Effect of gender and calendar year on time to and duration of virologic suppression among antiretroviral-naïve HIV-infected individuals initiating combination antiretroviral therapy.
OBJECTIVE
To determine the effects of gender and calendar year on time to and duration of virologic suppression among HIV-infected antiretroviral-naïve individuals initiating combination antiretroviral therapy (cART).


METHODS
Ontario Cohort Study antiretroviral-naïve participants who initiated cART after December 31, 1998, and who had ≥2 follow-up viral loads were included. Multivariable Cox proportional hazard models were used to estimate the effects of gender and calendar year on times to virologic suppression and rebound.


RESULTS
Of the 840 patients, 81% were male (median age 40 years; interquartile range [IQR], 34-46). Time to virologic suppression was shorter among women (hazard ratio [HR]=1.27, P=.01) and in more recent calendar time periods (2002-2004: HR, 1.04, P=.67; 2005-2006: HR, 1.22, P=.06; 2007-2008: HR, 1.36, P=.004) compared to 1999-2001 after adjusting for age and type of cART regimens. Women had shorter times to virologic rebound (HR, 1.57; P<.01) after adjusting for age, injection drug use, and type of cART regimen. However, 14/18 (78%) women suspected to be taking cART only for prevention of mother-to-child transmission of HIV experienced virologic rebound compared to 28% of women who required cART for their own health, suggesting that the increased rate of virologic rebound was due to women stopping ART at the termination of a pregnancy if they did not need it for their own health. Rates of rebound did not differ by calendar year period.


CONCLUSIONS
Time to virologic suppression has steadily decreased over time while duration of suppression remained stable. Time to virologic suppression was shorter for women than for men, whereas durability of virologic suppression was slightly longer for men than women. However, gender differences in virologic rebound were likely due to women discontinuing cART at the end of the pregnancy if it was not needed for their own health.
University Health Network, Toronto, Ontario, Canada. raboud@lunenfeld.ca
Janet
J
Raboud
Sandra
S
Blitz
Sharon
S
Walmsley
Courtney
C
Thompson
Sean B
SB
Rourke
Mona R
MR
Loutfy
D000328:Adult; D044966:Anti-Retroviral Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015331:Cohort Studies; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009864:Ontario; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy / Q000821:virology; D016016:Proportional Hazards Models; D012307:Risk Factors; D012621:Seasons; D012737:Sex Factors; D013997:Time Factors; D019562:Viral Load / Q000187:drug effects*
D044966:Anti-Retroviral Agents