SESSION TITLE: Patient Safety
SESSION TYPE: Original Investigation Slide
PRESENTED ON: Tuesday, October 29, 2013 at 02:45 PM - 04:15 PM
PURPOSE: The pulmonary embolism rule-out criteria (PERC) is an eight-variable clinical prediction model that identifies patients at low risk for pulmonary embolism (PE) in order to prevent unnecessary diagnostic testing in the evaluation of suspected PE in the emergency department (ED). The objective of this study was to determine PERC’s safety and diagnostic utility in our institution’s ED population.
METHODS: We performed a retrospective analysis on consecutive patients evaluated with computed tomography angiography (CTA) for suspicion of PE at our institution’s ED during the dates 1/1/2011 to 12/31/2011. Patients negative for all eight PERC criteria [i.e., “PERC (-)”] were considered to be at very low risk for PE, independent of physician gestalt. All data was analyzed using SPSS (version 20.0) in order to calculate the variables of interest and their respective 95% confidence intervals (95% CI).
RESULTS: During the 12-month study period, 729 subjects were evaluated with CTA for suspicion of PE. The prevalence of PE was 4.5%. Ten subjects were excluded because of non-diagnostic imaging studies (e.g., malfunction of the CT scanner or inappropriate timing of contrast). After exclusion, 719 subjects were available for analysis. Subjects’ mean age was 47 years (SD +/- 13, range 18-87). Females represented 61% of the population. Sixty-two percent were African-American, 32% White, and 6% other (self-identified). When PERC (-) is used as an independent diagnostic test to exclude the presence of PE, it had a sensitivity of 96.9% (95% CI, 84.3-99.4%), NPV of 98.7% (95% CI, 93.4-99.8%), and negative LR of 0.262 (95% CI, 0.014-1.544).
CONCLUSIONS: Use of PERC could have safely avoided 11.5% of CTAs, reducing potential patient harm, healthcare costs, and unnecessary diagnostic testing. Consistent with prior studies, PERC can be safely used to identify low risk patients for whom further testing can be deferred.
CLINICAL IMPLICATIONS: This simple bedside tool can be used with confidence (<2% false negative rate) in patients with a low pre-test probability for PE, thereby reducing unnecessary testing.
DISCLOSURE: The following authors have nothing to disclose: Andrew Bozarth, Navin Bajaj, Margaret Wessling, Dustin Keffer, Shais Jallu, Gary Salzman
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