Grimshaw, Jeremy MPresseau, JustinTetroe, JacquelineEccles, Martin PFrancis, Jill JGodin, GastonGraham, Ian DHux, Janet EJohnston, MarieLégaré, FranceLemyre, LouiseRobinson, NicoleZwarenstein, Merrick2014-10-292014-10-292014-08-06Grimshaw, J M, Presseau, J, Tetroe, J, Eccles, M P, Francis, J J, Godin, G, Graham, I D, Hux, J E, Johnston, M, Légaré, F, Lemyre, L, Robinson, N & Zwarenstein, M 2014, 'Looking inside the black box : results of a theory-based process evaluation exploring the results of a randomized controlled trial of printed educational messages to increase primary care physicians' diabetic retinopathy referrals [Trial registration number ISRCTN72772651]', Implementation Science, vol. 9, 86. https://doi.org/10.1186/1748-5908-9-861748-5908ORCID: /0000-0003-0124-4827/work/175114020http://hdl.handle.net/2164/3776This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.296928engSDG 3 - Good Health and Well-beingprocess evaluationtheory of planned behaviorprinted educational materialhealthcare professional behaviorbehavior changeR MedicineRJournal article10.1186/1748-5908-9-869