Sex workers can be screened too often: a cost-effectiveness analysis in Victoria, Australia
- David P Wilson1,
- Kelly-Jean Heymer1,
- Jonathan Anderson1,
- Jody O'Connor1,
- Christine Harcourt1,2,
- Basil Donovan1,2
- 1National Centre in HIV Epidemiology and Clinical Research, The University of New South Wales, Sydney, Australia
- 2Sydney Sexual Health Centre, Sydney Hospital, Sydney, Australia
- Correspondence to Dr David P Wilson, Level 2, 376 Victoria Street, Darlinghurst, Sydney, NSW 2010, Australia;
Contributors DPW and BD conceived the design of the study. DPW developed the mathematical framework and wrote the paper. KJH contributed to the development of the mathematical framework, carried out all analyses, produced figures and assisted in the writing of the manuscript. JA determined all costs associated with screening and treatment, assisted with the economic calculations and assisted with editing the manuscript. JO and CH provided data of incidence of STIs in sex workers. BD also contributed to the writing of the paper and overseeing its message.
- Accepted 14 August 2009
- Published Online First 20 October 2009
Objectives Commercial sex is licensed in Victoria, Australia such that sex workers are required to have regular tests for sexually transmitted infections (STIs). However, the incidence and prevalence of STIs in sex workers are very low, especially since there is almost universal condom use at work. We aimed to conduct a cost-effectiveness analysis of the financial cost of the testing policy versus the health benefits of averting the transmission of HIV, syphilis, chlamydia and gonorrhoea to clients.
Methods We developed a simple mathematical transmission model, informed by conservative parameter estimates from all available data, linked to a cost-effectiveness analysis.
Results We estimated that under current testing rates, it costs over $A90 000 in screening costs for every chlamydia infection averted (and $A600 000 in screening costs for each quality-adjusted life year (QALY) saved) and over $A4 000 000 for every HIV infection averted ($A10 000 000 in screening costs for each QALY saved). At an assumed willingness to pay of $A50 000 per QALY gained, HIV testing should not be conducted less than approximately every 40 weeks and chlamydia testing approximately once per year; in comparison, current requirements are testing every 12 weeks for HIV and every 4 weeks for chlamydia.
Conclusions Mandatory screening of female sex workers at current testing frequencies is not cost-effective for the prevention of disease in their male clients. The current testing rate required of sex workers in Victoria is excessive. Screening intervals for sex workers should be based on local STI epidemiology and not locked by legislation.
Funding The National Centre in HIV Epidemiology and Clinical Research is funded by the Australian government Department of Health and Ageing, and is affiliated with the Faculty of Medicine, University of New South Wales.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.