Gillies, KateKearney, AnnaKeenan, CiaraTreweek, ShaunHudson, JemmaBrueton, ValerieConway, ThomasHunter, AndrewMurphy, LouiseCarr, Peter JRait, GretaManson, PaulAceves Martins, Magaly2022-03-062022-03-062021-03-06Gillies, K, Kearney, A, Keenan, C, Treweek, S, Hudson, J, Brueton, V, Conway, T, Hunter, A, Murphy, L, Carr, P J, Rait, G, Manson, P & Aceves Martins, M 2021, 'Strategies to improve retention in randomised trials', Cochrane Database of Systematic Reviews, vol. 3, no. 3, MR000032. https://doi.org/10.1002/14651858.MR000032.pub31469-493XJisc: e989183d740a4840a136300776c3f0c6ORCID: /0000-0002-9441-142X/work/94083649ORCID: /0000-0001-7890-2854/work/94084091ORCID: /0000-0002-7239-7241/work/186968535https://hdl.handle.net/2164/18164Acknowledgements We thank Jayne Tierney, Sally Stenning, Seeromanie Harding, Sarah Meredith, and Irwin Nazareth for their contributions to earlier versions of this review. We also thank all authors of included published studies who provided additional or unreported data and Principal investigators for data on studies in progress or completed and unpublished. This update was funded by a National Institute for Health Research (NIHR) Incentive Award Scheme 2019 Reference 130660. The Health Services Research Unit, University of Aberdeen receives core funding from the Chief Scientist Office of the Scottish Government Health Directorates. The views expressed in this review are those of the authors and do not necessarily reflect those of the NIHR, the Department of Health and Social Care or these other funders. Sources of support Internal sources: No sources of support supplied External sources: National Institue for Health Research Incentive Award, UK; This update was funded by a National Institue for Health Research Incentive Award [NIHR IA 130660].1901659339engcase managementcorrespondence as topicPatient Compliancepatient dropoutsRandomized Controlled Trial as topicrewardsurveys and questionnairesR MedicinePharmacology (medical)National Institute for Health Research (NIHR)130660RJournal article10.1002/14651858.MR000032.pub3http://www.scopus.com/inward/record.url?scp=85102607252&partnerID=8YFLogxK33