Determinants of loss to follow-up in patients on antiretroviral treatment, South Africa, 2004–2012: a cohort study (BMC Health Services Research)

Background: The number of Human Immunodeficiency Virus (HIV) infected people eligible for initiation on antiretroviral Therapy (ART) is increasing. ART programmatic success requires that patients who are taking ART remain on treatment and are followed up regularly. This study investigated factors associated with being lost to follow-up, in a cohort of patients enrolled in a pharmacovigilance study in South Africa. Methods: This was a retrospective observational cohort study performed at one of the Medunsa National Pharmacovigilance Centre’s (MNPC) ART sentinel surveillance sites. Loss to Follow-up (LTFU) was defined as “a patient who had been followed up at the sentinel site, who had not had contact with the health facility for 180 days or more since their last recorded expected date of return or if there were 180 days or more between the expected date of return and the next clinic visit”. Results: Out of 595 patients, 65.5 % (n = 390) were female and 23.4 % (n = 139) were LTFU. The median time on ART before LTFU was 21.5 months (interquartile range: 12.9 – 34.7 months). The incidence rate of LTFU was 103 per 1000 person-years in the first year on ART and increased to 405 per 1000 person-years in the eighth year of taking ART. Factors associated with becoming LTFU included not having a committed partner (Adjusted Hazard Ratio (aHR): 2.9, 95 % Confidence Interval (CI):1.19-6.97, p = 0.019), being self-employed (aHR: 13.9, 95 % CI:2.81 - 69.06, p = 0.001), baseline CD4 count > 200 cells/ml (aHR: 3.8, 95 % CI: 1.85-7.85, p