P3-S5.04 The diagnostic accuracy of rapid point of care tests used to diagnose Hepatitis B: a Bayesian meta-analysis
Authors: Shivkumar S , Jafari Y , Lambert G , Claessens C , Klein M , Martinez-Cajas J , Peeling R , Joseph L , Pai N Pant 
Published: July 2011

Background

More than 350 million people are infected with the Hepatitis B virus worldwide, with four million new cases every year. The prevalence of the Hepatitis B virus is highest in developing settings where laboratory equipment and diagnostic resources are limited. This creates a need for rapid point-of-care testing in order to screen blood donors and ensure timely diagnosis and treatment of infected individuals. Although studies have been conducted examining the accuracy of different tests, there has not been a synthesis of the available global evidence, or an assessment of the quality of evidence to date.

Objective

We conducted a systematic review of the global literature examining the sensitivity and specificity of rapid point-of-care tests used to diagnose Hepatitis B, and meta-analysed the data. Additionally, we conducted a critical appraisal of the quality of included studies.

Methods

Two reviewers conducted independent searches of five databases between the years of 1990 and 2010 for global evidence. Meta-analysis was performed grouping studies based on whether the index test identified HBsAg, both HBs and eAg, or antibody to HbsAg. We used Bayesian meta-analysis, accounting for the fact that all of the studies used imperfect reference standards (sensitivity and specificity assumed to range between 90% and 100%). The quality of all included full-text studies was assessed using the QUADAS and STARD checklists.

Results

A total of 17 studies were identified, of which 13 were from developing countries and which investigated 22 different index tests. When studies were pooled, the Determine HBsAg test showed a combined sensitivity of 98.76% and a specificity of 99.94%. Other HBsAg tests showed a lower combined sensitivity (96.77%) but comparable specificity (99.89%). The Amrad HBs+eAg test showed a combined sensitivity of 98.04% and a specificity of 99.04%, while the tests detecting antibody to HBsAg showed a combined sensitivity of 99.77% and a specificity of 96.08%. Studies were of poor-moderate quality with QUADAS scores ranging from 3 to 10/14 and STARD scores ranging from 7 to 14/25 see Abstract P3-S5.04 table 1.

Abstract P3-S5.04 Table 1

Results from bayesian meta-analysis of diagnostic accuracy of hepatitis B point-of-care tests

Program in R: Hierarchical modelAssuming perfect reference standard (100%)Assuming imperfect reference standard (90%–100%)SubgroupSensitivity (95% CI)Specificity (95% CI)Sensitivity (95% CI)Specificity (95% CI)HBsAg94.76% (90.08 to 98.23%)99.54% (99.03 to 99.953%)96.77% (92.92 to 99.26%)99.89% (99.55 to 100%)Determine–HBsAg98.24% (94.74 to 99.98%)99.96% (99.31 to 100%)98.76% (94.67 to 99.99%)99.94% (99.49 to 100%)Amrad–HBs+eAg95.47% (88.88 to 99.44%)99.81% (99.33 to 100%)98.04% (93.39 to 99.83%)99.95% (99.71 to 100%)Anti-HBs93.15% (85.04 to 98.5%)93.08% (81.9 to 99.99%)99.77% (94.18 to 100%)96.08% (86.38 to 100%)

Conclusion

The Amrad and Determine tests show the highest pooled accuracy. However, this could be explained by the fact that the other subgroups included studies examining different index tests with a wide range of accuracies. There is a need for more consistently designed studies, using ideal reference standards recommended by the CDC or Health Canada.