Infectious Disease
Establishing a clinical decision rule of severe acute respiratory syndrome at the emergency department

https://doi.org/10.1016/j.annemergmed.2003.08.002Get rights and content

Abstract

Study objective

In the absence of reliable rapid confirmatory tests during severe acute respiratory syndrome (SARS) endemics, we designed a 2-phase cohort study to establish a scoring system for SARS and to evaluate whether it could improve the sensitivity and specificity of the World Health Organization (WHO) criteria.

Methods

According to the clinical characteristics and initial laboratory findings of 175 suspected cases defined by the WHO criteria (20 confirmed as cases of SARS) in 3 university teaching hospitals in Taipei between March 1 and April 20, 2003, the scoring system for SARS was designed by multivariate analysis and stepwise logistic regression as the simple arithmetic sum of point values assigned to 7 parameters. We thereafter applied the scoring system for SARS to the consecutive 232 patients (the validation group) who met the WHO criteria of suspected cases from April 21 to May 22, 2003. Final diagnosis of SARS was determined by the results of real-time polymerase chain reaction and paired serum.

Results

The scoring system for SARS was defined as radiographic findings of multilobar or bilateral infiltrates (3 points), sputum monocyte predominance (3 points), lymphocytopenia (2 points), history of exposure (1 point), lactate dehydrogenase more than 450 U/L (1 point), C-reactive protein more than 5.0 mg/dL (1 point), and activated partial prothrombin time more than 40 seconds (1 point). Of the validation group, 60 patients (group A) were confirmed as having cases of SARS, and the other 172 (group B) patients tested negative for SARS. The total points of the scoring system for SARS at initial presentation were significantly higher in the SARS group (median 9; range 6 to 11) than in the non-SARS group (median 4; range 3 to 7; P<.001). At the cutoff value of 6 points, the sensitivity and specificity of the scoring system for SARS in diagnosing SARS were 100% and 93%, respectively. The positive and negative predictive values of the scoring system for SARS were 83% and 100%, respectively.

Conclusion

The scoring system for SARS can provide a rapid and reliable clinical decision to help emergency physicians detect cases of SARS more accurately in the endemic area.

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Editor's note: This article was first published on Annals' Web site (www.mosby.com/AnnEmergMed) on October 9, 2003. Articles of particular interest are published on the Web site in advance of their appearance in the print journal. In the future, an increasing percentage of our content will be published first on the Web, predating the print publication as a service to our readers.

Author contributions: All authors jointly collected clinical data of the patients. TLW and CH designed the study and revised the manuscript. TNJ, CHH, and SJK assisted with constructing the analytic data file. DH and CML were responsible for statistical analysis. TLW takes responsibility for the paper as a whole.

The authors report this study did not receive any outside funding or support.

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