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Process evaluations for cluster-randomised trials of complex interventions: a proposed framework for design and reporting.

Grant, Aileen; Treweek, Shaun; Dreischulte, Tobias; Foy, Robbie; Guthrie, Bruce


Shaun Treweek

Tobias Dreischulte

Robbie Foy

Bruce Guthrie


Background: Process evaluations are recommended to open the 'black box' of complex interventions evaluated in trials, but there is limited guidance to help researchers design process evaluations. Much current literature on process evaluations of complex interventions focuses on qualitative methods, with less attention paid to quantitative methods. This discrepancy led us to develop our own framework for designing process evaluations of cluster-randomised controlled trials. Methods: We reviewed recent theoretical and methodological literature and selected published process evaluations; these publications identified a need for structure to help design process evaluations. We drew upon this literature to develop a framework through iterative exchanges, and tested this against published evaluations. Results: The developed framework presents a range of candidate approaches to understanding trial delivery, intervention implementation and the responses of targeted participants. We believe this framework will be useful to others designing process evaluations of complex intervention trials. We also propose key information that process evaluations could report to facilitate their identification and enhance their usefulness. Conclusion: There is no single best way to design and carry out a process evaluation. Researchers will be faced with choices about what questions to focus on and which methods to use. The most appropriate design depends on the purpose of the process evaluation; the framework aims to help researchers make explicit their choices of research questions and methods. Trial registration: NCT01425502.


GRANT, A., TREWEEK, S., DREISCHULTE, T., FOY, R. and GUTHRIE, B. 2013. Process evaluations for cluster-randomised trials of complex interventions: a proposed framework for design and reporting. Trials [online], 14, article number 15. Available from:

Journal Article Type Article
Acceptance Date Jan 12, 2013
Online Publication Date Jan 12, 2013
Publication Date Dec 31, 2013
Deposit Date Jul 30, 2018
Publicly Available Date Jul 30, 2018
Journal Trials
Print ISSN 1745-6215
Electronic ISSN 1745-6215
Publisher Springer
Peer Reviewed Peer Reviewed
Volume 14
Article Number 15
Keywords Process evaluation; Complex intervention; Cluster randomised controlled trial; Qualitative; Quantitative; Reporting
Public URL


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