title: Risk stratifying emergency department patients with acute pulmonary embolism: Does the simplified Pulmonary Embolism Severity Index perform as well as the original?
abstract: BACKGROUND
  The Pulmonary Embolism Severity Index (PESI) is a validated prognostic score to estimate the 30-day mortality of emergency department (ED) patients with acute pulmonary embolism (PE). A simplified version (sPESI) was derived but has not been as well studied in the U.S. We sought to validate both indices in a community hospital setting in the U.S. and compare their performance in predicting 30-day all-cause mortality and classification of cases into low-risk and higher-risk categories.
  
  
  METHODS
  This retrospective cohort study included adults with acute objectively confirmed PE from 1/2013 to 4/2015 across 21 community EDs. We evaluated the misclassification rate of the sPESI compared with the PESI. We assessed accuracy of both indices with regard to 30-day mortality.
  
  
  RESULTS
  Among 3006 cases of acute PE, the 30-day all-cause mortality rate was 4.4%. The sPESI performed as well as the PESI in identifying low-risk patients: both had similar sensitivities, negative predictive values, and negative likelihood ratios. The sPESI, however, classified a smaller proportion of patients as low risk than the PESI (27.5% vs. 41.0%), but with similar low-risk mortality rates (<1%). Compared with the PESI, the sPESI overclassified 443 low-risk patients (14.7%) as higher risk, yet their 30-day mortality was 0.7%. The sPESI underclassified 100 higher-risk patients (3.3%) as low risk who also had a low mortality rate (1.0%).
  
  
  CONCLUSIONS
  Both indices identified patients with PE who were at low risk for 30-day mortality. The sPESI, however, misclassified a significant number of low-mortality patients as higher risk, which could lead to unnecessary hospitalizations.
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Kaiser Permanente Northern California Division of Research, Oakland, California, United States; Department of Emergency Medicine, Kaiser Permanente Sacramento Medical Center, Sacramento, California, United States. Electronic address: drvinson@ucdavis.edu.
authors.forename: David R
authors.initials: DR
authors.lastname: Vinson
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Kaiser Permanente Northern California Division of Research, Oakland, California, United States; Department of Emergency Medicine, Kaiser Permanente San Rafael Medical Center, San Rafael, California, United States.
authors.forename: Dustin W
authors.initials: DW
authors.lastname: Ballard
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Department of Emergency Medicine, Kaiser Permanente Oakland Medical Center, Oakland, California, United States.
authors.forename: Dustin G
authors.initials: DG
authors.lastname: Mark
authors.affiliation: Kaiser Permanente Northern California Division of Research, Oakland, California, United States.
authors.forename: Jie
authors.initials: J
authors.lastname: Huang
authors.affiliation: Kaiser Permanente Northern California Division of Research, Oakland, California, United States.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Reed
authors.affiliation: Kaiser Permanente Northern California Division of Research, Oakland, California, United States.
authors.forename: Adina S
authors.initials: AS
authors.lastname: Rauchwerger
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Division of Palliative Care, University of California, San Francisco, San Francisco, California, United States.
authors.forename: David H
authors.initials: DH
authors.lastname: Wang
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Department of Emergency Medicine, Kaiser Permanente Santa Clara Medical Center, Santa Clara, California, United States.
authors.forename: James S
authors.initials: JS
authors.lastname: Lin
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Department of Emergency Medicine, Kaiser Permanente San Leandro Medical Center, San Leandro, California, United States.
authors.forename: Mamata V
authors.initials: MV
authors.lastname: Kene
authors.affiliation: Department of Emergency Medicine, Kaiser Permanente Los Angeles Medical Center, Los Angeles, California, United States.
authors.forename: Tamara S
authors.initials: TS
authors.lastname: Pleshakov
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Department of Emergency Medicine, Kaiser Permanente Oakland Medical Center, Oakland, California, United States.
authors.forename: Dana K
authors.initials: DK
authors.lastname: Sax
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Department of Emergency Medicine, Kaiser Permanente San Rafael Medical Center, San Rafael, California, United States.
authors.forename: Jordan M
authors.initials: JM
authors.lastname: Sax
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Department of Emergency Medicine, Kaiser Permanente San Francisco Medical Center, San Francisco, California, United States.
authors.forename: D Ian
authors.initials: DI
authors.lastname: McLachlan
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Kaiser Permanente Northern California Division of Research, Oakland, California, United States; Department of Emergency Medicine, Kaiser Permanente Oakland Medical Center, Oakland, California, United States.
authors.forename: Cyrus K
authors.initials: CK
authors.lastname: Yamin
authors.affiliation: Department of Emergency Medicine, Kaiser Permanente San Diego Medical Center, San Diego, California, United States.
authors.forename: Clifford J
authors.initials: CJ
authors.lastname: Swap
authors.affiliation: University of Michigan Medical School, Ann Arbor, MI, United States.
authors.forename: Hilary R
authors.initials: HR
authors.lastname: Iskin
authors.affiliation: University of Cincinnati College of Medicine, Cincinnati, OH, United States.
authors.forename: Ridhima
authors.initials: R
authors.lastname: Vemula
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Department of Emergency Medicine, Kaiser Permanente Roseville Medical Center, Roseville, California, United States.
authors.forename: Bethany S
authors.initials: BS
authors.lastname: Fleming
authors.affiliation: The Permanente Medical Group, Oakland, California, United States; Department of Emergency Medicine, Kaiser Permanente South Sacramento Medical Center, Sacramento, California, United States.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Elms
authors.affiliation: Department of General Internal Medicine, Bern University Hospital, Bern, Switzerland.
authors.forename: Drahomir
authors.initials: D
authors.lastname: Aujesky
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003661:Decision Support Techniques; D004636:Emergency Service, Hospital; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011655:Pulmonary Embolism / Q000175:diagnosis* / Q000401:mortality; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index
keywords: Clinical prediction rule; Decision support techniques; Prognosis; Pulmonary embolism; Risk assessment; Severity of illness index