Incidence and risk factors associated with lost to follow-up in a Belgian cohort of HIV-infected patients treated with highly active antiretroviral therapy.

Being lost to follow-up (LTFU) is a major problem in caring for persons with HIV infection. We describe the proportions and characteristics of LTFU in a Belgian outpatient HIV clinic. All patients treated with highly active antiretroviral therapy (HAART) who attended at least two consultations were included. Patients not returning within the following year were considered LTFU. Multivariate analysis using logistic regression was performed. The LTFU rate was 5.5% on average and remained stable over the years. Patients LTFU were more often intravenous drug users (odds ratio [OR] = 3.48), not covered by health insurance (OR = 6.69), living outside the province (OR = 1.49) and treated with a complex initial HAART regimen (OR = 5.80). Increased age was also associated with a higher risk of LTFU. Patients at risk for LTFU after starting HAART should be the targeted for reinforced counselling and HIV treatment centres should establish systems to trace patients LTFU.