May 7, 2010
Licensing requirements in Victoria, Australia, call for commercial sex workers to undergo regular STD testing. However, the incidence and prevalence of STDs among licensed sex workers are very low because condom use at work is almost universal. The study authors conducted a cost-effectiveness analysis of this testing policy versus the health benefits of averting the transmission of HIV, syphilis, chlamydia and gonorrhea to clients.
The researchers used a simple mathematical transmission model informed by conservative parameter estimates from all available data and linked to a cost-effectiveness analysis. They estimated that under current testing rates, it costs $90,000 (US $80,130) in screening for every chlamydia infection averted (and $600,000 [US $533,684] for each quality-adjusted life year [QALY] saved) and more than $4 million (US $3.6 million) for every HIV infection averted ($10 million [US $8.9 million] for each QALY saved). At an assumed willingness to pay of $50,000 (US $44,444) per QALY gained, HIV testing should not be performed less than approximately every 40 weeks and chlamydia about once a year. Current requirements call for HIV testing every 12 weeks and chlamydia screening every four weeks.
"Mandatory screening of female sex workers at current testing frequencies is not cost-effective for the prevention of disease in their male clients," the researchers concluded. "The current testing rate required of sex workers in Victoria is excessive. Screening intervals for sex workers should be based on local STD epidemiology and not locked by legislation."