More than 80,000 youth in Canada undergo surgery each year. Of those youth undergoing major surgery, 20% will develop chronic postsurgical pain (CPSP). Coordinated and multidisciplinary outpatient pain services are being developed across Canada to prevent and treat CPSP. A developmentally appropriate screening measure is needed for early identification of youth at risk for CPSP to guide management and referral for to such services. Dr. Rosenbloom will present results from a CIHR funded multi-phased project to co-develop and validate a pediatric CPSP risk measure (PAIN-RISK; youth and parent versions). The COsensus-based Standards for the selection of health Measurement Instruments (COSMIN) is used to guide the phases. Phase 1 includes identifying risk factors through an updated systematic review on the prevalence and risk factors of CPSP (PROSPERO: CRD42022306340). A total of 2,877 abstracts were screened and 37 articles were included. Key data was extracted on identified risk factors and validated measures used to assess risk factors. Phase 2 includes refining risk factor constructs and creating an item pool from the validated measures in phase one. A modified Delphi procedure will be used refine risk factor constructs and an initial item pool (completion: Summer 2023). Future phases will focus on the validation of the PAIN-RISK measure.