COVID Smell Tracker: A research-based mobile application to study smell loss in subjects with COVID-19 (Preprint)
BACKGROUND Smell loss has been an established symptom of the novel coronavirus. Despite this, the risk factors associated with potential smell loss has not been clearly established. An app was developed and utilized to collect demographics and subjective otolaryngology symptoms from volunteers across the world in order to determine outcomes and risk factors as it pertains specifically to anosmia. OBJECTIVE COVID Smell Tracker” is a smart phone application (app) developed to elucidate the onset, duration and risk factors associated with COVID-related smell loss. METHODS The app is publicly available on smartphone devices (www.covidsmelltracker.org). Users complete surveys around demographics, medical history, COVID status and symptomology. Deidentified responses were collated and analyzed using descriptive statistics. RESULTS Of the 266 users included, the majority were located in Europe (43%) and North America (33%). Male, Caucasian users were most common (54.9% and 61.7% respectively), followed by Indian (10.5%) and Latino (9.4%). The majority of users reported no COVID testing (63%). 164 users reported COVID-related symptoms, and 57% of them reported olfactory dysfunction. User whom were younger age (p = 0.0003) and with type A and B blood types (p = 0.021) experienced smell loss at higher frequencies. Dysgeusia was associated with 28-34% of patients with concomitant smell loss, versus 6%-9% in users without. Smell loss was described ass “sudden” (63%), occurring on average 3 days following the onset of any other symptom. Of those that reported resolution of their smell loss, 50% resolved in 1 week, with 75% resolution reported within 1 month. CONCLUSIONS The results herein correlate with other established COVID-related studies, despite relying on purely volunteered data from participants from around the world. This is the first study to suggest an association of age and blood type with smell loss, and requires further investigation. Mobile app use offers a novel method for safe, remote and granular insight into those suffering from infectious diseases like COVID-19.