TABLE II.
Pooled Prevalence of Olfactory Dysfunction in Different Subgroups of COVID‐19 Patients.
| Subgroups of COVID‐19 Patients | Olfactory Dysfunction Prevalence [95% CIs] (%) | Number of Studies Analyzed | Total Number of COVID‐19 Patients | Heterogeneity | Publication Bias, Egger's Test (P Value) | |
|---|---|---|---|---|---|---|
| I 2 (%) | P Value | |||||
| Olfactory dysfunction in different regions | ||||||
| Europe | 54.40 [46.19–62.61] | 49 | 20,738 | 99 | <.0001 | .19 |
| North America | 51.11 [41.10–61.13] | 7 | 1,148 | 87 | <.0001 | NA |
| Asia | 31.39 [18.26–44.51] | 22 | 3,477 | 99 | <.0001 | .66 |
| Australia | 10.71 [0.00–22.17] | 1 | 28 | NA | NA | NA |
| Different types of olfactory dysfunction | ||||||
| Anosmia | 35.39 [27.73–43.04] | 43 | 10,979 | 99 | <.0001 | .11 |
| Hyposmia | 36.15 [27.65–44.64] | 24 | 5,200 | 98 | <.0001 | .003 |
| Dysosmia | 2.53 [0.0–6.0] | 1 | 79 | NA | NA | NA |
| Evaluation types of olfactory dysfunction | ||||||
| Subjective | 44.53 [37.59–51.47] | 73 | 26,229 | 99 | <.0001 | .60 |
| Objective | 72.10 [59.41–84.79] | 10 | 1,263 | 97 | <.0001 | .33 |
| Olfactory dysfunction based on clinical severity | ||||||
| Severe | 9.02 [2.67–15.38] | 4 | 687 | 85 | .001 | NA |
| Non‐severe | 47.48 [21.34–73.62] | 8 | 5,135 | 100 | <.0001 | NA |
CIs = confidence intervals; NA = not applicable.