Pulmonary embolism rule-out decision-making tools for patients aged 35 years or younger in hospital emergency departments: a post-hoc analysis of performance in 3 prospective cohorts

Objectives. To assess the performance of the Pulmonary Embolism Rule-out Criteria (PERC) and the age-modified PERC-35 tool in hospital emergency departments (EDs) for evaluating patients aged 35 years or younger. A secondary aim was to assess other decision-making criteria. Method. Post-hoc analysis of 3 European cohort studies. We included data for patients aged 35 years or younger suspected of PE who were followed for 3 months. The safety and efficacy of applying the PERC and PERC-35 were assessed with the diagnostic error rate (failure to detect PE) and the proportion of patients in whom a diagnosis of PE was ruled out. We also assessed the safety and efficacy of applying the YEARS and PEGeD criteria. Results. Data for 1235 patients aged 35 years or younger were analyzed. Twenty-two (1.8%; 95% CI, 1.2%-2.7%) PE cases were diagnosed at 3 months. Six (1.0%; 95% CI, 0.5%-2.2%) and 5 (0.9%; 95% CI, 0.4%-2.1%) PE cases were not diagnosed by the PERC and PERC-35 tools, respectively. These tools allowed PE to be ruled out in 591 (48.2%; 95% CI, 45.4%-51.0%) and 554 (46.2%; 95% CI, 43.4%-49.0%) cases, respectively. The error rates of the YEARS and PEGeD criteria, respectively, were 0.4% (95% CI, 0.1%-1.1%) and 0.5% (95% CI, 0.2%-1.2%); their efficacy was similar. Conclusions. The safety and efficacy profiles of the PERC and PERC-35 algorithms were similar in patients aged 35 years or younger. However, the large confidence intervals we report do not allow us to confirm the safety of using the tools in patients in this age group.