ACCURACY OF TOURNIQUET TEST FOR THE DIAGNOSIS OF DENGUE INFECTION

Tourniquet Test for The Diagnosis Of Dengue

Abstract

Objective: This study was carried out to determine the accuracy of tourniquet test for diagnosis of dengue infection in patients with clinically suspected dengue fever, keeping dengue IgM/IgG as gold standard.
Study Design: Cross sectional validation study.
Place and Duration of Study: The study was carried out at Military Hospital Rawalpindi and Combined Military Hospital Malir Cantt Karachi from Jun 2011 to Dec 2013.
Material and Methods: One hundred and sixty cases of undetermined fever of two to seven days duration were enrolled by non-probability convenience sampling to determine the accuracy of tourniquet test. Previously diagnosed patients of chronic liver disease, chronic renal failure and those on anticoagulant /anti-platelet therapy were excluded. The dengue tourniquet test was performed according to the standardized method within 24 hours of admission, and the results of tourniquet test were compared with dengue IgM/IgG as gold standard.
Results: Diagnostic accuracy of tourniquet test for diagnosis of dengue infection in patients with clinically suspected dengue fever, keeping dengue IgM/IgG as gold standard showed 26.88%(95% CI = 20.01- 33.75%) were true positive, 7.5%(95% CI=3.42–11.58%) were false positive, 46.25% (95% CI=38.52–53.98%) were true negative and 19.38% (95% CI =13.26–25.5%) were false negative, whereas sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy was calculated as 58.11%, 86.05%, 78.18%, 70.48%, and 73.12% respectively.
Conclusion: In view of the results of the current study demonstrating high specificity and diagnostic accuracy, the tourniquet test may be used routinely in clinical practice. Comparatively lower sensitivity may be related to time of presentation, which needs to be further evaluated.