Screening for Chlamydia trachomatis in asymptomatic women attending family planning clinics. A cost-effectiveness analysis of three strategies.

BACKGROUND Screening women for Chlamydia trachomatis in family planning clinics is associated with a reduced incidence of chlamydial sequelae. However, the question of whom to screen to maintain efficient use of resources remains controversial. OBJECTIVE To assess the cost-effectiveness of chlamydial screening done according to three sets of criteria in asymptomatic women attending family planning clinics. DESIGN Cost-effectiveness analysis done by using a decision model with the perspective of a health care system. Model estimates were based on analysis of cohort data, clinic costs, laboratory costs, and published data. SETTING Two family planning clinics in Baltimore, Maryland. PATIENTS 7699 asymptomatic women who presented between April 1994 and August 1996. INTERVENTION Three screening strategies--screening according to the criteria of the Centers for Disease Control and Prevention (CDC), screening all women younger than 30 years of age, and universal screening--were retrospectively applied and compared. All women were tested with polymerase chain reaction. MEASUREMENTS Medical outcomes included sequelae prevented in women, men, and infants. Total costs included screening program costs and future medical costs of all sequelae. The incremental cost-effectiveness ratios of each strategy were calculated. RESULTS Without screening, 152 cases of pelvic inflammatory disease would occur at a cost of $676,000. Screening done by using the CDC criteria would prevent 64 cases of pelvic inflammatory disease at a cost savings of $231,000. Screening all women younger than 30 years of age would prevent an additional 21 cases of pelvic inflammatory disease and save $74,000. Universal screening would prevent an additional 6 cases of pelvic inflammatory disease but would cost $19,000 more than age-based screening, or approximately $3000 more per case of pelvic inflammatory disease prevented. If the prevalence of C. trachomatis is more than 10.2% or if less than 88.5% of infections occur in women younger than 30 years of age, universal screening provides the greatest cost savings. CONCLUSIONS These results suggest that age-based screening provides the greatest cost savings of the three strategies examined. However, universal screening is desirable in some situations. In general, screening done by using any criteria and a highly sensitive diagnostic assay should be part of any chlamydial prevention and control program or health plan.