Objective: To estimate time from HIV infection to linkage-to-care and its determinants.
Linkage-to-care is usually assessed using the date of HIV diagnosis as the starting
point for exposure time. However, timing of diagnosis is likely endogenous to linkage,
leading to bias in linkage estimation.
Design: We used longitudinal serosurveys from a large population-based HIV cohort in
KwaZulu-Natal (2004-2013) to estimate time of HIV infection. We linked this data to
patient records from a public-sector HIV treatment and care program to determine time
from infection to linkage (defined using the date of the first CD4 count).
Methods: We used Cox proportional-hazards models to estimate time from infection to
linkage and the effects of the following covariates on this time: gender, age, education,
food security, socio-economic status, area of residence, distance to clinics, knowledge
of HIV status, and whether other household members have initiated ART.
Results: We estimated that it would take an average of 4.9 years for 50% of
seroconverters to be linked to care (95% confidence intervals (CI): 4.2-5.7). Among all
cohort members that were linked to care, the median CD4 count at linkage was 350
cells/μL (95%CI: 330-380). Men and participants <30 years were found to have the
slowest rates of linkage-to-care. Time to linkage became shorter over calendar time.
Conclusions: Average time from HIV infection to linkage-to-care is long and needs to
be reduced to ensure that HIV treatment-as-prevention policies are effective. Targeted
interventions for men and young individuals have the largest potential to improve linkage rates