title: Bottom-up or top-down: unit cost estimation of tuberculosis diagnostic tests in India.
abstract: Of 18 sites that participated in an implementation study of the Xpert® MTB/RIF assay in India, we selected five microscopy centres and two reference laboratories.
  
  
  
  To obtain unit costs of diagnostic tests for tuberculosis (TB) and drug-resistant TB.
  
  
  
  Laboratories were purposely selected to capture regional variations and different laboratory types. Both bottom-up and the top-down methods were used to estimate unit costs.
  
  
  
  At the microscopy centres, mean bottom-up unit costs were respectively US$0.83 (range US$0.60-US$1.10) and US$12.29 (US$11.61-US$12.89) for sputum smear microscopy and Xpert. At the reference laboratories, mean unit costs were US$1.69 for the decontamination procedure, US$9.83 for a solid culture, US$11.06 for a liquid culture, US$29.88 for a drug susceptibility test, and US$18.18 for a line-probe assay. Top-down mean unit cost estimates were higher for all tests, and for sputum smear microscopy and Xpert these increased to respectively US$1.51 and US$13.58. The difference between bottom-up and top-down estimates was greatest for tests performed at the reference laboratories.
  
  
  
  These unit costs for TB diagnostics can be used to estimate resource requirements and cost-effectiveness in India, taking into account geographical location, laboratory type and capacity utilisation.
authors.affiliation: Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Rupert
authors.affiliation: Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands, Social and Mathematical Epidemiology Group, Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Vassall
authors.affiliation: Foundation for Innovative New Diagnostics, New Delhi.
authors.forename: N
authors.initials: N
authors.lastname: Raizada
authors.affiliation: Central TB Division, Government of India, New Delhi.
authors.forename: S D
authors.initials: SD
authors.lastname: Khaparde
authors.affiliation: Foundation for Innovative New Diagnostics, New Delhi.
authors.forename: C
authors.initials: C
authors.lastname: Boehme
authors.affiliation: Central TB Division, Ministry of Health and Family Welfare, New Delhi.
authors.forename: V S
authors.initials: VS
authors.lastname: Salhotra
authors.affiliation: Central TB Division, Government of India, New Delhi.
authors.forename: K S
authors.initials: KS
authors.lastname: Sachdeva
authors.affiliation: World Health Organization, Country Office for India, New Delhi, India.
authors.forename: S A
authors.initials: SA
authors.lastname: Nair
authors.affiliation: Academic Medical Centre, University of Amsterdam, Department of Global Health, Amsterdam, The Netherlands.
authors.forename: A H Van't
authors.initials: AH
authors.lastname: Hoog
mesh_terms: D003362:Cost-Benefit Analysis; D003365:Costs and Cost Analysis; D003955:Diagnostic Tests, Routine / Q000191:economics / Q000379:methods; D006801:Humans; D007194:India; D008853:Microscopy / Q000191:economics / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000191:economics / Q000379:methods*; D013183:Sputum / Q000382:microbiology; D014376:Tuberculosis / Q000175:diagnosis*; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis*