de Bruin, MarijnBlack, NicolaJavornik, NezaViechtbauer, WolfgangEisma, Maarten C.Hartman-Boyce, JamieWilliams, A. JessWest, RobertMichie, SusanJohnston, Marie2020-02-182020-02-182021de Bruin, M, Black, N, Javornik, N, Viechtbauer, W, Eisma, M C, Hartman-Boyce, J, Williams, A J, West, R, Michie, S & Johnston, M 2021, 'Underreporting of the active content of behavioural interventions : a systematic review and meta-analysis of randomised trials of smoking cessation interventions', Health Psychology Review, vol. 15, no. 2, pp. 195-213 . https://doi.org/10.1080/17437199.2019.17090981743-7199ORCID: /0000-0003-0124-4827/work/175114108https://hdl.handle.net/2164/13707Acknowledgements We thank the authors of the included studies who responded to our requests for materials on the (intervention and) comparator group support. These materials were crucial to achieving our current aims. We also thank the members of our advisory board panels, who provided valuable input into the broader study design. Funding This work was funded by Cancer Research UK (grant number C50862/A18446). The systematic review protocol was previously peer-reviewed by Cancer Research UK as part of the funding process. The funders had no role in protocol design, decision to publish, or preparation of the manuscript.202747757engSDG 3 - Good Health and Well-beingbehaviour change techniquecontrol groupintervention grouprandomised controlled trialreportingSystematic reviewCONSENSUSCARETAXONOMYADHERENCE INTERVENTIONSREHABILITATIONTHERAPIESPEOPLER Medicine (General)Psychiatry and Mental healthClinical PsychologyCancer Research UKC50862/A18446R1Journal article10.1080/17437199.2019.1709098http://www.scopus.com/inward/record.url?scp=85077893646&partnerID=8YFLogxK152