Abstract
Introduction The number of positive cases and deaths from the coronavirus disease 2019 (COVID-19)
is still increasing. The early detection of the disease is very important. Olfactory
dysfunction has been reported as the main symptom in part of the patients.
Objective To analyze the potential usefulness of anosmia or hyposmia in the detection of the
COVID-19 infection.
Data Synthesis We systematically searched the PubMed Central database using specific keywords related
to our aims until July 31st, 2020. All articles published on COVID-19 and anosmia
or hyposmia were retrieved. A statistical analysis was performed using the Review
Manager (RevMan, Cochrane, London, UK) software, version 5.4. A total of 10 studies
involving 21,638 patients were included in the present analysis. The meta-analysis
showed that anosmia or hyposmia is significantly associated with positive COVID-19
infections (risk ratio [RR]: 4.56; 95% confidence interval [95%CI]: 3.32–6.24; p < 0.00001; I2 = 78%, random-effects modeling).
Conclusion The presence of anosmia or hyposmia is a good predictor of positive COVID-19 infections.
Patients with onset of anosmia or hyposmia should take the test or undergo screening
for the possibility of COVID-19 infection.
Keywords
coronavirus disease 2019 - COVID-19 - anosmia - hyposmia - olfactory dysfunction
