BACKGROUND: Understanding retention and loss to follow up in HIV care, in particular the number of people with unknown outcomes, is critical to maximise the benefits of antiretroviral therapy. Individual-level data are not available for these outcomes in Australia, which has an HIV epidemic predominantly focused amongst men who have sex with men. METHODS AND FINDINGS: A network of the 6 main HIV clinical care sites was established in the state of Victoria, Australia. Individuals who had accessed care at these sites between February 2011 and June 2013 as assessed by HIV viral load testing but not accessed care between June 2013 and February 2014 were considered individuals with potentially unknown outcomes. For this group an intervention combining cross-referencing of clinical data between sites and phone tracing individuals with unknown outcomes was performed. 4966 people were in care in the network and before the intervention estimates of retention ranged from 85.9%-95.8% and the proportion with unknown outcomes ranged from 1.3-5.5%. After the intervention retention increased to 91.4-98.8% and unknown outcomes decreased to 0.1-2.4% (p
McMahon, J. H.
, Moore, R., Eu, B., Tee, B. K., Chen, M. Y., El-Hayek, C., ... Hoy, J. F.
(2015). Clinic network collaboration and patient tracing to maximize retention in HIV care
. PLoS ONE
(5), 1 - 11. [e0127726]. https://doi.org/10.1371/journal.pone.0127726