Microscopic observation drug-susceptibility assay vs. Xpert® MTB/RIF for the diagnosis of tuberculosis in a rural African setting: a cost-utility analysis

Trop Med Int Health. 2017 Jun;22(6):734-743. doi: 10.1111/tmi.12879. Epub 2017 May 2.

Abstract

Objective: To compare the cost-utility of microscopic observation drug-susceptibility assay (MODS) and Xpert® MTB/RIF implementation for tuberculosis (TB) diagnosis in rural northern Mozambique.

Methods: Stochastic transmission compartmental TB model from the healthcare provider perspective with parameter input from direct measurements, systematic literature reviews and expert opinion. MODS and Xpert® MTB/RIF were evaluated as replacement test of smear microscopy (SM) or as an add-on test after a negative SM. Costs were calculated in 2013 USD, effects in disability-adjusted life years (DALY). Willingness to pay threshold (WPT) was established at once the per capita Gross National Income of Mozambique.

Results: MODS as an add-on test to negative SM produced an incremental cost-effectiveness ratio (ICER) of 5647.89USD/DALY averted. MODS as a substitute for SM yielded an ICER of 5374.58USD/DALY averted. Xpert® MTB/RIF as an add-on test to negative SM yielded ICER of 345.71USD/DALY averted. Xpert® MTB/RIF as a substitute for SM obtained an ICER of 122.13USD/DALY averted. TB prevalence and risk of infection were the main factors impacting MODS and Xpert® MTB/RIF ICER in the one-way sensitivity analysis. In the probabilistic sensitivity analysis, Xpert® MTB/RIF was most likely to have an ICER below the WPT, whereas MODS was not.

Conclusion: Our cost-utility analysis favours the implementation of Xpert® MTB/RIF as a replacement of SM for all TB suspects in this rural high TB/HIV prevalence African setting.

Keywords: Mycobacterium tuberculosis; Afrique subsaharienne; Diagnóstico; Sub-Saharan Africa; analyse coût-efficacité; análisis de Coste-Efectividad; cost-effectiveness analysis; diagnosis; diagnostic; África subsahariana.

Publication types

  • Comparative Study

MeSH terms

  • Antibiotics, Antitubercular / pharmacology
  • Cost-Benefit Analysis*
  • Costs and Cost Analysis
  • DNA, Bacterial / analysis
  • Drug Resistance, Bacterial*
  • Humans
  • Microbial Sensitivity Tests / economics
  • Microscopy*
  • Molecular Diagnostic Techniques* / economics
  • Mozambique
  • Mycobacterium tuberculosis* / drug effects
  • Mycobacterium tuberculosis* / genetics
  • Mycobacterium tuberculosis* / growth & development
  • Prevalence
  • Quality-Adjusted Life Years
  • Rifampin / pharmacology*
  • Rural Population
  • Sensitivity and Specificity
  • Sputum
  • Tuberculosis, Multidrug-Resistant / diagnosis
  • Tuberculosis, Multidrug-Resistant / drug therapy
  • Tuberculosis, Multidrug-Resistant / microbiology
  • Tuberculosis, Pulmonary / diagnosis*
  • Tuberculosis, Pulmonary / drug therapy
  • Tuberculosis, Pulmonary / microbiology

Substances

  • Antibiotics, Antitubercular
  • DNA, Bacterial
  • Rifampin