The field of hemophilia has advanced tremendously over the past few decades leading to significant improvements to a patient's life expectancy. However, gaps in clinician's knowledge about appropriate tailored management of hemophilia can result in suboptimal patient outcomes. A study was conducted to determine if a series of online educational interventions on hemophilia could improve the knowledge and confidence of hematologists/oncologists in treating patients with hemophilia.The Perelman School of Medicine at the University of Pennsylvania, Office of CME, the National Hemophilia Foundation and Medscape, LLC, in partnership with an expert steering committee, developed a global, accredited educational curriculum (http://www.medscape.org/sites/advances/hemophilia-management) focused on the advances in the management of hemophilia. Six activities, including text and video formats, within the curriculum were evaluated using a pre-assessment/post-assessment study design comparing participants' responses to knowledge and case-based multiple choice questions before exposure to educational content (pre-assessment measurement) with the same participants' responses after participation in the educational activity (post-assessment measurement). Outcomes assessment questions focused on current evidence-based recommendations for the management of hemophilia. For all questions combined, paired 2-tailed t-test was used to assess whether the mean pre-assessment score was different from the mean post-assessment score. The effect size (Cohen's d) was calculated by comparing pre-assessment means and post-assessment means of linked learners to show the effect of educational intervention. Effect size of >0.8 and 0.4-0.8 are considered a large and medium effect size, respectively.A total of 256 hematologist/oncologist participants who completed all pre- and post- assessment questions for each assessment were included in the evaluation across the 6 interventions. An increase in knowledge and performance was demonstrated as a result of participation in each of the 6 interventions with effect sizes of 0.25, 0.559, 0.618, 0.721, 1.26, and 2.275. Topics that demonstrated the largest statistically significant increases in correct post-assessment compared with pre-assessment answers included: mechanism of action of Fc fusion technology (63% relative increase, p<.001), patient counseling when switching to an extended half-life factor replacement (100%, P=.008), joint health in hemophilia (340% relative increase, P<.05), and incidence of inhibitors (227% relative increase, p<.05).Confidence in when to use prophylaxis increased post-educational exposure (7.3% mean confidence shift using a 7-point Likert scale) as measured in 3 of the 6 activities. Areas where knowledge gaps remained, as evidenced by >15% incorrect answers post-education, included: adherence with prophylaxis, outcomes for children and adults with severe hemophilia A receiving prophylaxis vs episodic treatment, clinical data from recent studies with new extended half-life factor products in terms of efficacy, tolerability, and risk of inhibitor development in persons of different ages and risk settings, and the potential place of extended half-life factor products in the strategy for the care of individuals with hemophilia A and B.This study demonstrates the success of a targeted online hemophilia educational curriculum using text and video formats in improving the knowledge and confidence of hematologists/oncologists who treat patients with hemophilia, while also identifying remaining educational needs for future education. DisclosuresVan Laar:Medscape LLC: Employment. Pipe:CSL Behring: Consultancy; Bayer: Consultancy; American Thrombosis and Hemostasis Network: Other: Chair of the Board of Directors; National Hemophilia Foundation: Other: member of the Medical and Scientific Advisory Committee; Novo Nordisk: Consultancy; Baxter: Consultancy; Biogen Idec Inc: Consultancy.