Five-item odorant test as an indicator of COVID-19 infection in a general population

Abstract

Purpose To analyze the utility of a 5-item odorant test ( U-Smell-It ™) in determining COVID-19 status in COVID-19 polymerase chain reaction (PCR)-positive and -negative participants. Methods Symptoms, COVID-19 status, and 5-item odorant test results were collected from general population COVID-19 testing in Louisiana ( n = 1042), and routine COVID-19 screening of healthcare workers in a nursing home in Florida ( n = 278) ( ClinicalTrials.gov Identifier: NCT04431908 ). Results In the general population COVID-19 testing site, a cutoff point of ≤2 (0, 1, or 2 correct answers out of 5) achieved sensitivity of 40.0% (95% CI: 26.4%–54.8%) and specificity of 89.2% (95% CI: 87.1%–91.1%) in detecting COVID-19 infection. Within this population, analysis of individuals with no self-reported loss of smell/taste and runny/stuffy nose resulted in sensitivity of 38.1% (95% CI: 18.1%–61.6%) and specificity of 92.3% (95% CI: 89.1%–93.4%), while analysis of individuals with self-reported loss of smell/taste and/or runny/stuffy nose resulted in sensitivity of 41.4% (95% CI: 23.5%–61.1%) and specificity of 82.4% (95% CI: 77.7%–86.5%). Conclusions The quick turnaround time, low cost, reduced resource requirement, and ease of administering odorant tests provide many advantages as an indicator sign to help flag a molecular diagnostic COVID-19 test with relatively high specificity. Our results suggest that this odorant testing for olfactory dysfunction may be a viable option in pre-screening COVID-19 infection. This tool has the potential to allow for continued monitoring and surveillance, while helping mitigate surges of COVID-19 variants. Further investigation is warranted to observe the extent to which odorant testing might be applied in a serial testing scenario.

The assessment of qualitative olfactory dysfunction in COVID-19 patients: a systematic review of tools and their content validity

“…These questions are specific to symptom characteristics, limiting the degree of interpretation. Patel et al (2022) did a cross-sectional study in the US, where they asked participants one screening question during consultations: "Does anything smell different in the last year?, " followed by the response alternatives "yes" and "no." Although the question describes parosmia, it allows for erroneous interpretation, as it does not directly exclude the experience of smelling odors that are not present or perceived by others.…”

Psychophysical Testing in Chemosensory Disorders

“…Using a cut-off score ≤ 4 in the symptomatic cohort, sensitivity was 85% and specificity was 39%. A cut-off ≤ 2 yielded 40% sensitivity with 89% specificity, demonstrating the importance of determining the purpose of an assessment for screening when determining cut-off scores [ 65 ].…”

The detection of smell disorder depends on the clinical tools

“…We read the paper of Patel et al entitled “Five-item odorant test as an indicator of COVID-19 infection in a general population [1] ”. Authors evaluated the reliability of the 5-item odorant test in determining the COVID-19 status in the general population.…”

“…Authors evaluated the reliability of the 5-item odorant test in determining the COVID-19 status in the general population. The authors used the real-time polymerase chain reaction (RT-PCR) to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, thus assessing different sensitivity and specificity levels of 5-odor testing [1] . We congratulate the authors for this interesting study because testing olfactory function as detection approach for SARS-CoV-2 infection is undoubtedly cost-effective.…”