Prospective Multicenter Study of Quantitative Pretest Probability Assessment to Exclude Acute Coronary Syndrome for Patients Evaluated in Emergency Department Chest Pain Units

Alice M. Mitchell, J. Lee Garvey, Abhinav Chandra, Deborah Diercks, Charles V. Pollack, Jeffrey A. Kline

Research output: Contribution to journalArticle

56 Scopus citations


Study objective: We compare the diagnostic accuracy of 3 methods-attribute matching, physician's written unstructured estimate, and a logistic regression formula (Acute Coronary Insufficiency-Time Insensitive Predictive Instrument, ACI-TIPI)-of estimating a very low pretest probability (≤2%) for acute coronary syndromes in emergency department (ED) patients evaluated in chest pain units. Methods: We prospectively studied 1,114 consecutive patients from 3 academic EDs, evaluated for acute coronary syndrome. Physicians collected data required for pretest probability assessment before protocol-driven chest pain unit testing. A pretest probability greater than 2% was considered "test positive." The criterion standard was the outcome of acute coronary syndrome (death, myocardial infarction, revascularization, or >60% stenosis prompting new treatment) within 45 days, adjudicated by 3 independent reviewers. Results: Fifty-one of 1,114 enrolled patients (4.5%; 95% confidence interval [CI] 3.4% to 6.0%) developed acute coronary syndrome within 45 days, including 4 of 991 (0.4%; 95% CI 0.1% to 1.0%) patients, discharged after a negative chest pain unit evaluation result, who developed acute coronary syndrome. Unstructured estimate identified 293 patients with pretest probability less than or equal to 2%, 2 had acute coronary syndrome, yielding sensitivity of 96.1% (95% CI 86.5% to 99.5%) and specificity of 27.4% (95% CI 24.7% to 30.2%). Attribute matching identified 304 patients with pretest probability less than or equal to 2%; 1 had acute coronary syndrome, yielding a sensitivity of 98.0% (95% CI 89.6% to 99.9%) and a specificity of 26.1% (95% CI 23.6% to 28.7%). ACI-TIPI identified 56 patients; none had acute coronary syndrome, yielding sensitivity of 100% (95% CI 93.0% to 100%) and specificity of 6.1% (95% CI 4.7% to 7.9%). Conclusion: In a low-risk ED population with symptoms suggestive of acute coronary syndrome, patients with a quantitative pretest probability less than or equal to 2%, determined by attribute matching, unstructured estimate, or logistic regression, may not require additional diagnostic testing.

Original languageEnglish (US)
Pages (from-to)447.e1-447
JournalAnnals of emergency medicine
Issue number5
StatePublished - May 1 2006


ASJC Scopus subject areas

  • Emergency Medicine

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