised into specified areas (e.g. statistics, data management, trial management). This was calculated separately for the non-adaptive and adaptive version of the trial, allowing paired comparisons. Interviews with 10 CTU staff who had completed the costing exercise were conducted by qualitative researchers to explore reasons for similarities and differences. Results: Estimated resources associated with conducting an adaptive trial were always (moderately) higher than for the non-adaptive equivalent. The median increase was between 2 and 4% for all scenarios, except for sample size re-estimation which was 26.5% (as the adaptive design could lead to a lengthened study period). The highest increase was for statistical staff, with lower increases for data management and trial management staff. The percentage increase in resources varied across different CTUs. The interviews identified possible explanations for differences, including (1) experience in adaptive trials, (2) the complexity of the non-adaptive and adaptive design, and (3) the extent of non-trial specific core infrastructure funding the CTU had. Conclusions: This work sheds light on additional resources required to adequately support a high-quality adaptive trial. The percentage increase in costs for supporting an adaptive trial was generally modest and should not be a barrier to adaptive designs being cost-effective to use in practice. Informed by the results of this research, guidance for investigators and funders will be developed on appropriately resourcing adaptive trials.

Publication metadata

Author(s): Wilson N, Biggs K, Bowden S, Brown J, Dimairo M, Flight L, Hall J, Hockaday A, Jaki T, Lowe R, Murphy C, Pallmann P, Pilling MA, Snowdon C, Sydes MR, Villar SS, Weir CJ, Welburn J, Yap C, Maier R, Hancock H, Wason JMS

Publication type: Article

Publication status: Published

Journal: BMC Medicine

Year: 2021

Volume: 19

Issue: 1

Online publication date: 26/10/2021

Acceptance date: 13/09/2021

Date deposited: 09/11/2021

ISSN (electronic): 1741-7015

Publisher: BioMed Central Ltd


DOI: 10.1186/s12916-021-02124-z


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Funder referenceFunder name
National Institute for Health Research (NIHR130351 and TJ Senior Research Fellowship, NIHR-SRF-2015-08-001).
TJ also received funding from UK Medical Research Council (MC_UU_00002/14)