title: A longitudinal analysis of healthcare costs after treatment optimization following genotypic antiretroviral resistance testing: does resistance testing pay off?
abstract: OBJECTIVE
  To assess the impact of antiretroviral therapy optimized by genotypic antiretroviral resistance testing (GRT) on healthcare costs over a 2-year period in patients after antiretroviral treatment failure.
  
  
  METHODS
  Non-randomized, prospective, tertiary care, clinic-based study.
  
  
  METHODS
  One-hundred and forty-two HIV patients enrolled in the 'ZIEL' study and the Swiss HIV Cohort Study who experienced virological treatment failure.
  
  
  METHODS
  For all patients GRT was used to optimize the antiretroviral treatment regimen. All healthcare costs during 2 years following GRT were assessed using microcosting. Costs were separated into ART medication costs and healthcare costs other than ART medication (that is, non-ART medication costs, in-patient costs and ambulatory [out-patient] costs). These cost estimates were then split into four consecutive 6-month periods (period 1-4) and the accumulated cost for each period was calculated. Univariate and multivariate regression modelling techniques for repeated measurements were applied to assess the changes of healthcare costs over time and factors associated with healthcare costs following GRT.
  
  
  RESULTS
  Overall healthcare costs after GRT decreased over time and were significantly higher in period 1 (32%; 95% confidence interval [Cl]: 18-47) compared with period 4. ART medication costs significantly increased by 1,017 (95% Cl: 22-2,014) Swiss francs (CHF) from period 1-4, whereas healthcare costs other than ART medication costs decreased substantially by a factor of 3.1 (95% Cl: 2.6-3.7) from period 1 to period 4. Factors mostly influencing healthcare costs following GRT were AIDS status, costs being 15% (95% Cl: 6-24) higher in patients with AIDS compared with patients without AIDS, and baseline viral load, costs being 12% (95% Cl: 6-17) higher in patients with each log increase in plasma RNA.
  
  
  CONCLUSIONS
  Optimized antiretroviral treatment regimens following GRT lead to a reduction of healthcare costs in patients with treatment failure over 2 years. Patients in a worse health state (that is, a positive AIDS status and high baseline viral load) will experience higher overall costs.
authors.affiliation: Division of Infectious Diseases, University Hospital Basel, Basel, Switzerland.
authors.forename: Mathew
authors.initials: M
authors.lastname: Simcock
authors.forename: Pedram
authors.initials: P
authors.lastname: Sendi
authors.forename: Bruno
authors.initials: B
authors.lastname: Ledergerber
authors.forename: Tamara
authors.initials: T
authors.lastname: Keller
authors.forename: Jörg
authors.initials: J
authors.lastname: Schüpbach
authors.forename: Manuel
authors.initials: M
authors.lastname: Battegay
authors.forename: Huldrych F
authors.initials: HF
authors.lastname: Günthard
mesh_terms: D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000191:economics / Q000494:pharmacology* / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D003362:Cost-Benefit Analysis; D024882:Drug Resistance, Viral / Q000235:genetics*; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics; D017048:Health Care Costs; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D015999:Multivariate Analysis; D013997:Time Factors; D017211:Treatment Failure
chemical_list: D019380:Anti-HIV Agents