Date: June 25th, 2021

Guest Skeptic: Dr. Chris Bond is an emergency medicine physician and assistant Professor at the University of Calgary. He is also an avid FOAM supporter/producer through various online outlets including TheSGEM.

Reference: Chinnock et al. Self-obtained vaginal swabs are not inferior to provider-performed endocervical sampling for emergency department diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis. AEM June 2021

Case: A 31-year-old female presents to the emergency department with pelvic pain and vaginal discharge for the past 24 hours. She is afebrile, vital signs are normal and she is having a significant amount of pain. She says the pain is so severe that she cannot even imagine having a pelvic exam done right now for STI testing.

Background: Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) are the two most common sexually transmitted infections (STI) reported in the United States. Emergency departments (EDs) now diagnose an increasing percentage of NG/CT cases compared to STI clinics. (1,2)

The standard of care for NG/CT diagnosis is nucleic acid amplification testing (NAAT), with the collection method being provider-performed endocervical sampling (PPES). PPES is uncomfortable for patients and has numerous other limitations, including the need for exam rooms, an available provider and often a female chaperone. These limitations can delay sample collection and can also add significant delay in a busy ED. The need for universal pelvic examination in the ED to perform STI testing has also come under increasing scrutiny. (3)

Vaginal sample collection with self-obtained vaginal swabs (SOVS) was first developed and researched in non-ED settings based on these reasons and others. These studies demonstrated comparable sensitivity for NG/CT diagnosis when comparing SOVS to PPES, and high patient acceptability. (4-8)

However, those studies were performed in a wide range of non-ED settings and were mostly asymptomatic screening rather than STI testing in an acute care environment. This study compares PPES with SOVS in an ED setting and explores patient’s acceptability or preference of SOVS versus PPES.

Clinical Question: Do self-obtained swabs have noninferior sensitivity for the diagnosis of NG/CT compared to provider performed swabs in an ED setting using a rapid NAAT.

Reference: Chinnock et al. Self-obtained vaginal swabs are not inferior to provider-performed endocervical sampling for emergency department diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis. AEM June 2021

* Population: Female patients 18 years of age or older who were judged by the treating practitioner to need NG/CT testing

* Exclusions: Incarcerated any acute psychiatric condition precluded understanding instructions or giving informed consent, not English or Spanish proficient, or treated for NG/CT within the previous four weeks.

* Intervention: Self-obtained vaginal swab (SOVS) for NG/CT

* Comparison: Provider performed endocervical sampling swab for NG/CT

* Outcome:

* Primary Outcome: Noninferiority of SOVS sensitivity for NG/CT, with noninferiority being demonstrated if sensitivity was 90% or above.

* Secondary Outcomes: Kappa measurement of the SOVS and PPES, SOVS organism-specific sensitivity for NG and CT, acceptance rate of SOVS, rate of patients worried about doing SOVS correctly, and SOVS refusal rate.

This is an SGEMHOP episode which means we have the lead author on the show. Dr Brian Chinnock is Professor in Department of Emergency Medicine at the UCSF-Fresno Medical Education Program, and Research Director.