Cost effectiveness analysis of a population based screening programme for asymptomatic Chlamydia trachomatis infections in women by means of home obtained urine specimens

Objectives: To evaluate the cost effectiveness of a systematic screening pr ogramme for asymptomatic Chlamydia, trachomatis infections in a female inne r city population. To determine the sensitivity of the cost effectiveness a nalysis to variation in the probability of developing sequelae. Methods: A decision tree was constructed to evaluate health effects of the programme, such as averted sequelae, of chlamydial infection. Cost effectiv eness from a societal perspective was estimated for screening by means of a ligase chain reaction on mailed, home obtained urine specimens, in a popul ation with a C trachomatis test prevalence of 2.9%. An extensive sensitivit y analysis was performed for the probability of sequelae, the percentage of preventable pelvic inflammatory disease (PID), and the discount rate. Results: The estimated net cost of curing one woman, aged 15-40 years, of a C trachomatis infection is US$1210. To prevent one major outcome (PID, tub al factor infertility ectopic pregnancy, chronic pelvic pain, or neonatal p neumonia), 479 women would have to be screened. The net cost of preventing one major outcome is $15 800. Changing the probability of PID after chlamyd ial infection from 5% to 25% decreases the net cost per major outcome avert ed from $28 300 to $6380, a reduction of 78%. Results were less sensitive t o variations in estimates for other sequelae. The breakeven prevalence of t he programme ranges from 6.4% for the scenario with all probabilities for c omplications set at the maximum value to a prevalence of 100% for probabili ties set at the minimum value. Conclusions: Systematic screening of all women aged 15-40 years for asympto matic C trachomatis infections is not cost effective. Although the results of the analyses are sensitive to variation in the assumptions, the costs ex ceed the benefits, even in the most optimistic scenario.