Missed Opportunities for Chlamydia Trachomatis (CT) Retesting and Implications for Structural Interventions at the Clinic Level: Differences in Retesting Rates by Type of Return Visit within the California Family Planning (FP) Setting

Background:  CT reinfection is common and associated with adverse reproductive complications, yet retesting rates remain low in FP settings. 

Objectives: To describe clinic return and retesting patterns by visit type among female CT cases in California FP settings to inform structural interventions for improved opportunistic retesting.

Methods: Using 2007 Quest laboratory data and Family PACT claims, we determined the proportion of a CT-positive female cohort returning for services and retested 2-6 months post-diagnosis.  Return and retesting rates were stratified by visit type categories defined hierarchically using diagnostic codes and clinic, laboratory, and pharmacy claims.

Results: Overall, 82,186 female Family PACT clients were tested for CT by Quest in 2007; 3.2% (n=2,594) tested positive.  Forty-nine percent of cases returned for services 2-6 months post-diagnosis, and, of these, 50% were retested at their first return visit, giving an overall 25% retesting rate.  The reinfection rate was 15%.  Of 1,267 first-return visits, 26% were symptom-related, 23% birth control (BC) consults without pelvic exam, 10% limited-service pregnancy testing (PT) or emergency contraception (EC), 9% Pap smears, 9% STD-testing-only, 6% limited-service BC refills, 5% extended-services for PT, 3% abnormal Pap follow-up, and 11% could not be categorized.  Retesting rates varied significantly by return visit type, with lowest rates among abnormal Pap follow-ups (12%), limited-service BC refills (22%), and limited-service PT or EC (23%).  Retesting rates were highest among visits for STD-testing-only (96%), Pap smears (86%), and symptoms (69%).   

Conclusions: Although nearly half of female CT cases in California FP settings return for services during the recommended retesting period, CT retesting is missed at 50% of first visits.  Limited-service visits are least likely to trigger retesting by providers.

Implications for Programs, Policy, and/or Research: Simple structural interventions (e.g., chart prompts and trigger questions on history/exam forms) could improve opportunistic retesting regardless of reason for visit.  Improving opportunistic retesting may detect reinfections earlier and reduce adverse reproductive consequences.