Improving the cost-effectiveness of Chlamydia screening with targeted screening strategies

Chlamydia is the most common sexually transmitted infection in the UK and constitutes a major public health problem. The UK Department of Health is phasing in a National Chlamydia Screening Programme (NCSP) but there is concern that blanket screening of the entire at risk population will simply add extra burden to the already overstretched health economy. This paper demonstrates that certain high-risk sub-groups within the general population are critical in the infection dynamics. Improved targeting of these high-risk populations achieves greater cost-effectiveness. Statistical risk-group clustering techniques have been used to identify indicators that are strong predictors in determining high-risk status while geomapping techniques visually display prevalence geographically across the region, thus identifying high prevalence postcode clusters and informing public health planners where to target intervention and screening strategies. A System Dynamics simulation model has been used to capture the infection dynamics and measure the cost-effectiveness of the intervention strategies. The model incorporates risk-group behaviour as identified by the above geomapping and statistical analysis components of the research. The combined use of computer simulation, statistical analysis and geomapping methodologies has provided a unique holistic view of the problem.