Patterns of Sexually Transmitted Infection-Related Testing and Diagnosis by Places of Service, MarketScan Commercial...

Understanding where people receive care for sexually transmitted infections (STI) is essential for optimizing STI service delivery.

Based on the date of service, the first encounter with STI testing or diagnosis for each patient aged ≥15 years was identified using MarketScan commercial claims data from 2023-2024. We identified chlamydia, gonorrhea and syphilis testing using Current Procedural Terminology codes (CPT) and diagnoses using International Classification of Diseases (ICD-10) codes. Encounters were classified as diagnosis encounters if they included an STI diagnosis, and as testing encounters if they included STI testing only. We appropriately identified place-of-service using an encounter-ordering approach, especially tracing laboratory claims to their origin.

A total of 2,964,733 STI-related encounters (98.6% for testing, 1.4% for diagnoses) were identified, including 82.7% for chlamydia (CT), 81.3% for gonorrhea (GC), and 50.0% for syphilis (TP). Among the encounters, office encounters accounted for the highest proportion (82.1%), followed by independent laboratories (12.2%) and emergency room (ER)/urgent care (UC)/acute care (AC) clinics (4.8%). Based on demographic characteristics, encounters were more frequent among people aged 30-34 years old (17.9%), women (74.5%) and people living in the South region (47.4%).

The predominance of STI testing-coded encounters indicates that most identified claims involved STI testing rather than diagnosis coding. However, claims data cannot distinguish routine screening from diagnostic testing and finding reflect encounter-based observations of claims, rather than inferring adherence to screening guidelines. Maintaining access to offices, independent laboratories, and ER/UC/AC clinics remains important for appropriate STI care.