New study evaluates different strategies for chlamydia screening

Increasing the efficiency of partner notification is more cost effective in preventing the spread of chlamydia than increasing the coverage of primary screening in men, according to new research from the University of Bristol, published in the BMJ.

Partner notification is an essential component of the management of all sexually transmitted infections.  About two thirds of the sexual partners of patients who test positive for chlamydia are also found to be infected.  In England, 65 per cent of male partners of chlamydia positive women were found to be infected, compared with 6 per cent of men tested through primary screening in 2008?9.

The researchers, led by Dr Katy Turner of Bristol’s School of Social and Community Medicine, used economical and mathematical modelling to compare the cost, cost effectiveness, and sex equity of different intervention strategies within the English National Chlamydia Screening Programme.

They also developed a tool for calculating the cost effectiveness of chlamydia control programmes at a local, national or international level.

In 2008?9 chlamydia screening was estimated to cost about £46.3m in total and £506 per infection treated.  Provision for partner notification within the screening programme cost between £9 and £27 per index case, excluding treatment and testing.

The model results suggest that increasing male screening coverage from 8 per cent (baseline value) to 24 per cent (to match female coverage) would cost an extra £22.9m and increase the cost per infection treated to £528.

In contrast, increasing partner notification efficacy from 0.4 (baseline value) to 0.8 partners per index case would cost an extra £3.3m and would reduce the cost per infection diagnosed to £449.  Increasing screening coverage to 24 per cent in men would cost over six times as much as increasing partner notification to 0.8 but only treat twice as many additional infections.

Dr Turner said: ’Within the current National Chlamydia Screening Programme , partner notification is an underused but highly effective strategy for increasing treatment of infected individuals, particularly men.  Partners of infected patients may be up to 10 times more likely to be infected than individuals identified through primary screening.

?Increasing the effectiveness of partner notification is likely to cost less than increasing male screening and also improve the ratio of women to men diagnosed.  We are especially excited about the spreadsheet tool we have developed which will help local services to evaluate their own programmes and allow rapid updates based on national reports.  We would be delighted to hear from anyone wishing to use this tool.  However, further evaluation of the cost effectiveness of partner notification and screening is urgently needed.’

Paper

’Costs and cost effectiveness of different strategies for chlamydia screening and partner notification: an economic and mathematical modelling study? by Katy Turner, Elisabeth Adams, Arabella Grant, John Macleod, Gill Bell, Jan Clarke, Paddy Horner BMJ