SCENTinel: A Rapid Smell Test for COVID-19 Surveillance

Adequate COVID-19 testing capacity is still lacking in much of the United States and around the world. Recent research suggests that the best predictor of a positive COVID-19 test result is the symptom of sudden smell loss – even better than other common symptoms, including fever or shortness of breath. Data from many studies indicate that a sudden loss of smell may be one of the earliest indicators of COVID-19, and objective measures of smell loss, like a smell test, detect up to 20% more COVID-19 cases compared with self-report. Team investigators have developed a quick smell test ("SCENTinel") that could potentially fill this testing gap, allowing for potential early identification of COVID-19 via home testing. Building on our experience developing the NIH Toolbox Odor Identification Test, we developed the SCENTinel test to be self-administered and expanded the assessment to include additional facets of olfactory experience (e.g., intensity), which may prove to be more sensitive to partial loss of smell. The purpose of this study is to build the validity evidence for the SCENTinel to (a) predict COVID-19 positivity, and (b) assess the psychometric validity of the SCENTinel using additional key criteria, namely test-retest reliability and validity correlations with existing gold-standard (examiner-administered) olfaction measures, increasing the evidence base to justify wider deployment.