worldwide 1, 2 . Clinical manifestations of COVID-19 are often nonspecific, including fever, fatigue, cough, anosmia, and shortness of breath, and a subset of patients are completely asymptomatic throughout their disease course 1 . However, severe cases of COVID-19 can rapidly progress to acute respiratory distress syndrome (ARDS), respiratory failure, and death. Accurate diagnostic testing is crucial to identify both symptomatic patients and asymptomatic carriers to ensure adequate treatment and isolation measures, thus preventing further disease transmission.
Currently, COVID-19 is diagnosed using real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) tests that specifically detect SARS-CoV-2 2 . Clinical specimens are commonly obtained from areas with the highest viral load, including the lower respiratory tract (e.g. sputum, bronchoalveolar lavage) and upper respiratory tract (nasopharyngeal, nasal cavity, and oropharyngeal samples) [1] [2] [3] [4] [5] [6] [7] [8] [9] . While lower respiratory tract specimens carry higher viral loads and yield higher test sensitivity, risk of aerosolization and transmission to healthcare workers during specimen retrieval limits their clinical use 3, 4, 10 . Currently, the Centers for Disease Control (CDC) recommend upper respiratory tract sampling, with nasopharyngeal specimens as the Figure 1 written and video instruction regarding nasopharyngeal swab technique: insertion of swab through the nares until resistance is felt, rotation of swab for a few seconds to absorb secretions, and slow removal of the swab 1, 15 . Given that the nasopharynx is a structure posterior to the nasal cavity, it cannot be easily visualized externally by the testing provider. Challenges to providers who are not well-versed in nasal anatomy include poor understanding of nasopharynx location relative to the nasal cavity, inability to pass the swab through either nare, and subsequent patient and provider discomfort with COVID testing. This study aims to assess the effect of nasal anatomy and nasopharyngeal swab technique teaching by an otolaryngologist on provider comfort level and knowledge base for COVID testing.
After Institutional Board Review exemption was attained, surgical nursing coordinators recruited nursing staff to participate in an educational session reviewing nasal anatomy and technique pertaining to COVID testing. Inclusion criteria for this study included nursing providers who were required to perform COVID testing at this institution, and who were able to attend the educational session in its entirety. Providers who were unable to attend the educational session or who could not complete both the pre-and post-session surveys were excluded from the study.
Seventeen providers were enrolled in this study, consisting of surgical pre-operative nurses and labor and delivery nurses who were required to perform COVID testing in their respective units. A pre-session survey was conducted evaluating the total number of COVID tests performed by each provider, prior nasal testing experience, and prior nasal anatomy teaching received. Provider-reported challenges with COVID testing and provider comfort level with performing and teaching COVID testing were assessed. A 6-question nasal anatomy test was then administered to evaluate the provider's knowledge base of COVID testing (Figure 1) .
Questions included where a COVID test swab should be aimed, location of the nasal cavity and nasopharynx, and which sided nare a swab would more easily pass through when septal deviation or inferior turbinate hypertrophy was present. were able to identify the location of the nasopharynx (8 and 14, respectively, p=0.04) and the optimal nare to pass a swab through with asymmetric inferior turbinate hypertrophy (3 and 14, respectively, p=0.003). (Figure 2) .
Diagnostic specimens for COVID testing are retrieved from areas with high viral loads, specifically the upper and lower respiratory tracts. Lower respiratory tract specimens, such as bronchoalveolar lavage and sputum, contain greater viral loads and yield higher test sensitivity than upper respiratory tract specimens 3, 4 . However, an expert consensus by the Chinese Interventional Respiratory Medicine Group emphasizes that bronchoscopy should not be used routinely to diagnose COVID-19, due to risk of virus aerosolization and transmission to health care workers 10 . Concurrently, the CDC recommends upper respiratory tract sampling, with nasopharyngeal specimens as the preferred choice for initial diagnostic testing 1 . Similar to other respiratory viruses, SARS-CoV-2 is most readily detected in the nasopharynx due to higher viral load, as compared with the nasal cavity, nasal washings, or oropharynx 1,2,5-9,16-18 .
Nasopharyngeal COVID testing sensitivity relies on adequate specimen acquisition, safe specimen storage, and accurate rRT-PCR testing. Reported sensitivity of nasopharyngeal swab testing ranges from 38% to 78%, although the exact rate is still unknown 16, 19 . Multiple studies Figure 1 malfunctioning, and misinterpretation of expression profiles 11, 13 . One particular study by Li et al evaluating over 3,000 COVID tests done in Wuhan, China reported that one of the most likely causes of false negative testing is inadequate specimen acquisition 13 . Specifically, the authors posit that testing providers were often learning on the job, and a lack of training led to inconsistent specimen acquisition and variable test sensitivity 13 .
This study aimed to assess the effect of a formalized nasal anatomy and technique training session on medical providers' comfort level and knowledge base in performing accurate COVID testing. Almost all of the providers enrolled in this study had completed fewer than 10 COVID tests, and only half had performed any sort of nasal testing in the past. While the CDC has encouraged adopting the influenza testing technique for nasopharyngeal specimen retrieval, only 36% of those enrolled in this study had any experience performing influenza testing 1 . The inexperience with nasopharyngeal testing seen in our study population is not uncommon in the current resource-strained healthcare setting, as medical providers of various backgrounds are being tasked with COVID testing.
Prior to the educational session, only 5 of the 17 providers in this study felt comfortable independently performing a COVID test. Most providers acknowledged the nasopharynx as the optimal target for COVID swab testing, although only half correctly identified the nasopharynx on a sagittal image. Many providers were also unable to identify which nare to swab to avoid nasal obstruction (i.e. deviated septum, inferior turbinate hypertrophy), and some did not recognize that the nasopharynx could be accessed via either nare. This study found that after a 20-minute educational session provided by an otolaryngologist discussing proper nasopharyngeal swabbing technique and pertinent nasal anatomy, significantly more providers felt comfortable J o u r n a l P r e -p r o o f Figure 1 independently performing and teaching COVID testing. Almost all providers were able to locate the nasopharynx, and most were able to identify the correct nare to swab in the presence of nasal obstruction. These providers' improved knowledge base should theoretically address their reported COVID testing challenges. Patient discomfort and nasal bleeding from nasopharyngeal swabbing often result from trauma to the nasal septum, and identification of septal deviation may help providers avoid septal trauma with COVID testing. Knowledge that the nasopharynx can be accessed through either nare may also help providers troubleshoot unilateral nasal obstruction by passing a test swab through the contralateral nose.
Limitations to this study include small sample size and a single-institution experience.
The nurses referred for this educational session were either pre-operative surgical nurses or labor and delivery nurses, most of whom were not routinely performing nasal testing. As a more diverse group of medical providers are being tasked with COVID testing during the COVID-19 pandemic, it is even more imperative to provide adequate training to ensure testing accuracy. The nasopharynx carries a high viral load of SARS-CoV-2 that makes it an optimal target for diagnostic testing. Many testing providers may not understand the nasal anatomy or proper technique for attaining adequate nasopharyngeal specimen, thus leading to a high false-negative COVID testing rate. Early implementation of nasal anatomy education and nasopharyngeal swab technique training by the otolaryngologist can help improve medical provider comfort and knowledge base in performing more accurate COVID testing.
J o u r n a l P r e -p r o o f The 6-question test administered before and after the educational session to evaluate the provider's knowledge base of nasal anatomy related to COVID testing. 