Cost-effectiveness of screening asymptomatic women for Chlamydia trachomatis
OBJECTIVE To assess the cost-effectiveness of identifying asymptomatic carriers of Chlamydia trachomatis among adolescent males. DESIGN Cost-effectiveness analysis based on cohort analytic studies previously reported and average salaries and costs of medical care in Sweden. SETTING Adolescent males attending a primary care center for routine health checks. PARTICIPANTS Estimates of costs and benefits are based on a cohort of 1000 adolescent males and their female contacts. INTERVENTION Screening with enzyme immunoassay (EIA), either on leukocyte esterase (LE)--positive urine samples (LE-EIA screening) or on all urine samples (EIA screening), was compared with no screening (no treatment or contact tracing). The effects of confirming positive EIA results with a blocking assay and alternative antibiotic regimens on the outcome of the screening strategies were also evaluated. RESULTS Compared with no screening, the LE-EIA and EIA screening strategies reduced the overall costs when the prevalence of chlamydial infection in males exceeded 2% and 10%, respectively. Enzyme immunoassay screening achieved an overall cure rate that was 12.2% to 12.6% (95% confidence interval) better, but reduced the incremental savings by at least $2144 per cured male, in comparison with LE-EIA screening. Confirmation of positive EIA results reduced the overall cost of the LE-EIA screening strategy when the prevalence of C trachomatis among males was less than 8%. Compared with a 7-day course of doxycycline, a single oral dose of azithromycin administered under supervision in the clinic improved the cure rates of both EIA and LE-EIA screening strategies by 15.1% to 16.3% and 11.2% to 12.0%, respectively, while reducing the corresponding overall costs by 5% and 9%, respectively, regardless of the prevalence of chlamydial infection in males. CONCLUSION The use of LE-EIA screening combined with treatment of positive cases with azithromycin was the most cost-effective intervention strategy focusing on asymptomatic male carriers of C trachomatis. Positive EIA results should be confirmed when screening low-risk populations.