OBJECTIVES: The clinical and public health benefits of immediate antiretroviral treatment upon HIV-1 diagnosis have been demonstrated, and treatment guidelines have been updated accordingly. This analysis examines the health outcomes and cost-effectiveness associated with increased HIV-1 screening and immediate treatment initiation in the UK.
METHODS: A Markov model with a 3-month cycle length followed theoretical cohorts of men who have sex with men (MSM), heterosexuals, and injection drug users (IDUs) with initially undiagnosed HIV-1 infection over their remaining lifetimes. The model examined increased HIV-1 screening (resulting in a 30% improvement in annual diagnosis rates) compared with current screening. Health status was modeled with three HIV‑1 RNA viral load ranges and six health states defined by CD4 cell-count ranges as individuals progressed to diagnosis and treatment. Individuals accrued quality-adjusted life-years (QALYs), incurred costs for screening and for HIV-related clinical management, and were at risk of transmitting HIV-1 infection to their partners. Input parameter data were taken primarily from UK-specific published sources. All outcomes were estimated as per-person averages and were discounted at 3.5% annually.
RESULTS: The model estimated that increased HIV-1 screening followed by immediate treatment initiation resulted in an average of 0.3-0.5 fewer years spent undiagnosed (25-50% reduction), 0.4-0.9 more years with CD4 cell counts above 200 cells/µL (2-7% improvement), 0.3-0.7 more QALYs (2-5% improvement), and 0.02-0.06 fewer onward HIV transmissions (9-12% reduction) per person for all patient cohorts analyzed. Incremental cost-effectiveness ratios (ICERs) were lowest for MSM (£9,874 per QALY gained) and IDUs (£6,726 per QALY gained) and remained within typical UK willingness-to-pay thresholds for heterosexuals (£21,908 per QALY gained). Deterministic one-way sensitivity analysis showed that model results were robust.
CONCLUSIONS: Increased HIV-1 screening and immediate treatment initiation may be a cost-effective strategy to reduce HIV transmission and improve health for MSM, heterosexuals, and IDUs in the UK.
