title: Cost-effectiveness of HIV drug resistance testing to inform switching to second line antiretroviral therapy in low income settings.
abstract: BACKGROUND
  To guide future need for cheap resistance tests for use in low income settings, we assessed cost-effectiveness of drug resistance testing as part of monitoring of people on first line ART - with switching from first to second line ART being conditional on NNRTI drug resistance mutations being identified.
  
  
  METHODS
  An individual level simulation model of HIV transmission, progression and the effect of ART which accounts for adherence and resistance development was used to compare outcomes of various potential monitoring strategies in a typical low income setting in sub-Saharan Africa. Underlying monitoring strategies considered were based on clinical disease, CD4 count or viral load. Within each we considered a strategy in which no further measures are performed, one with a viral load measure to confirm failure, and one with both a viral load measure and a resistance test. Predicted outcomes were assessed over 2015-2025 in terms of viral suppression, first line failure, switching to second line regimen, death, HIV incidence, disability-adjusted-life-years averted and costs. Potential future low costs of resistance tests ($30) were used.
  
  
  RESULTS
  The most effective strategy, in terms of DALYs averted, was one using viral load monitoring without confirmation. The incremental cost-effectiveness ratio for this strategy was $2113 (the same as that for viral load monitoring with confirmation). ART monitoring strategies which involved resistance testing did not emerge as being more effective or cost effective than strategies not using it. The slightly reduced ART costs resulting from use of resistance testing, due to less use of second line regimens, was of similar magnitude to the costs of resistance tests.
  
  
  CONCLUSIONS
  Use of resistance testing at the time of first line failure as part of the decision whether to switch to second line therapy was not cost-effective, even though the test was assumed to be very inexpensive.
authors.affiliation: Research Department of Infection & Population Health, UCL, London, United Kingdom.
authors.forename: Andrew
authors.initials: A
authors.lastname: Phillips
authors.affiliation: Research Department of Infection & Population Health, UCL, London, United Kingdom.
authors.forename: Valentina
authors.initials: V
authors.lastname: Cambiano
authors.affiliation: Research Department of Infection & Population Health, UCL, London, United Kingdom.
authors.forename: Fumiyo
authors.initials: F
authors.lastname: Nakagawa
authors.forename: Travor
authors.initials: T
authors.lastname: Mabugu
authors.affiliation: University of Zimbabwe Clinical Research Centre, Harare, Zimbabwe.
authors.forename: Travor
authors.initials: T
authors.lastname: Magubu
authors.affiliation: Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Alec
authors.initials: A
authors.lastname: Miners
authors.affiliation: MRC Clinical Trials Unit, UCL, London, United Kingdom.
authors.forename: Debbie
authors.initials: D
authors.lastname: Ford
authors.affiliation: Africa Centre, KwaZulu Natal, South Africa.
authors.forename: Deenan
authors.initials: D
authors.lastname: Pillay
authors.affiliation: University Division of Infectious Diseases, Siena University Hospital, Siena, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: De Luca
authors.affiliation: Dept of Infectious Diseases, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Lundgren
authors.affiliation: Centre for Health Economics, University of York, York, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Revill
mesh_terms: D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000494:pharmacology / Q000627:therapeutic use; D003362:Cost-Benefit Analysis; D024882:Drug Resistance, Viral / Q000235:genetics; D057915:Drug Substitution; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics; D006801:Humans; D015994:Incidence; D008826:Microbial Sensitivity Tests / Q000191:economics*; D008875:Middle Aged; D011203:Poverty; D015995:Prevalence; D017211:Treatment Failure; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents