title: Economics of switching to second-line antiretroviral therapy with lopinavir/ritonavir in Africa: estimates based on DART trial results and costs for Uganda and Kenya.
abstract: BACKGROUND
  Substantial immunological improvement has been reported for HIV-infected patients who switch from a failing regimen to a protease inhibitor regimen with Lopinavir/ritonavir (LPV/r). We use decision analysis modeling to estimate health and economic consequences expected from this switch.
  
  
  METHODS
  A Markov model combined best evidence for CD4(+) T-cell response, infectious disease events, death rates, and quality of life for African populations with Kenyan and Ugandan data on drug and medical care costs. We estimate the incremental cost-effectiveness ratio of switching to an LPV/r-based regimen versus remaining on a failed first antiretroviral (ARV) regimen or discontinuing all ARV drugs. The model assumes concurrent use of cotrimoxazole, and 4% annual loss to follow-up. Local effects due to prevalence of malaria and tuberculosis are included in the model. Sensitivity analysis examines the effects of varying disease, ARV therapy and CD4(+) T-cell cost, and ART discontinuation assumptions.
  
  
  RESULTS
  The base model estimates an improvement of 20 months in average survival for the LPV/r group. The respective LPV/r ICER for Kenya is $1483 per quality-adjusted life year (QALY) compared to $1673/QALY for Uganda. The ICERs increase to $1517 and $1707, respectively, if CD4(+) T-cell tests cost $25. The model comparing switching to LPV/r to discontinuing all ARV drugs decreases both costs and benefits proportionally for the treatment groups.
  
  
  CONCLUSIONS
  The estimates are clearly below the most stringent World Health Organization benchmark for cost-effectiveness for Kenya and within the acceptable range of cost-effectiveness for Uganda. Thus, the switch to second-line therapy with LPV/r in these countries appears to be a cost-effective use of resources.
authors.affiliation: Department of Health Leadership and Management, Medical University of South Carolina, Charleston, SC 29425, USA. simpsonk@musc.edu
authors.forename: Kit N
authors.initials: KN
authors.lastname: Simpson
authors.forename: Robert W
authors.initials: RW
authors.lastname: Baran
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Kirbach
authors.forename: Birgitta
authors.initials: B
authors.lastname: Dietz
mesh_terms: D019380:Anti-HIV Agents / Q000191:economics / Q000627:therapeutic use*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D004338:Drug Combinations; D016527:Drug Costs; D015658:HIV Infections / Q000188:drug therapy* / Q000191:economics; D017048:Health Care Costs; D006801:Humans; D007630:Kenya; D061466:Lopinavir / Q000191:economics / Q000627:therapeutic use*; D008390:Markov Chains; D018803:Models, Economic; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D019438:Ritonavir / Q000191:economics / Q000627:therapeutic use*; D014454:Uganda
chemical_list: D019380:Anti-HIV Agents; D004338:Drug Combinations; C558899:lopinavir-ritonavir drug combination; D061466:Lopinavir; D019438:Ritonavir