The most commonly reported sexually transmitted disease in the United States is genital infection with Chlamydia trachomatis. Women not treated for this infection experience severe consequences, including pelvic inflammatory disease, ectopic pregnancy, chronic pelvic pain, and tubal infertility. Screening for C. trachomatis is the optimal way to diagnose this frequently asymptomatic infection. Multiple techniques using urine, cervical, or vaginal sampling are available for screening. The Centers for Disease Control and Prevention (CDC) recommends follow-up for women testing positive for C. trachomatis. Hu and associates used a computer-based mathematical model to simulate a representative group of sexually active women to analyze the cost-effectiveness of a variety of strategies for chlamydia screening.
The strategies the authors evaluated included: (1) no screening; (2) annual screening for all women; (3) annual screening for all women followed by one repeat test within three to six months after a positive test result; and (4) annual screening for all women except those with a history of at least one infection, who are rescreened every six months. Potential immediate adverse events and long-term outcomes were calculated. Annual incidence of infection assumptions varied depending on the range of ages included.
The results demonstrated that without screening the lifetime cost per woman of the disease is $340; the additional lifetime cost of screening ranged from $48 to $107, depending on the screening program used. Based on quality adjusted life-year costs, the most cost-effective strategy is to annually screen all sexually active women 15 to 29 years of age and to rescreen those with infection every six months. These estimates are based on assumptions about current infection rates, costs of screening, and the cost of treating pelvic inflammatory disease.
The authors conclude that this calculation and other clinical trials support extending the upper age for screening by the CDC from 25 to 29 years. Data are not available to evaluate the utility and cost-benefit of screening women older than 30 years.
editor’s note: In an editorial1 in the same journal, Stamm notes the costs and serious consequences that can result from chlamydia infections. Stamm supports screening, but notes that actual practice falls far short of recommended practice. He also recommends better funding and further education of physicians in the private sector. In addition to the groups suggested for screening by the Hu article, Stamm recommends screening of male adolescents with urine-based nucleic acid amplification test assays to uncover an important reservoir of infection. Testing technology that provides immediate results also would facilitate immediate diagnosis and treatment, but it is not available. At present, implementing current guidelines is a clear imperative.—r.s.