Swab-yourself Trial With Economic Monitoring and Testing for Infections Collectively (SYSTEMATIC): Part 1. A Diagnostic Accuracy and Cost-effectiveness Study Comparing Clinician-taken vs Self-taken Rectal and Pharyngeal Samples for the Diagnosis of Gonorrhea and Chlamydia

Abstract

Background Urogenital testing misses extragenital Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT). Extragenital self-sampling is frequently undertaken despite no robust RCT evidence of efficacy. We compared clinician-taken rectal and pharyngeal samples with self-taken samples for diagnostic accuracy and cost in MSM and females. Methods Prospective, convenience, sample in UK sexual health clinic. Randomised order of clinician and self-samples from pharynx and rectum, plus first catch urine (MSM) and vulvovaginal swabs (females), for NG/CT detection. Results Of 1793 participants (1284 females, 509 MSM), 116 had NG detected (75 urogenital site, 83 rectum, 72 pharynx); 9.4% infected females and 67.3% MSM were urogenital negative. 276 had CT detected (217 urogenital site, 249 rectum, 63 pharynx); 13.1% infected females and 71.8% MSM were urogenital negative. Sexual history did not identify those with rectal infections. Clinician-rectal and self-rectal positive percent agreements (PPA) for NG detection were 92.8% and 97.6%; clinician-rectal, and self-rectal PPA for CT detection were 95.6% and 97.2%. There was no difference in diagnostic accuracy between clinician and self-taken samples. Clinicians performed swabs quicker than participants so costs were lower. However, in asymptomatic people, non-qualified clinicians would oversee self-swabbing and these costs would be lower than clinician’s. Conclusions There was no difference in diagnostic accuracy of clinician compared with self-taken extragenital samples. Sexual history did not identify those with rectal infections so individuals should have extragenital clinician, or self-taken, samples. Clinician swabs cost less than self-swabs but in asymptomatic people, or doing home testing, their costs would be lower than clinician swabs. Trial Registration ClinicalTrials.gov NCT02371109

A Collaborative Intervention Between Emergency Medicine and Infectious Diseases to Increase Syphilis and HIV Screening in the Emergency Department

“…Promoting patient self-collection of pharyngeal and rectal swabs for gonorrhea/ chlamydia testing in the ED may help increase extragenital testing rates. 26 Further work is needed to identify additional barriers and improve testing rates, as patients with oral and/or rectal infections may often have negative urine/cervical/urethral testing depending on sexual practices. 27 Study limitations include the absence of clear follow-up data for patients with positive syphilis and HIV test results during the preintervention period.…”

Regular Testing of HIV and Sexually Transmitted Infections With Self-Collected Samples From Multiple Anatomic Sites to Monitor Sexual Health in Men Who Have Sex With Men: Longitudinal Study

“…However, with high positivity rates and high proportion of detectable CT or NG in the test kits, incorrect sampling was unlikely to be a major concern. Studies have shown comparable accuracy and consistency results between self-sampled and clinician-sampled specimens [ 15 , 16 ]. Third, we did not use a validated tool to score self-sampling.…”

“…The transition from on-site to online services for self-sampling and self-testing of STI has been shown to be effective in previous studies in the United Kingdom [ 13 , 14 ]. Also, a previous study of human papillomavirus (tested via oral fluid, penis, rectum specimens) in China and a study of CT and NG (tested via extragenital samples) in the United Kingdom showed comparable accuracy and consistency between self-sampled and clinician-sampled specimens in MSM [ 15 , 16 ].…”

Patients May Accurately Self-collect Pharyngeal and Rectal Specimens for Neisseria gonorrhoeae and Chlamydia trachomatis Infection: But Is There Benefit?

“…The report by Wilson et al is a valuable study confirming that patients can accurately self-collect pharyngeal and rectal samples for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae infections as well as trained clinicians [1]. The study was well-constructed with a large sample size.…”

“…Wilson et al additionally report that clinicians collected swabs faster, 30 sec on average, than study participants [1]. They interpret that as cost saving, however that difference in time might be negligible in a health system and might overestimate value in a cost analysis.…”