Five-year trends in antiretroviral usage and drug costs in HIV-infected children in Thailand.
BACKGROUND
As antiretroviral treatment (ART) programs mature, data on drug utilization and costs are needed to assess durability of treatments and inform program planning.


METHODS
Children initiating ART were followed up in an observational cohort in Thailand. Treatment histories from 1999 to 2009 were reviewed. Treatment changes were categorized as: drug substitution (within class), switch across drug class (non nucleoside reverse-transcriptase inhibitors (NNRTI) to/from protease inhibitor (PI)), and to salvage therapy (dual PI or PI and NNRTI). Antiretroviral drug costs were calculated in 6-month cycles (US$ 2009 prices). Predictors of high drug cost including characteristics at start of ART (baseline), initial regimen, treatment change, and duration on ART were assessed using mixed-effects regression models.


RESULTS
Five hundred seven children initiated ART with a median 54 (interquartile range, 36-72) months of follow-up. Fifty-two percent had a drug substitution, 21% switched across class, and 2% to salvage therapy. When allowing for drug substitution, 78% remained on their initial regimen. Mean drug cost increased from $251 to $428 per child per year in the first and fifth year of therapy, respectively. PI-based and salvage regimens accounted for 16% and 2% of treatments prescribed and 33% and 5% of total costs, respectively. Predictors of high cost include baseline age ≥ 8 years, non nevirapine-based initial regimen, switch across drug class, and to salvage regimen (P < 0.005).


CONCLUSIONS
At 5 years, 21% of children switched across drug class and 2% received salvage therapy. The mean drug cost increased by 70%. Access to affordable second- and third-line drugs is essential for the sustainability of treatment programs.
Program for HIV Prevention and Treatment, Institut de Recherche pour le Développement IRD UMI 174-PHPT, France. intira.collins@lshtm.ac.uk
Intira
I
Collins
John
J
Cairns
Sophie
S
Le Coeur
Karin
K
Pagdi
Chaiwat
C
Ngampiyaskul
Prapaisri
P
Layangool
Thitiporn
T
Borkird
Sathaporn
S
Na-Rajsima
Vanichaya
V
Wanchaitanawong
Gonzague
G
Jourdain
Marc
M
Lallemant
D019380:Anti-HIV Agents / Q000191:economics* / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D002648:Child; D002675:Child, Preschool; D016527:Drug Costs / Q000706:statistics & numerical data / Q000639:trends*; D024882:Drug Resistance, Viral; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000191:economics* / Q000517:prevention & control; D006801:Humans; D008297:Male; D015397:Program Evaluation; D013785:Thailand / Q000453:epidemiology; D016896:Treatment Outcome; D019562:Viral Load
D019380:Anti-HIV Agents