Abstract BackgroundNHS Health Check (HC) is a Cardiovascular Disease (CVD) risk assessment programme for adults in England aged 40-74 years. There is evidence that the % 10-year risk score (QRISK2) currently communicated, is not easily understood by patients or practitioners, leading to interest in new risk calculators like JBS3, which estimates lifetime risk, has greater functionality and visual displays. PurposeNovel application of research methods to explore practitioner and patient perceptions of CVD risk when using JBS3 or QRISK2, how patients respond, the associated practitioner advice/treatment and resulting patient intentions. MethodologyRICO is a qualitative study with quantitative process evaluation. Twelve general practices will be randomised to use QRISK2 (n=6) or JBS3 to communicate CVD risk in HCs. A random, stratified sample of 20 eligible patients will be recruited per practice. Data collection and analysis include:240 video-recorded HCs coded to quantify consultation content (e.g., time discussing risk).144 recordings qualitatively analysed using deductive Thematic Analysis (framework derived from Protection Motivation Theory).Semi-structured, one-to-one video-stimulated recall interviews with patients (n=48) and practitioners (n=18-24) using HC video excerpts to prompt reflection, with inductive Thematic Analysis.Medical record reviews (12 weeks post-HC) to identify consultation outcomes (e.g., referrals, medication).Case study analysis (n=10) combining data from 1-4. Results and conclusionsThis study will provide insight through novel application of research methods to the potential benefit of innovative CVD risk communication tools in HCs. This will include how QRISK2 and JBS3 are used, patient and practitioner understanding and perceptions of CVD risk, patient response and intentions regarding health-protective behaviours, and underlying mechanisms.Data collection will start January 2018. Study methods and progress will be presented. Funding This project is funded by the National Institute for Health Research HTA Programme (project number 15/170/02).