A cost-effectiveness analysis of screening and treatment for Chlamydia trachomatis infection in asymptomatic women.

OBJECTIVE To assess the cost-effectiveness of identifying and treating asymptomatic female carriers of Chlamydia trachomatis. DESIGN Cost-effectiveness analysis based on previously reported cohort analytic studies and average salaries and costs of medical care in Sweden. SETTING Women attending youth, family planning, and gynecology clinics. PARTICIPANTS 1000 women and their male sex partners. INTERVENTION Screening with tissue cell culture, confirmed enzyme immunoassay, and DNA amplification assays based on either polymerase chain reaction or ligase chain reaction was compared with no screening (no treatment and no tracing of sexual contacts). The effect of antibiotic regimens on the outcome of the screening strategies was also evaluated. RESULTS When the prevalence of chlamydial infection exceeded 6%, screening of women with DNA amplification assay and treatment of positive patients with a single oral dose of azithromycin given under supervision in the clinic was the most cost-effective intervention strategy. At greater prevalences, screening with enzyme immunoassay also generated savings and improved the cure rates compared with no screening, but such screening was less cost-effective than screening with a DNA amplification assay. Compared with no intervention, tissue cell culture is cost-effective only when the prevalence of infection is greater than 14%. Compared with the azithromycin regimen, the standard 7-day, twice-daily doxycycline regimen resulted in significantly lower cure rates because of patients' poor compliance with this regimen. CONCLUSION For asymptomatic female carriers of C. trachomatis, screening with a DNA amplification assay combined with the single-dose azithromycin treatment of positive patients is the most cost-effective strategy when the prevalence is 6%. When the prevalence is lower than 6%, the decision to choose a competing strategy depends on the physician's view of the value of preventing an illness caused by untreated chlamydial infection.