Cost analysis of smear microscopy and the Xpert assay for tuberculosis diagnosis: average turnaround time

Abstract INTRODUCTION: Rapid and accurate tuberculosis detection is critical for improving patient diagnosis and decreasing tuberculosis transmission. Molecular assays can significantly increase laboratory costs; therefore, the average time and economic impact should be evaluated before implementing a new technology. The aim of this study was to evaluate the cost and average turnaround time of smear microscopy and Xpert assay at a university hospital. METHODS: The turnaround time and cost of the laboratory diagnosis of tuberculosis were calculated based on the mean cost and activity based costing (ABC). RESULTS: The average turnaround time for smear microscopy was 16.6 hours while that for Xpert was 24.1 hours. The Xpert had a mean cost of USD 17.37 with an ABC of USD 10.86, while smear microscopy had a mean cost of USD 13.31 with an ABC of USD 6.01. The sensitivity of smear microscopy was 42.9% and its specificity was 99.1%, while the Xpert assay had a sensitivity of 100% and a specificity of 96.7%. CONCLUSIONS: The Xpert assay has high accuracy; however, the turnaround time and cost of smear microscopy were lower than those of Xpert.

A novel tissue microarray instrumentation:The HT-1 tissue microarrayer.

Background: Tissue microarray (TMA) is a novel and useful tool to efficiently analyze gene expression in histological tissues. Aim: Cost-efficient and easy to use automated tissue arrayers will provide a better instrumentation to generate TMAs. Thus, we designed and produced our tissue microarrayer to meet these needs. Materials and Methods: The HT-1 tissue microarrayer we designed and manufactured consists primarily of four parts, including an instrument to make array pores for the recipient paraffin blocks, a punch needle, an instrument for negative-pressure embedding, and a special manipulator. By using the HT-1, 14 different TMAs were made to accommodate 312 cases of tissues and TMA sections were tested by hematoxylin-eosin (H&E) staining, in situ hybridization, and immunohistochemistry. Results: Expand: Hematoxylin and eosin staining showed that the tissue cylinders were similar, even, and in order on the slides. Most importantly, the HT-1 microarrayer can make array pores in the recipient paraffin block with a single application in seconds. The HT-1 also contains a unique negative pressure system for embedding TMA blocks. In addition, HT-1 can make tissue cylinders with the same levels and depth for equally embedded and sectioning. Conclusions: The HT-1 tissue microarrayer is a device that is simple, economical and easy to use.