title: Rates and factors associated with major modifications to first-line combination antiretroviral therapy: results from the Asia-Pacific region.
abstract: BACKGROUND
  In the Asia-Pacific region many countries have adopted the WHO's public health approach to HIV care and treatment. We performed exploratory analyses of the factors associated with first major modification to first-line combination antiretroviral therapy (ART) in resource-rich and resource-limited countries in the region.
  
  
  METHODS
  We selected treatment naive HIV-positive adults from the Australian HIV Observational Database (AHOD) and the TREAT Asia HIV Observational Database (TAHOD). We dichotomised each country's per capita income into high/upper-middle (T-H) and lower-middle/low (T-L). Survival methods stratified by income were used to explore time to first major modification of first-line ART and associated factors. We defined a treatment modification as either initiation of a new class of antiretroviral (ARV) or a substitution of two or more ARV agents from within the same ARV class.
  
  
  RESULTS
  A total of 4250 patients had 961 major modifications to first-line ART in the first five years of therapy. The cumulative incidence (95% CI) of treatment modification was 0.48 (0.44-0.52), 0.33 (0.30-0.36) and 0.21 (0.18-0.23) for AHOD, T-H and T-L respectively. We found no strong associations between typical patient characteristic factors and rates of treatment modification. In AHOD, relative to sites that monitor twice-yearly (both CD4 and HIV RNA-VL), quarterly monitoring corresponded with a doubling of the rate of treatment modifications. In T-H, relative to sites that monitor once-yearly (both CD4 and HIV RNA-VL), monitoring twice-yearly corresponded to a 1.8 factor increase in treatment modifications. In T-L, no sites on average monitored both CD4 & HIV RNA-VL concurrently once-yearly. We found no differences in rates of modifications for once- or twice-yearly CD4 count monitoring.
  
  
  CONCLUSIONS
  Low-income countries tended to have lower rates of major modifications made to first-line ART compared to higher-income countries. In higher-income countries, an increased rate of RNA-VL monitoring was associated with increased modifications to first-line ART.
authors.affiliation: Kirby Institute, Sydney, Australia. swright@kirby.unsw.edu.au
authors.forename: Stephen
authors.initials: S
authors.lastname: Wright
authors.forename: Mark A
authors.initials: MA
authors.lastname: Boyd
authors.forename: Evy
authors.initials: E
authors.lastname: Yunihastuti
authors.forename: Matthew
authors.initials: M
authors.lastname: Law
authors.forename: Thira
authors.initials: T
authors.lastname: Sirisanthana
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hoy
authors.forename: Sanjay
authors.initials: S
authors.lastname: Pujari
authors.forename: Man Po
authors.initials: MP
authors.lastname: Lee
authors.forename: Kathy
authors.initials: K
authors.lastname: Petoumenos
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000191:economics / Q000627:therapeutic use*; D001208:Asia / Q000453:epidemiology; D001315:Australia / Q000453:epidemiology; D003906:Developing Countries; D057915:Drug Substitution / Q000191:economics / Q000706:statistics & numerical data; D004359:Drug Therapy, Combination / Q000191:economics / Q000706:statistics & numerical data; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology; D017048:Health Care Costs; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012959:Socioeconomic Factors; D016896:Treatment Outcome
chemical_list: D019380:Anti-HIV Agents