Validation of a clinical prognostic model to identify low‐risk patients with pulmonary embolism

Abstract

Abstract.: Objective. To validate the Pulmonary Embolism Severity Index (PESI), a clinical prognostic model which identifies low‐risk patients with pulmonary embolism (PE). Design. Validation study using prospectively collected data. Setting. A total of 119 European hospitals. Subjects. A total of 899 patients diagnosed with PE. Intervention. The PESI uses 11 clinical factors to stratify patients with PE into five classes (I–V) of increasing risk of mortality. We calculated the PESI risk class for each patient and the proportion of patients classified as low‐risk (classes I and II). The outcomes were overall and PE‐specific mortality for low‐risk patients at 3 months after presentation. We calculated the sensitivity, specificity and predictive values to predict overall and PE‐specific mortality and the discriminatory power using the area under the receiver operating characteristic curve. Results. Overall and PE‐specific mortality was 6.5% (58/899) and 2.3% (21/899) respectively. Forty‐seven per cent of patients (426/899) were classified as low‐risk. Low‐risk patients had an overall mortality of only 1.2% (5/426) and a PE‐specific mortality of 0.7% (3/426). The sensitivity was 91 [95% confidence interval (CI): 81–97%] and the negative predictive value was 99% (95% CI: 97–100%) for overall mortality. The sensitivity was 86% (95% CI: 64–97%) and the negative predictive value was 99% (95% CI: 98–100%) for PE‐specific mortality. The areas under the receiver operating characteristic curve for overall and PE‐specific mortality were 0.80 (95% CI: 0.75–0.86) and 0.77 (95% CI: 0.68–0.86) respectively. Conclusions. This validation study confirms that the PESI reliably identifies low‐risk patients with PE who are potential candidates for less costly outpatient treatment.