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. 2020 Jun 11;22(6):e19855.
doi: 10.2196/19855.

Epidemiological Observations on the Association Between Anosmia and COVID-19 Infection: Analysis of Data From a Self-Assessment Web Application

Fabrice Denis  1 , Simon Galmiche  2 , Aurélien Dinh  3 , Arnaud Fontanet  2 , Arnaud Scherpereel  4 , Francois Benezit  5 , François-Xavier Lescure  6   7
Affiliations

Epidemiological Observations on the Association Between Anosmia and COVID-19 Infection: Analysis of Data From a Self-Assessment Web Application

Fabrice Denis et al. J Med Internet Res. .

Abstract

Background: We developed a self-assessment and participatory surveillance web application for coronavirus disease (COVID-19), which was launched in France in March 2020.

Objective: Our objective was to determine if self-reported symptoms could help monitor the dynamics of the COVID-19 outbreak in France.

Methods: Users were asked questions about underlying conditions, sociodemographic status, zip code, and COVID-19 symptoms. Depending on the symptoms reported and the presence of coexisting disorders, users were told to either stay at home, contact a general practitioner (GP), or call an emergency phone number. Data regarding COVID-19-related hospitalizations were retrieved from the Ministry of Health.

Results: As of March 29, 2020, the application was opened 4,126,789 times; 3,799,535 electronic questionnaires were filled out; and 2,477,174 users had at least one symptom. In total, 34.8% (n=1,322,361) reported no symptoms. The remaining users were directed to self-monitoring (n=858,878, 22.6%), GP visit or teleconsultation (n=1,033,922, 27.2%), or an emergency phone call (n=584,374, 15.4%). Emergency warning signs were reported by 39.1% of participants with anosmia, a loss of the sense of smell (n=127,586) versus 22.7% of participants without anosmia (n=1,597,289). Anosmia and fever and/or cough were correlated with hospitalizations for COVID-19 (Spearman correlation coefficients=0.87 and 0.82, respectively; P<.001 for both).

Conclusions: This study suggests that anosmia may be strongly associated with COVID-19 and its severity. Despite a lack of medical assessment and virological confirmation, self-checking application data could be a relevant tool to monitor outbreak trends.

Trial registration: ClinicalTrials.gov NCT04331171; https://clinicaltrials.gov/ct2/show/NCT04331171.

Keywords: COVID-19; anosmia; epidemiological surveillance; epidemiology; outbreak; self-assessment; surveillance; symptoms; web application.

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Conflict of interest statement

Conflicts of Interest: FD received personal fees from AstraZeneca, Ipsen, Sivan Innovation, Pfizer, Chugai, Takeda, and Roche. All other authors declared no conflicts of interest.

Figures

Figure 1
Figure 1
Flowchart of the study population.
Figure 2
Figure 2
Maps displaying the correlation between fever and/or cough and anosmia with hospitalizations for COVID-19. (A) The cumulative number of hospitalized COVID-19–positive patients in France on March 29, 2020. (B) Fever and/or cough reported by users via the application; cumulative amount in French counties from March 17-29, 2020: 3,799,535 respondents (828,952 with fever and 1,515,557 with cough). (C) Anosmia reported by users; cumulative number from March 21-29, 2020: 325,910 positive respondents.
See this image and copyright information in PMC

References

    1. Denis F, Basch E, Septans A, Bennouna J, Urban T, Dueck AC, Letellier C. Two-Year Survival Comparing Web-Based Symptom Monitoring vs Routine Surveillance Following Treatment for Lung Cancer. JAMA. 2019 Jan 22;321(3):306–307. doi: 10.1001/jama.2018.18085. http://europepmc.org/abstract/MED/30667494 - DOI - PMC - PubMed
    1. Basch E, Deal AM, Dueck AC, Scher HI, Kris MG, Hudis C, Schrag D. Overall Survival Results of a Trial Assessing Patient-Reported Outcomes for Symptom Monitoring During Routine Cancer Treatment. JAMA. 2017 Jul 11;318(2):197–198. doi: 10.1001/jama.2017.7156. http://europepmc.org/abstract/MED/28586821 - DOI - PMC - PubMed
    1. Luo H, Lie Y, Prinzen FW. Surveillance of COVID-19 in the General Population Using an Online Questionnaire: Report From 18,161 Respondents in China. JMIR Public Health Surveill. 2020 Apr 27;6(2):e18576. doi: 10.2196/18576. https://publichealth.jmir.org/2020/2/e18576/ - DOI - PMC - PubMed
    1. Guerrisi C, Turbelin C, Blanchon T, Hanslik T, Bonmarin I, Levy-Bruhl D, Perrotta D, Paolotti D, Smallenburg R, Koppeschaar C, Franco AO, Mexia R, Edmunds WJ, Sile B, Pebody R, van Straten E, Meloni S, Moreno Y, Duggan J, Kjelsø Charlotte, Colizza V. Participatory Syndromic Surveillance of Influenza in Europe. J Infect Dis. 2016 Dec 01;214(suppl_4):S386–S392. doi: 10.1093/infdis/jiw280. - DOI - PubMed
    1. maladiecoronavirus.fr. 2020. [2020-03-17]. https://maladiecoronavirus.fr/

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