Modifiers of the effectiveness of point-of-care troponin testing and determinants of concordance between diagnostic pathway recommendations and disposition in patients with chest pain: a post hoc analysis of a randomised controlled trial

Introduction While point-of-care (POC) high-sensitivity cardiac troponin (hs-cTn) testing has the potential to reduce emergency department (ED) length of stay (LOS), evidence of real world effectiveness is lacking. Our objective was to examine factors that influence the real world effectiveness of POC hs-cTn-based accelerated diagnostic protocols (ADPs) in reducing ED LOS. Methods This is a post hoc analysis from the “Aiming towards evidence-based interpretation of cardiac biomarkers in patients presenting with chest pain using POC testing” (WESTCOR-POC) study which included 1494 consecutive patients with suspected acute coronary syndrome presenting to the ED at a moderately sized hospital in Norway. Patients were randomised to receive hs-cTn measurements at admission and after 1 hour either by POC or central laboratory testing. This post hoc analysis examines factors affecting the effectiveness of a POC-based ADP and predictors of non-ADP-concordant disposition. Both outcomes were assessed using regression models, with significance level set at p60 years (OR 2.3, 95% CI 1.4 to 3.7, p=0.001), high triage category (OR 1.9, 95% CI 1.2 to 3.0, p=0.003) and suspected serious differential diagnosis (OR 5.9, 95% 3.5 to 9.9, p