Abstract
Background Despite the introduction of eff ective antiretroviral therapy (ART), HIV remains one of the most important
communicable diseases and a key public health issue in European countries. Epidemiological data are important
to form a detailed picture of the HIV epidemic over time to help inform policies and decision-making processes and
allow future projections. The aim was to develop an approach to fi t a comprehensive model of HIV progression
and the eff ect of ART to surveillance and observational cohort data from European countries, to estimate and
characterise the status of HIV-positive populations. We present a pilot of this approach using data for men who have
sex with men (MSM) in the UK.