Do adjunct tuberculosis tests, when combined with Xpert MTB/RIF, improve accuracy and the cost of diagnosis in a resource-poor setting?
| Autor: | Richard N. van Zyl-Smit, Grant Theron, Richard Meldau, Brian Allwood, Jonny Peter, Anil Pooran, Rod Dawson, Keertan Dheda, Greg Calligaro, Surendra K. Sharma, Hridesh Mishra |
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| Rok vydání: | 2011 |
| Předmět: |
Pulmonary and Respiratory Medicine
medicine.medical_specialty Tuberculosis HIV Infections Context (language use) Sensitivity and Specificity Article Smear microscopy South Africa 03 medical and health sciences 0302 clinical medicine Tuberculosis diagnosis Predictive Value of Tests Internal medicine Active tb polycyclic compounds medicine Humans 030212 general & internal medicine Resource poor Tuberculin Test business.industry Sputum Mycobacterium tuberculosis biochemical phenomena metabolism and nutrition bacterial infections and mycoses medicine.disease Predictive value 3. Good health Surgery Radiography 030220 oncology & carcinogenesis Predictive value of tests Costs and Cost Analysis Health Resources Rifampin business Interferon-gamma Release Tests |
| Zdroj: | European Respiratory Journal. 40:161-168 |
| ISSN: | 1399-3003 0903-1936 |
| DOI: | 10.1183/09031936.00145511 |
| Popis: | Information regarding the utility of adjunct diagnostic tests in combination with Xpert MTB/RIF (Cepheid, Sunnyvale, CA, USA) is limited. We hypothesised adjunct tests could enhance accuracy and/or reduce the cost of tuberculosis (TB) diagnosis prior to MTB/RIF testing, and rule-in or rule-out TB in MTB/RIF-negative individuals. We assessed the accuracy and/or laboratory-associated cost of diagnosis of smear microscopy, chest radiography (CXR) and interferon-γ release assays (IGRAs; T-SPOT-TB (Oxford Immunotec, Oxford, UK) and QuantiFERON-TB Gold In-Tube (Cellestis, Chadstone, Australia)) combined with MTB/RIF for TB in 480 patients in South Africa. When conducted prior to MTB/RIF: 1) smear microscopy followed by MTB/RIF (if smear negative) had the lowest cost of diagnosis of any strategy investigated; 2) a combination of smear microscopy, CXR (if smear negative) and MTB/RIF (if imaging compatible with active TB) did not further reduce the cost per TB case diagnosed; and 3) a normal CXR ruled out TB in 18% of patients (57 out of 324; negative predictive value (NPV) 100%). When downstream adjunct tests were applied to MTB/RIF-negative individuals, radiology ruled out TB in 24% (56 out of 234; NPV 100%), smear microscopy ruled in TB in 21% (seven out of 24) of culture-positive individuals and IGRAs were not useful in either context. In resource-poor settings, smear microscopy combined with MTB/RIF had the highest accuracy and lowest cost of diagnosis compared to either technique alone. In MTB/RIF-negative individuals, CXR has poor rule-in value but can reliably rule out TB in approximately one in four cases. These data inform upon the programmatic utility of MTB/RIF in high-burden settings. |
| Databáze: | OpenAIRE |
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