Background: CDC recommends annual Chlamydia trachomatis (CT) screening in women age >25 years with risk factors. However, evaluation of specific screening criteria for this population has been limited. We investigated: 1) CT predictors in women aged 26-35 years screened at Region X IPP FP clinics; and, 2) potential screening algorithms.
Methods: We used 2009-11 Region X IPP and U.S. Census 2007-11 American Community Survey (ACS) records. IPP records operationalized client demographics, risk behaviors, clinical signs and CT test results. ACS records were used to generate area-based socioeconomic measures (ABSM), merged into IPP via client ZIP code. Only screened female FP clients aged 26-35 were included. We excluded females with diagnostic CT tests (records with signs, symptoms, CT exposure, symptomatic sex partner (SP), re-screening, pregnant, CT infection past year, or presumptive treatment). We calculated CT positivity (CT+) stratified by individual measures (demographics, risk behaviors) and ABSM (poverty, educational attainment, and Gini income inequality). Crude/adjusted odds ratios were generated by univariate and multivariate logistic regressions. Significant predictors were used to develop 11 screening algorithms and were assessed for efficiency (%test volume required), effectiveness (%positives detected), and CT+.
Results: Of 17,877 CT screening records, 67% were women aged 26-30; 59% white race; 78% urban. 8% reported multiple SPs; 17% indicated new SP (past 60 days). 15% reported SP with concurrent SPs. CT+ was 2.7%. Significant predictors were: age 26-30 years (3.0% CT+); multiple SPs (5.9%); new SPs (5.0%). Screening algorithms were efficient (<30%), but not effective (<50%) (CT+ range: 3.3%-5.9%). Including age 26-30 years improved effectiveness (>74%), but reduced efficiency (>67%) and CT+ (3.0%).
Conclusions: Efficient and effective screening algorithms were not identified for older female FP clients. Selective screening works best in populations with higher CT+. More work is needed to determine other risk factors to optimize screening in this clinic population.