Comparing the pulmonary embolism severity index and the prognosis in pulmonary embolism scores as risk stratification tools

BACKGROUND: Multiple risk stratification scoring systems exist to forecast outcomes in patients with acute pulmonary embolism (PE). OBJECTIVE: We evaluated the comparative validity of the PE severity index (PESI) and the prognosis in pulmonary embolism (PREP) scores to predict mortality in acute PE. DESIGN: Retrospective observational cohort study. SETTING: Washington Hospital Center, Washington, DC. PATIENTS: Consecutive adults (aged >18 years) diagnosed with acute PE. INTERVENTION: The PESI and PREP scores were calculated. MEASUREMENTS: Raw PESI scores were segregated into risk class (I-V) and then dichotomized into low (I-II) versus high (III-V) risk groups; the raw PREP scores were divided into low (0-7) versus high (>7) risk groups. The primary endpoint was 30-day and 90-day mortality. We determined the negative predictive value and computed the area under the receiver operating characteristics (AUROC) curves to compare the ability of these scoring tools. RESULTS: The cohort consisted of 302 subjects. Thirty-day mortality was 3.0%, and 4.0% died within 90 days. The PESI and the PREP performed similarly (PESI AUROC: 0.858 [95% confidence interval (CI), 0.773-0.943] vs 0.719 [95% CI, 0.563-0.875] for PREP). Segregating these scores into risk categories did not affect their discriminatory power (AUROC: 0.684 [95% CI, 0.559-0.810] for PESI and 0.790 [95% CI, 0.679-0.903] for PREP). The negative predictive value for death of being classified as low risk by the PESI or PREP was 100% and 99%, respectively. CONCLUSIONS: The PREP score performed comparably to the PESI score for identifying PE patients at low risk for short-term and intermediate-term mortality. Journal of Hospital Medicine 2012;7:22-27. (C) 2011 Society of Hospital Medicine