Cost-effectiveness of HIV nonoccupational post-exposure prophylaxis in Australia

The aim of the study was to determine the cost-effectiveness of HIV nonoccupational post-exposure prophylaxis (NPEP) in Australia.

A retrospective cost analysis of a population-based observational cohort of 1601 participants eligible for NPEP in Australia between 1998 and 2004 was carried out. We modelled NPEP treatment costs and combined them with effectiveness outcomes to calculate the cost per seroconversion avoided. We estimated the cost-utility of the programme, and sensitivity and threshold analysis was performed on key variables.

The average NPEP cost per patient was A$1616, of which A$848 (52%) was for drugs, A$331 (21%) for consultations, A$225 (14%) for pathology and A$212 (13%) for other costs. The cost per seroconversion avoided in the cohort was A$1 647,476 in our base case analysis, and A$512,410 when transmission rates were set at their maximal values. The cost per quality-adjusted life-year (QALY) was between A$40,673 and A$176,772, depending on the risks of HIV transmission assumed.

In our base case, NPEP was not a cost-effective intervention compared with the widely accepted Australian threshold of A$50,000 per QALY. It was only cost-effective after receptive unprotected anal intercourse exposure to an HIV-positive source. Although NPEP was a relatively well-targeted intervention in Australia, its cost-effectiveness could be improved by further targeting high-risk exposures.