Tourniquet Test for Dengue Diagnosis: Systematic Review and Meta-analysis of Diagnostic Test Accuracy

Background: Dengue fever is a ubiquitous arboviral infection in tropical and sub-tropical regions, whose incidence has increased over recent decades. In the absence of a rapid point of care test, the clinical diagnosis of dengue is complex. The World Health Organisation has outlined diagnostic criteria for making the diagnosis of dengue infection, which includes the use of the tourniquet test (TT). Purpose: To assess the quality of the evidence supporting the use of the TT and perform a diagnostic accuracy meta-analysis comparing the TT to antibody response measured by ELISA. Data Sources: A comprehensive literature search was conducted in the following databases to April, 2016: MEDLINE (PubMed), EMBASE, Cochrane Central Register of Controlled Trials, BIOSIS, Web of Science, SCOPUS. Study Selection: Studies comparing the diagnostic accuracy of the tourniquet test with ELISA for the diagnosis of dengue were included. Data Extraction: Two independent authors extracted data using a standardized form. Data Synthesis: A total of 16 studies with 28,739 participants were included in the meta-analysis. Pooled sensitivity for dengue diagnosis by TT was 58% (95% Confidence Interval (CI), 43%-71%) and the specificity was 71% (95% CI, 60%-80%). In the subgroup analysis sensitivity for non-severe dengue diagnosis was 55% (95% CI, 52%-59%) and the specificity was 63% (95% CI, 60%-66%), whilst sensitivity for dengue hemorrhagic fever diagnosis was 62% (95% CI, 53%-71%) and the specificity was 60% (95% CI, 48%-70%). Receiver-operator characteristics demonstrated a test accuracy (AUC) of 0.70 (95% CI, 0.66–0.74). Conclusion: The tourniquet test is widely used in resource poor settings despite currently available evidence demonstrating only a marginal benefit in making a diagnosis of dengue infection alone. Registration: The protocol for this systematic review was registered at PROSPERO: CRD42015020323. Author Summary: Dengue is an infectious disease transmitted by mosquitoes in the Tropics. There are 2.5 billion people around the world at risk. Dengue presents as an acute febrile illness with symptoms including headache, bone or joint and muscular pains and rash. The objective of this study is to perform a diagnostic accuracy meta-analysis comparing the use of the Tourniquet Test (TT) to a laboratory assay standard (ELISA) for making a diagnosis of dengue infection. A comprehensive literature search (to April, 2016) was conducted to map and assess the quality of the available evidence, using the following databases: MEDLINE (PubMed), EMBASE, Cochrane Central Register of Controlled Trials, BIOSIS, Web of Science, SCOPUS. We included 16 studies with 28,739 participants in the meta-analysis. Pooled sensitivity for dengue diagnosis by TT was 58% (95% Confidence Interval (CI), 43%-71%) and the specificity was 71% (95% CI, 60%-80%). In the pooled subgroup analysis sensitivity for dengue fever diagnosis was 55% (95% CI, 52%-59%) and the specificity was 63% (95% CI, 60%-66%). The tourniquet test is widely used in resource poor settings despite currently available evidence demonstrating only a marginal benefit in making a diagnosis of dengue infection alone.