Detection of subclinical Chlamydia trachomatis infection in women is a high but costly public health priority.
To develop and test simple selective screening criteria for chlamydia in women, to assess the contribution of cervicitis to screening criteria, and to evaluate cost-effectiveness of selective versus universal screening.
Cross-sectional study and cost-effectiveness analysis of 11,141 family planning (FP) and 19,884 sexually transmitted diseases (STD) female clients in Washington, Oregon, Alaska, and Idaho who were universally tested for chlamydia using cell culture, direct fluorescent antibody, enzyme immunoassay, or DNA probe.
Prevalence of cervical chlamydial infection was 6.6%. Age younger than 20 years, signs of cervicitis, and report of new sex partner, two or more partners, or symptomatic partner were independent predictors of infection. Selective screening criteria consisting of age 20 years or younger or any partner-related risk detected 74% of infections in FP clients and 94% in STD clients, and required testing 53% of FP and 77% of STD clients. Including cervicitis in the screening criteria did not substantially improve their performance. Universal screening was more cost-effective than selective screening at chlamydia prevalences greater than 3.1% in FP clients and greater than 7% in STD clients.
Age and behavioral history are as sensitive in predicting chlamydial infection as criteria that include cervicitis. Cost-effectiveness of selective screening is strongly influenced by the criteria's sensitivity in predicting infection, which was significantly higher in STD clients. At the chlamydia prevalences in the populations studied, it would be cost saving to screen universally in FP clinics and selectively in STD clinics, the reverse of current practice in many locales.
* From the Department of Medicine, University of Washington, Seattle, Washington, the †Division of STD/HIV Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, ‡James Bowman Associates, and the §Seattle-King County Department of Public Health, Seattle, Washington
The authors thank the following colleagues for contributions in the execution of this study: Dr. Ann Haddix, Dr. Walter E. Stamm, Dr. Laura Koutsky, and Dr. Debra J. Mosure for their thoughtful reviews of the manuscript; Ted Holzman, for assistance in computer-based analyses; the University of Washington Chlamydia Laboratory; and the many participating clinics, providers, and patients who made this study possible. The authors also cite the extraordinary efforts of Dr. Joseph Lossick (deceased), who guided the Region X Chlamydia Project through its first several years.
Supported in part by NIAID STD/AIDS Research Training Grant T32 AI-07140 (JMM) and the Centers for Disease Control and Prevention.
Reprint requests: Jeanne M. Marrazzo, MD, MPH, Broadway Clinic, Mailstop 359928, 1001 Broadway, Suite 320, Seattle, WA 98122.
Received for publication April 1, 1996, revised July 1, 1996, and accepted July 17, 1996.