Xpert TB diagnostic highlights gap in point-of-care pipeline.

The Lancet Infectious Diseases (Impact Factor: 19.45). 11/2010; 10(11):742-3. DOI: 10.1016/S1473-3099(10)70231-0
Source: PubMed
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    ABSTRACT: Point of care (POC) diagnostics are often hailed as having the potential to transform tuberculosis (TB) control efforts. However, POC testing is better conceptualized as a system of diagnosis and treatment, not simply a test that can provide rapid, deployable results. Economic evaluations may help decision makers allocate scarce resources for TB control, but evaluations of POC testing face unique challenges that include evaluating the full diagnostic system, incorporating implementation costs, translating diagnostic results into health and accounting for downstream treatment costs. For economic evaluations to reach their full potential as decision-making tools for POC testing in TB, these challenges must be understood and addressed.
    Expert Review of Pharmacoeconomics & Outcomes Research 06/2013; 13(3):313-25. DOI:10.1586/erp.13.27 · 1.87 Impact Factor
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    ABSTRACT: Objective The World Health Organization recommends using Xpert MTB/RIF for diagnosis of pulmonary tuberculosis (PTB), but there is little evidence on the optimal placement of Xpert instruments in public health systems. We used recent South African data to compare the cost of placing Xpert at points of TB treatment (all primary clinics and hospitals) with the cost of placement at sub-district laboratories. Methods We estimated Xpert’s cost/test in a primary clinic pilot and in the pilot phase of the national Xpert roll-out to smear microscopy laboratories; the expected future volumes for each of 223 laboratories or 3799 points of treatment; the number and cost of Xpert instruments required and the national cost of using Xpert for PTB diagnosis for each placement scenario in 2014. Results In 2014, South Africa will test 2.6 million TB suspects. Laboratory placement requires 274 Xpert instruments, while point-of-treatment placement requires 4020 instruments. With an Xpert cartridge price of $14.00, the cost/test is $26.54 for laboratory placement and $38.91 for point-of-treatment placement. Low test volumes and a high number of sites are the major contributors to higher point-of-treatment costs. National placement of Xpert at laboratories would cost $71 million/year; point-of-treatment placement would cost $107 million/year, 51% more. Conclusion Placing Xpert technology at points of treatment is substantially more expensive than placing the instruments in smear microscopy laboratories. The incremental benefits of point-of-treatment placement, in terms of better patient outcomes, will have to be equally substantial to justify the additional cost to the national health budget.
    Tropical Medicine & International Health 06/2012; 17(9):1142-51. DOI:10.1111/j.1365-3156.2012.03028.x · 2.30 Impact Factor
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    ABSTRACT: Setting:We conducted a retrospective study among HIV-infected adult suspects (18 years) with pulmonary tuberculosis (TB), who underwent Xpert MTB/RIF (Xpert) testing at McCord Hospital and its adjoining HIV clinic in Durban, South Africa.Objective:To determine if Xpert testing performed at a centralized laboratory accelerated time to TB diagnosis.Design:We obtained data on sputum smear microscopy [acid-fast bacilli (AFB)], Xpert, and the rationale for treatment initiation from medical records. The primary outcome was total diagnostic time, defined as time from sputum collection to clinicians' receipt of results. A linear mixed-effect model compared the duration of steps in the diagnostic pathway across testing modalities.Results:Among 403 participants, the median total diagnostic time for AFB and Xpert was 3.3 and 6.4 days, respectively (P < 0.001). When compared with AFB, the median delay for Xpert laboratory processing was 1.4 days (P < 0.001) and result transfer to clinic was 1.7 days (P < 0.001). Among 86 Xpert-positive participants who initiated treatment, 49 (57%) started treatment based on clinical suspicion or AFB-positive results, whereas only 32 (37%) started treatment based on Xpert-positive results.Conclusions:In our setting, Xpert results took twice as long as AFB results to reach clinicians. Replacing AFB with centralized Xpert may delay TB diagnoses in some settings.
    JAIDS Journal of Acquired Immune Deficiency Syndromes 11/2014; 67(3):e88-e93. DOI:10.1097/QAI.0000000000000309 · 4.39 Impact Factor