Of the 35,428 people receiving care in England, Wales and Northern Ireland in 2003, 23,298 (66%) were using some form of antiretroviral therapy (mono-, dual, triple or quadruple therapy).

In total 15,557 patients were taking triple combination therapy. This represents 52% of all people being seen for HIV-related care. As expected, a much smaller proportion (360 individuals or 1% of all people being seen for care) were taking dual therapy. A total of 3472 individuals were taking four or more anti-HIV drugs, 10% of all patients receiving HIV-related care.

Outside of London and the South East, where 15,398 individuals or 66% of all people on treatment reside, the regions with the biggest number of people on therapy are, in descending order, the North West (1892 individuals), the Eastern region (1250 individuals), the West Midlands (1033 individuals), the South West (902 individuals), Yorkshire and Humberside (890 individuals) and the East Midlands (844).

In 2001 there were 392 people resident in Wales who were taking anti-HIV therapy. A total of 122 people resident in Northern Ireland in 2003 were taking anti-HIV therapy.