Table 1 Data extraction from the literatures

Amer et al. [14]

Early recovery patterns of olfactory disorders in COVID-19 patients; a clinical cohort study

Cohort retrospective in 96 subjects

Age 31–40 years

Female

OR = 60.547; p ≤ 0.001

OR = 10.557; p = 0.005

Babaei et al. [15]

Factors associated with anosmia recovery rate in COVID-19 patients

Cohort retrospective in 235 subjects

Smoking

Ageusia

OR = 10.813; p = 0.031

OR = 5.340; p ≤ 0.001

Coelho et al. [16]

Predictors of smell recovery in a nationwide prospective cohort of patients with COVID-19

Cohort prospective in 798 subjects

Age < 40 years

Nasal congestion

p ≤ 0.003

p ≤ 0.03

Ferreli et al. [17]

Trigeminal features in COVID-19 patients with smell impairment

Cohort retrospective in 98 subjects

Trigeminal nasal sensations

OR = 6.176; p = 0.013

Teaima et al. [18]

Patterns and clinical outcomes of olfactory and gustatory disorders in six months: prospective study of 1031 COVID-19 patients

Cohort prospective in 1031 subjects

Parosmia

OR = 1.787; p = 0.0003