doi: 10.1111/j.1472-8206.2007.00513.x ORIGINAL ARTICLE Evaluation of two evidence-based knowledge transfer interventions for physicians. A cluster randomized controlled factorial design trial: the CardioDAS Study Emmanuel Amsallem, Christelle Kasparian, Michel Cucherat, Sylvie Chabaud, Margaret Haugh, Jean-Pierre Boissel, Patrice Nony* Service de Pharmacologie Clinique – UMR CNRS 5558, Ho ˆpital Cardiologique, 69003 Lyon, France INTRODUCTION In essence, evidence-based medicine (EBM) is rooted in five linked ideas: first, clinical decisions should be based on the best available scientific evidence; secondly, the clinical problem–rather than habits or protocols–should determine the type of evidence to be sought; thirdly, identifying the best evidence means using epidemiolog- ical and biostatistical ways of thinking; fourthly, conclusions derived from identifying and critically Keywords educational outreach, evidence-based medicine, knowledge transfer, professional practice, randomized controlled trial Received 12 December 2006; revised 20 February 2007; accepted 15 May 2007 *Correspondence and reprints: pn@upcl.univ-lyon1.fr ABSTRACT To investigate the potential benefits of two modes of evidence-based knowledge transfer (‘active’ and ‘passive’ modes) in terms of improvement of intention of prescription, knowledge, and real prescription in practice, we performed an open randomized controlled trial (CardioDAS) using a factorial design (two tested interventions: ‘active’ and ‘passive’ knowledge transfer) and a hierarchical structure (cluster of physicians for each department level). The participants were cardiologists working in French public hospitals. In the ‘passive’ transfer group, cardiologists received evidence-based knowledge material (available on Internet) every week for a duration of 1 year. In the ‘active’ transfer group, two knowledge brokers (EA, PN) visited the participating departments (every 2 months for 1 year, 2 h per visit). The primary outcome consisted in the adjusted absolute mean variation of score (difference between post- and pre-study session) of answers to simulated cases assessing the intention to prescribe. Secondary outcomes were the variation of answers to a multiple-choice questionnaire (MCQ) assessing knowledge and of the conformity of real prescriptions to evidence-based reference assessing the behavioral change. Twenty-two French units (departments) of cardiology were randomized (72 participating cardiologists). In the ‘active’ transfer group, the primary outcome was more improved than that in the control (P ¼ 0.031 at the department level, absolute mean improvement of 5 points/100). The change in knowledge transfer (MCQ) was also significant (P ¼ 0.039 at the department level, absolute mean improvement of 6 points/100). However, no benefit was shown in terms of prescription conformity to evidence. For the ‘passive’ mode of knowledge transfer and for the three outcomes considered, no improvement was identified. CardioDAS findings confirm that ‘active’ knowledge transfer has some impact on participants’ intent to prescribe and knowledge, but no effect on behavioral outcome. ‘Passive’ transfer seems far less efficient. In addition, the size of the benefit remains small and its consequences limited in practice. Journal compilation ª 2007 Blackwell Publishing Ltd. No claim to original French government works Fundamental & Clinical Pharmacology 21 (2007) 631–641 631