title: Cost-effectiveness of population-level expansion of highly active antiretroviral treatment for HIV in British Columbia, Canada: a modelling study.
abstract: BACKGROUND
  Widespread HIV screening and access to highly active antiretroviral treatment (ART) were cost effective in mathematical models, but population-level implementation has led to questions about cost, value, and feasibility. In 1996, British Columbia, Canada, introduced universal coverage of drug and other health-care costs for people with HIV/AIDS and and began extensive scale-up in access to ART. We aimed to assess the cost-effectiveness of ART scale-up in British Columbia compared with hypothetical scenarios of constrained treatment access.
  
  
  METHODS
  Using comprehensive linked population-level data, we populated a dynamic, compartmental transmission model to simulate the HIV/AIDS epidemic in British Columbia from 1997 to 2010. We estimated HIV incidence, prevalence, mortality, costs (in 2010 CAN$), and quality-adjusted life-years (QALYs) for the study period, which was 1997-2010. We calculated incremental cost-effectiveness ratios from societal and third-party-payer perspectives to compare actual practice (true numbers of individuals accessing ART) to scenarios of constrained expansion (75% and 50% probability of accessing ART). We also investigated structural and parameter uncertainty.
  
  
  RESULTS
  Actual practice resulted in 263 averted incident cases compared with 75% of observed access and 676 averted cases compared with 50% of observed access to ART. From a third-party-payer perspective, actual practice resulted in incremental cost-effectiveness ratios of $23 679 per QALY versus 75% access and $24 250 per QALY versus 50% access. From a societal perspective, actual practice was cost saving within the study period. When the model was extended to 2035, current observed access resulted in cumulative savings of $25·1 million compared with the 75% access scenario and $65·5 million compared with the 50% access scenario.
  
  
  CONCLUSIONS
  ART scale-up in British Columbia has decreased HIV-related morbidity, mortality, and transmission. Resulting incremental cost-effectiveness ratios for actual practice, derived within a limited timeframe, were within established cost-effectiveness thresholds and were cost saving from a societal perspective.
  
  
  BACKGROUND
  BC Ministry of Health, National Institute of Drug Abuse at the US National Institutes of Health.
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada; Faculty of Health Sciences, Simon Fraser University, Vancouver, BC, Canada.
authors.forename: Bohdan
authors.initials: B
authors.lastname: Nosyk
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
authors.forename: Jeong E
authors.initials: JE
authors.lastname: Min
authors.affiliation: Division of AIDS, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Viviane D
authors.initials: VD
authors.lastname: Lima
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada; Faculty of Health Sciences, Simon Fraser University, Vancouver, BC, Canada.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Hogg
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada; Division of AIDS, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada. Electronic address: jmontaner@cfenet.ubc.ca.
authors.forename: Julio S G
authors.initials: JS
authors.lastname: Montaner
mesh_terms: D000328:Adult; D023241:Antiretroviral Therapy, Highly Active / Q000191:economics*; D001955:British Columbia / Q000453:epidemiology; D018791:CD4 Lymphocyte Count / Q000191:economics; D003362:Cost-Benefit Analysis; D005240:Feasibility Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000191:economics* / Q000453:epidemiology; D017048:Health Care Costs; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D015995:Prevalence; D019057:Quality-Adjusted Life Years; D016896:Treatment Outcome