Screening for Chlamydia trachomatis in Women 15 to 29 Years of Age: A Cost-Effectiveness Analysis

Abstract
Clinical guidelines have traditionally advised annual Chlamydia trachomatis screening for women younger than 25 years of age. To assess the cost-effectiveness of recently proposed strategies for chlamydia screening. State transition simulation model; cost-effectiveness analysis. Published literature. Sexually active U.S. women 15 to 29 years of age. Lifetime. Modified societal. Four strategies targeted to 3 specific age groups (15 to 19 years, 15 to 24 years, and 15 to 29 years): 1) no screening, 2) annual screening for all women, 3) annual screening followed by 1 repeated test within 3 to 6 months after a positive test result, and 4) annual screening followed by selective semiannual screening for women with a history of infection. Clinical events (for example, pelvic inflammatory disease, chronic pelvic pain, ectopic pregnancy, and infertility), lifetime costs, quality-adjusted life expectancy, and incremental cost-effectiveness ratios. Annual screening in women 15 to 29 years of age followed by semiannual screening for those with a history of infection was the most effective and cost-effective strategy. It consistently had an incremental cost-effectiveness ratio less than $25 000 per quality-adjusted life-year (QALY) compared with the next most effective strategy. When the indirect transmission effects of a 10-year screening program on the probability of infection in uninfected women (that is, per-susceptible rate of infection) were considered, all strategies became more cost-effective. Results were sensitive to the annual incidence of chlamydia, probability of persistent infection, screening test costs, and costs of treating long-term complications. Each variable was associated with threshold values beyond which screening became cost-saving. In probabilistic analysis, annual screening in women 15 to 29 years of age followed by semiannual screening for those with a history of infection had an incremental cost-effectiveness ratio less than $50 000 per QALY in 99% of simulations. Uncertainty about the natural history of chlamydial infection and consideration of only the indirect transmission effects of C. trachomatis screening. Annual C. trachomatis screening for all women 15 to 29 years of age and selective targeting of those with a history of infection for semiannual screening is very cost-effective compared with other well-accepted clinical interventions.