The Cost-Effectiveness of Screening Asymptomatic Men for Chlamydia to Prevent Pelvic Inflammatory Disease (PID) in Women T Gift 1, EF Dunne 1, J Chapin 1, C Kent 2, C Gaydos 3, JM Marrazzo 4, J Ellen 3,C Rietmeijer 5, J Schillinger 1, LE Markowitz 1 1 Centers for Disease Control and Prevention, Atlanta, GA 2 San Francisco Department of Public Health, San Francisco, CA 3 Johns Hopkins University School of Medicine, Baltimore, MD 4 University of Washington School of Medicine, Seattle, WA 5 Denver Public Health, Denver, CO

Background Data from demo project and longitudinal study: –prevalence and re-infection –partners (pre-screening and follow-up) –symptoms –cost of screening activities, by venue Data from literature: –sequelae and sequelae costs –STD visit costs –Data used in female screening comparison model Schillinger, et al. Sex Transm Dis 30:49-56, 2003, and others

Model Construction & Assumptions Index male is screened and tests positive for CT

Model, Continued Male has recent partner(s), who may be infected

Model, Continued Average number of recent partners: % of infected males’ partners infected 16% of infected partners seek treatment if not notified by DIS

Model, Continued Male may have partners during the follow-up period (4 months)

Model, Continued Average number of partners during follow-up: 1.2 Male may infect them if: –he is re-infected (12%) –his original infection is not treated (15%) If women infected, they are assumed to seek treatment on their own at the same rate as past partners (16%)

Model, Continued We assumed male is screened opportunistically (cheaply) Cost per index male for testing: $14.37 Cost of treatment: $22.50 Prevalence of CT among men screened = 6.0% –based on 6.6% positivity

For comparison purposes –convenience-based screening –same re-infection rate as with men (12%) –patient referral for partners (no DIS field work) 25% of asymptomatic partners seek care if referred Model, Continued-Screening Women

Results for Men * Program alternativeProgram cost for 1000 men † Cases of PID per 1000 men ‡ No screening 2, Screening / no PN18, Screening / PN20, * At baseline prevalence of 6.0% † Costs in 2001 US dollars ‡ Cases of PID in men’s female partners

Results for Men * Program alternativeProgram cost for 1000 men † Sequelae cost averted ‡ No screening 2,070 Screening / no PN18,0403,300 Screening / PN20,0304,940 * At baseline prevalence of 6.0% † Costs in 2001 US dollars ‡ Compared to no screening; PID cost per case = $1303 Two costs used for PID: low = $1303, high = $3071

Results for Men * Program alternativeProgram cost for 1000 men † Sequelae cost averted ‡ Net cost of program § No screening 2,070 Screening / no PN18,0403,30014,740 Screening / PN20,0304,94015,090 * At baseline prevalence of 6.0% † Costs in 2001 US dollars ‡ Compared to no screening; PID cost per case = $1303 § Net cost of program = program cost – sequelae cost averted

Results for Women * Program alternativeProgram cost for 1000 women † Cases of PID per 1000 women Net program cost ‡ No screening 1, Screening / No PN16, ,330 * At baseline prevalence of 2.0% † Costs in 2001 US dollars ‡ PID cost per case = $1303

*Cost per case of PID = $1303 $14.99 Screening women at a prevalence of 1% costs the same (in terms of net program costs) as screening men at a prevalence of 6%, but averts fewer cases of PID 3.8 cases of PID averted0.8 cases of PID averted

*Cost per case of PID = $1303 $12.84 Screening women at a prevalence of 4.6% is as effective (in terms of cases of PID prevented) as screening men at a prevalence of 6% $14.99

*Cost per case of PID = $3071 $8.39 $6.34  3.6% 3.8 cases of PID averted 2.9 cases of PID averted

Limitations Results would differ with different partnership structures –value of treating men declines as partner numbers decline Partner management options for men’s partners limited to PN vs. no PN –other options (partner-delivered therapy) may yield different results Results would differ with more-costly non- opportunistic screening

Conclusions Screening men can benefit women by: –reducing the number of infectious men –leading to the treatment of asymptomatic women through PN Screening men can be cost-effective: –if the prevalence among unscreened women who can potentially be screened is lower than the prevalence among men who can be screened, all else equal e.g., men in detention settings vs. women > 25 or > 30 in family planning settings