A comparison of virological suppression and rebound between Indigenous and non-Indigenous persons initiating combination antiretroviral therapy in a multisite cohort of individuals living with HIV in Canada.

Background: This study compared time to virological suppression and rebound between Indigenous and non-Indigenous individuals living with HIV in Canada initiating combination antiretroviral therapy (cART). Methods: Data were from the Canadian Observational Cohort collaboration; eight studies of treatment-naive persons with HIV initiating cART after 1/1/2000. Fine and Gray models were used to estimate the effect of ethnicity on time to virological suppression (two consecutive viral loads [VLs] <50 copies/ml at least 3 months apart) after adjusting for the competing risk of death and time until virological rebound (two consecutive VLs >200 copies/ml at least 3 months apart) following suppression. Results: Among 7,080 participants were 497 Indigenous persons of whom 413 (83%) were from British Columbia. The cumulative incidence of suppression 1 year after cART initiation was 54% for Indigenous persons, 77% for Caucasian and 80% for African, Caribbean or Black (ACB) persons. The cumulative incidence of rebound 1 year after suppression was 13% for Indigenous persons, 6% for Caucasian and 7% for ACB persons. Indigenous persons were less likely to achieve suppression than Caucasian participants (aHR=0.58, 95% CI 0.50, 0.68), but not more likely to experience rebound (aHR=1.03, 95% CI 0.84, 1.27) after adjusting for age, gender, injection drug use, men having sex with men status, province of residence, baseline VL and CD4 + T-cell count, antiretroviral class and year of cART initiation. Conclusions: Lower suppression rates among Indigenous persons suggest a need for targeted interventions to improve HIV health outcomes during the first year of treatment when suppression is usually achieved.