Abstract Background/Aims Shared decision-making (SDM) is a joint process in which a person and healthcare professional work together to reach decisions about care. The iFraP (Improving uptake of Fracture Prevention drug treatments) intervention comprises computerised decision aid (DA), Fracture Liaison Service (FLS) clinician training package, and information resources to support SDM about osteoporosis medicines. This abstract details our multi-method approach to develop this intervention. Methods Intervention development was underpinned by the Medical Research Council guidelines for development of complex interventions. Four studies guided intervention prototype development, including (1) an evidence synthesis of existing osteoporosis DAs to examine quality and effectiveness; (2) a review of patient information about osteoporosis to evaluate quality and optimal language for talking about osteoporosis; (3) a Delphi consensus survey with patients, carers, and health professionals to gain consensus on intervention content, informed by an evidence review of relevant clinical guidelines and behavioural theories; (4) and focus groups and interviews with patients recently attending FLS, FLS clinicians and general practitioners (GPs) to explore current FLS practice, and barriers and facilitators to change. Expert stakeholders and public contributors informed each sub-study. Results Studies one and two informed design of the iFraP computerised DA. Evidence reviews of existing osteoporosis DAs and patient information found that they did not meet patient needs and identified poor readability, variable quality, and unbalanced and confusing content. Public contributors preferred DAs which were individualised, and together with expert stakeholders, supported the development of understandable explanations of osteoporosis and osteoporosis medicines to include in iFraP resources. Study three identified essential components of the FLS consultation which directly informed DA content. Study four identified the need for complementary iFraP information resources, training, and potential barriers to iFraP DA use. Patients expressed that they did not feel adequately prepared for their FLS consultation, leading to the development of an enhanced leaflet to accompany their FLS appointment letter. Patients, FLS clinicians, and GPs all expressed the need for a patient-friendly individualised summary of the FLS consultation, to facilitate consistent information across services and reinforce FLS messaging. This finding informed development of the iFraP Bone Health Record, an individualised, easy-read PDF print-out of the iFraP DA. FLS clinicians identified training needs relating to communicating risk, involving patients in decisions and clinical decision-making. Barriers to use included concerns that the DA would increase consultation duration, and that SDM may undermine their goal to facilitate medicine adherence. Identified barriers to use and training needs informed the content and delivery of the interactive eLearning and role play session, with consideration of theoretically-informed behaviour change techniques. Conclusion The iFraP complex intervention development work demonstrates the use of multiple methods to develop an evidence-based and theoretically-driven intervention in-preparation for testing. Disclosure L. Bullock: None. J. Fleming: None. E.M. Clark: None. S. Leyland: None. S. Thomas: Grants/research support; ST owns Prescribing Decision Support Ltd that developed the iFraP decision aid. C. Gidlow: None. T.W. O'Neill: Grants/research support; TON is supported by the NIHR Manchester Biomedical Research Centre. C.P. Iglesias-Urrutia: None. A. Hawarden: Grants/research support; AH is funded by a Versus Arthritis Clinical Research Fellowship (reference 22726). F. Manning: None. J. Protheroe: None. J. Lefroy: None. S. Ryan: None. R. Horne: None. C.D. Mallen: Grants/research support; CM is funded by the NIHR Applied Research Collaboration West Midlands and the NIHR School for Primary Care Research. C. Jinks: Grants/research support; CJ is part funded by NIHR Applied Research Collaboration (ARC) West Midlands. Z. Paskins: Consultancies; ZP has received consultancy fees from UCB Pharma. Grants/research support; ZP is funded by the National Institute for Health Research (NIHR) [Clinician Scientist Award (CS-2018-18-ST2-010)/NIHR Academy].