Clinical impact and cost analysis of the use of either the Xpert MTB Rif test or sputum smear microscopy in the diagnosis of pulmonary tuberculosis in Rio de Janeiro, Brazil

• Published in: Revista da Sociedade Brasileira de Medicina Tropical Vol. 51; no. 5; pp. 631 - 637
• Main Authors: Castro, Anália Zuleika de, Moreira, Adriana Rezende, Oliveira, Jaqueline, Costa, Paulo Albuquerque, Graça, Carolyne Lalucha Alves Lima Da, Pérez, Mauricio de Andrade, Kritski, Afrânio, Vater, Maria Claudia
• Format: Journal Article
• Language: English
• Published: Brazil Sociedade Brasileira de Medicina Tropical 01.09.2018; Sociedade Brasileira de Medicina Tropical - SBMT; Sociedade Brasileira de Medicina Tropical (SBMT)
• Subjects: Adult; Cost analysis; Costs; Costs and Cost Analysis; Diagnosis; Diagnostic methods; Diagnostic systems; Diagnostic Tests, Routine - economics; Female; Human resources; Humans; Impact analysis; Male; Medical diagnosis; Microscopy; Mycobacterium tuberculosis - isolation & purification; Predictive Value of Tests; Pulmonary tuberculosis; Sensitivity; Sensitivity and Specificity; Smear; Sputum; Sputum - microbiology; Sputum smear microscopy; Time lag; TROPICAL MEDICINE; Tuberculosis; Tuberculosis, Pulmonary - diagnosis; Xpert MTB/RIFtest; Brazil; United States > US; Rio de Janeiro Brazil; Sputum smear microscopy; Xpert MTB/RIFtest; Diagnostic methods; Cost analysis; Pulmonary tuberculosis
• ISSN: 0037-8682; 1678-9849; 1678-9849
• DOI: 10.1590/0037-8682-0082-2018

The molecular test Xpert MTB/RIF (Xpert) has been recommended for use in the diagnosis of pulmonary tuberculosis (PTB); however, data on the cost of incorporating it under routine conditions in high-burden countries are scarce. The clinical impact and costs incurred in adopting the Xpert test in routine PTB diagnosis was evaluated in a prospective study conducted from November 2012 to November of 2013, in the City of Rio de Janeiro, Brazil. The diagnostic and therapeutic cascade for TB treatment was evaluated using Xpert in the first stage (S1), and sputum smear microscopy (SSM) in the second stage (S2). The mean costs associated with each diagnostic test were calculated including equipment, human resources, supplies, and infrastructure. We included 232 subjects with probable TB (S1 = 87; S2 = 145). The sensitivities of Xpert and SSM were 91.7% (22/24) and 79.1% (34/43), respectively. The median time between triage and TB treatment initiation in S1 (n = 24) was 14.5 days (IQR 8-28.0) and in S2 (n = 43) it was 8 days [interquartile range (IQR) 6-12.0]. The estimated mean costs per examination in S1 and S2 were US$24.61 and US$6.98, respectively. Compared with SSM, Xpert test showed a greater sensitivity, but it also had a time delay with respect to treatment initiation and a higher mean cost per examination.