Strategic options for antenatal screening for syphilis in the United Kingdom: a cost effectiveness analysis

Antenatal screening for syphilis is well established in the United Kingdom. The prevalence of syphilis is now very low, prompting the question as to whether this screening programme is still necessary. This paper aims at identifying possible screening strategy options for the programme and comparing their effectiveness and cost effectiveness.

The cost of the screening programme in the United Kingdom was estimated. This was based on the cost of screening tests, treatment, and follow up of infected women and their infants. This information was obtained from laboratories, antenatal clinics, and genitourinary medicine clinics. Epidemiological data from a survey of women treated for syphilis in pregnancy were analysed to identify groups at increased risk of syphilis. Strategic options for the screening programme were then identified. The effectiveness, number needed to treat, and cost effectiveness of these options were compared.

Antenatal screening in the United Kingdom detected at least 40 pregnant women who need treatment for syphilis every year. This means that 18602 women are screened for every woman detected who needs treatment for syphilis. The marginal annual cost of this screening programme in the United Kingdom is 672366 pounds sterling. This is equivalent to 90p per woman screened, or 16670 pounds sterling to detect one woman who needs treatment for syphilis. The screening programme could be targeted geographically at pregnant women in the Thames regions. This option has the potential to save 482185 pounds sterling. Other strategic options are to target pregnant women in non-white ethnic groups, or those born outside the United Kingdom. These targeted options would each detect between 70% and 77% of women needing treatment for syphilis. These options could potentially save 592938 pounds sterling and 562691 pounds sterling respectively.

Targeting or stopping the screening programme would save relatively little money. Although selectively screening groups by country of birth or by ethnic group could detect at least 70% of cases, this would be politically and practically difficult. Targeting by region would facts and the changing international epidemiology of syphilis lead us to recommend that the current universal antenatal screening for syphilis should continue.