Objective To examine access to routine viral load testing and causes of virological failure after 1 year of antiretroviral therapy (ART) among people with HIV. Additionally, to evaluate the positive predictive value (PPV) of immunological criteria to detect treatment failure.
Method A retrospective cohort of 3449 people with HIV who started ART between 1 January 2005 and 31 December 2009 in 13 outpatient clinics in Vietnam was studied. Cox hazard regression modelling was used to calculate crude and adjusted HRs and 95% CIs for associations between patient characteristics and virological failure.
Results Only 63% (2010/3199) of patients had access to routine viral load testing after 1 year of ART. After adjusting for other factors, patients with a baseline CD4 count of 50–100, 101–200 and 201–350 cells/mm3 were 0.48 (95% CI 0.20 to 0.74), 0.63 (95% CI 0.23 to 0.82) and 0.73 times (95% CI 0.14 to 0.95) as likely to have virological failure, respectively, as those with a baseline CD4 count <50 cells/mm3. After adjusting for other factors, patients with good treatment adherence were 0.54 times as likely to have viraemia as those with poor treatment adherence (95% CI 0.28 to 0.81) and patients with immunological failure were 1.43 times as likely to have viraemia (95% CI 1.31 to 1.65) as those without. The PPV of immunological criteria was 60.1% (95% CI 57.1% to 69.3%).
Conclusions Routine viral load tests should be conducted early to detect virological failure and prevent unnecessary changes to second-line treatments. To improve treatment outcomes, timely ART initiation and treatment adherence should be promoted.
- VIROLOGY HIV
- ANTERETROVIRAL THERAPY