The 130th Annual Meeting of APHA

Abstract #50588

Peter Thomas, MPH¹, Julie Horrocks, PhD², Sherman James, PhD³, Matthew Boulton, MD⁴, Harold Pollock, PhD⁵, and Rosemary Rochford, PhD¹. (1) School of Public Health, Department of Epidemiology, The University of Michigan, 109 Observatory St., Rm 1009 SPH I, Ann Arbor, MI 48109-2029, 404 272-0173, petert@umich.edu, (2) Center For Statistical Consultation and Research, The University of Michigan, 1210 Buhr 837 Greene Street, Ann arbor, MI 48109-3213, (3) School of Public Health, University of Michigan, 1420 Washington Heights, Ann Arbor, MI 48109, (4) Department of Epidemiology, School of Public Health, The University of Michigan, 109 Observatory St., 1009 SPH I, Ann Arbor, MI 48109, (5) Department of Health Management and Policy, The University of Michigan, 109 Observatory St. M3224 SPH II, Ann Arbor, MI 48109-2029

Background: Chlamydia trachomatis causes reproductive health problems in millions of people, costing billions of dollars each year. However, its true prevalence remains uncertain, partly because many cases are asymptomatic. Although chlamydia has been a reportable disease in Michigan since 1993, no evaluation of screening efforts has been reported. Using STD and Family Planning (FP) clinic data, this study considers the yield and positive predictive value (PPV) of screening criteria for chlamydia. Purpose: The purposes are three fold: To describe individuals that screen positive for chlamydia, To determine how risk factors are associated with testing positive, and To evaluate the PPV and yield of CDC/Michigan Department of Community Health (MDCH) screening criteria. Methodology: Surveillance data from persons attending the 9 MDCH/CDC Infertility Prevention Project sites were used for the analysis. Results: Logistic regression showed that age (<25 years), OR=3.1, (2.7, 3.6) and "contact" with someone infected, OR=1.95 (1.4, 2.6), were the criteria most associated with testing positive. At STD clinics, only age was associated (p.< 0.0001). Clinic type modified the association of screening criteria and positivity. Using criteria from the FP model detected 92% of cases, screening 82% of the population to achieve a 5.2% PPV. In STD clinics, testing anyone <20 years had a PPV of 17%, yielding 43% of cases. Using criteria from the STD model detected 94% of cases, screening 84% of the population to achieve an 11% PPV. Conclusion: The MDCH/CDC chlamydia screening criteria predict infection in FP and STD clinics in Michigan

Learning Objectives:

• - Describe the clinical and social demographics of persons who test postive for chlamydia
• - Identify how family planning and STD clinics differ with respect to the risk factors and the sociodemographics of clients.
• - Establish a screening protocol that will identify the risk factors that best predict chlamydial infection in either STD or FP clinics

Keywords: Chlamydia, Screening

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.