Light-emitting diode fluorescence microscopy for tuberculosis diagnosis: a meta-analysis

Eva Chang is a graduate of the Europubhealth (EPH) program and studied at ScHARR in 2012-2013. Prior to pursuing her MPH degrees, Eva had years of industry experience in monitoring clinical trials. Long interested in the multidrug-resistant tuberculosis (MDR-TB) crisis in Central Asia, Eva started the EPH program to study epidemiology and operational research methods.
Eva is currently working as a Trial Manager at the Harvard Medical School for a clinical trial that aims to test for shorter and simpler treatment regimens for MDR-TB patients.

The focus of Eva's project work was light-emitting diode fluorescence microscopy for tuberculosis diagnosis. Along with her co-authors Eva has recently published her work in the European Respiratory Journal.

Light-emitting diode fluorescence microscopy (LED-FM) is recommended by the World Health Organization to replace conventional Ziehl–Neelsen microscopy for pulmonary tuberculosis diagnosis. Uptake of LED-FM has been slow. One reason is its reported loss of specificity compared with Ziehl–Neelsen microscopy. We aimed to determine the diagnostic accuracy of LED-FM for tuberculosis detection and explore potential factors that might affect its performance.

A comprehensive search strategy based on pre-specified criteria was employed to identify eligible studies between January 1, 2000 and April 1, 2014 in 11 databases. Standardised study selection, data extraction and quality assessment were conducted. Pooled sensitivity and specificity of LED-FM using culture as the reference standard were estimated through meta-analyses using a bivariate random-effects model. Investigation of heterogeneity was performed by subgroup analyses.

We identified 12 unique studies, half of which were from peripheral healthcare facilities. LED-FM achieved a pooled sensitivity of 66.9% (95% CI 60.5–72.7) and pooled specificity of 96.8% (95% CI 93.1–98.6). A pooled sensitivity of 53.0% (95% CI 42.8–63.0) and pooled specificity of 96.1% (95% CI 86.0–99.0) were obtained by LED-FM among HIV-infected patients. Study methodology factors and differences in the LED-FM procedure or device could also affect the performance.

LED-FM specificity is high and should not be a barrier to device introduction, particularly among peripheral healthcare settings where this technology is meant to be used. Sensitivity is reduced in HIV-infected patients.

Reproduced with permission of the European Respiratory Society ©: European Respiratory Journal Dec 2015, DOI: 10.1183/13993003.00978-2015