Due to rising rates of vaccinated adults in the United States and potential harms from delayed healthcare, the American Gastroenterological Association (AGA) has updated its guidelines, released in July of 2020, on pre-endoscopy testing for SARS-CoV-2. The Association now recommends against routine testing. This guideline update was published in Gastroenterology.
The guideline panel was comprised of gastroenterologists, an expert in infectious diseases, and guideline methodologists. The panel implemented the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach, modified according to the Guidelines International Network/McMaster checklist for rapid recommendations. A literature search through May 1, 2021 found 42 evidence-based studies of COVID-19 and endoscopy. Patient safety, impacts from delayed care, health care worker safety, and health care burden were prioritized during guideline formulation.
The AGA recommends against routine SARS-CoV-2 testing prior to upper or lower endoscopy, regardless of vaccination status.
Thirteen studies evaluated asymptomatic infections among patients referred for endoscopy. The prevalence of asymptomatic infection ranged from 0.0% to 1.5%. The observed rates of COVID-19 infections among patients and health care workers following endoscopy in 8 studies were between 0% and 0.4% among patients and up to 4.0% among health care workers. The study that detected a 4% positivity rate among workers was an outlier, as 6 studies found no postprocedural infections among health care workers and another study detected COVID-19 among only 0.26% of staff.
No published studies have yet to incorporate the protection from vaccination into analysis of COVID-19 risk associated with endoscopy. With data from the Centers for Disease Control and Prevention (CDC), the guideline panel found that risk for testing positive for SARS-CoV-2 among vaccinated health care workers ranged from 0.5% to 1.19%.
Studies (n=14) have reported that the pandemic has caused between a 51% and 95% reduction in upper endoscopy and colonoscopy volumes, dependent on procedure type and timing during the pandemic. Due to the reduction in volume, a study from Canada projected it would take 41 months to complete backlogged procedures.
The impact on delayed or deferred procedures on gastrointestinal cancers was studied in 9 publications. Cancer detection rates were estimated to be reduced by 31% to 71% for colorectal cancer, 27% to 52% for gastric cancer, and 27% to 37% for esophageal cancer. Patients who underwent treatment for colorectal cancer during the pandemic were more likely to present with advanced disease compared with prepandemic trends.
On the basis of this evidence, the potential harms of delaying procedures in order to test all patients for SARS-CoV-2 outweigh the risk of exposing health care workers to infection, as there were few infections attributed to endoscopy procedures, and vaccinations have been relatively widespread among healthcare staff. The panel did note, however, that the certainty of this evidence was very low and was formulated on the basis of indirect evidence only.
The AGA recommends the use of rapid real time polymerase chain reaction (RT-PCR) or nucleic acid amplification tests (NAAT) over rapid isothermal or antigen tests for centers which continue to implement preprocedure SARS-CoV-2 testing.
A total of 6 studies compared lab-based RT-PCR, rapid RT-PCR, and rapid NAATs. No evidence was available for isothermal or antigen tests in the context of preprocedural assessment. Lab-based RT-PCR and rapid RT-PCR were found to have comparable sensitivities (0.99 vs 0.98) and specificities (0.98 vs 0.97). The lab-based tests had comparable specificities to rapid NAAT (0.98 vs 0.99), but had superior sensitivity (0.99 vs 0.81), respectively.
The panel recommends the use of rapid RT-PCR or NAAT assessments, as these results can be available in an hour, avoiding procedure delays, and the proportion of false positives or negatives is similar to lab-based assessment. The certainty of this evidence was deemed to be moderate to very low, as no evidence for antibody and isothermal tests were available in the endoscopy setting. However, evidence in other settings indicated antibody testing had low sensitivity (0.52) and was ineffective for asymptomatic cases.
These recommendations were formulated under the assumption that all centers have access to personal protective equipment and all patients have undergone universal screening for symptoms of COVID-19. These guidelines are subject to expire in 12 months.
Due to the increased understanding of disease transmission, low infection risk during endoscopy, and efficacy and distribution of SARS-CoV-2 vaccinations, the AGA no longer recommends routine COVID-19 testing prior to endoscopy. The potential harms due to delayed patient care outweigh the risks for viral transmission.
Sultan S, Siddique SM, Singh S, et al, on behalf of the AGA. AGA rapid review and guideline for SARS-CoV2 testing and endoscopy post- vaccination: 2021 update. Gastroenterol. Published online May 21, 2021. doi:10.1053/j.gastro.2021.05.039