biostudies-literatureVialard FFonds de Recherche du Québec - SantéIndia-Canada Centre for Innovative Multidisciplinary Partnerships to Accelerate Community Transformation and SustainabilityCanadian Institutes of Health Research467-473https://www.ebi.ac.uk/biostudies/studies/S-EPMC12573389biostudies-literatureUnknown101(7)<h4>Objectives</h4>Across Canada, in the last decade, incidence rates of sexually transmitted and blood-borne infections (STBBI) have peaked (syphilis) or plateaued (hepatitis C virus (HCV) and HIV). Key populations (gay, bisexual and other men who have sex with men, trans and gender-diverse people, and people who use injection drugs) are at greater risk for these STBBIs, so correctly predicting risk before screening potentially infected individuals is crucial. We developed and validated a diagnostic clinical risk prediction model (CRPM) estimating HIV, HCV and syphilis risk for two key populations in two Canadian provinces.<h4>Methods</h4>We used 20 variables and STBBI test results from a cross-sectional study evaluating multiplexed testing (detection of coinfections) in New Brunswick andSexually transmitted infectionsDeveloping and validating a Bayesian clinical risk prediction model for three sexually transmitted infections in key populations from two Canadian provinces.PMC12573389PJT1531493241542528453072Materniak SDumont Blais AVialard FPant Pai NBartlett SWebster DNair SZhang QfalseDeveloping and validating a Bayesian clinical risk prediction model for three sexually transmitted infections in key populations from two Canadian provinces.<h4>Objectives</h4>Across Canada, in the last decade, incidence rates of sexually transmitted and blood-borne infections (STBBI) have peaked (syphilis) or plateaued (hepatitis C virus (HCV) and HIV). Key populations (gay, bisexual and other men who have sex with men, trans and gender-diverse people, and people who use injection drugs) are at greater risk for these STBBIs, so correctly predicting risk before screening potentially infected individuals is crucial. We developed and validated a diagnostic clinical risk prediction model (CRPM) estimating HIV, HCV and syphilis risk for two key populations in two Canadian provinces.<h4>Methods</h4>We used 20 variables and STBBI test results from a cross-sectional study evaluating multiplexed testing (detection of coinfections) in New Brunswick and2025-01-01T00:00:00Z2025 Oct2026-06-05T09:46:27.304Z2026-05-15T03:12:46.323ZS-EPMC125733894027440210.1136/sextrans-2024-056286