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Meta-Analysis
. 2022 Apr:117:155-161.
doi: 10.1016/j.ijid.2022.02.004. Epub 2022 Feb 5.

Systematic review and meta-analysis of olfactory and gustatory dysfunction in COVID-19

Nanyang Liu  1 , Di Yang  2 , Tingting Zhang  3 , Jiahui Sun  4 , Jianhua Fu  5 , Hao Li  6
Affiliations
Meta-Analysis

Systematic review and meta-analysis of olfactory and gustatory dysfunction in COVID-19

Nanyang Liu et al. Int J Infect Dis. 2022 Apr.

Abstract

Background: Chemosensory disorders associated with COVID-19 have been widely discussed during the pandemic. We performed a meta-analysis to assess the risk factors for olfactory and gustatory dysfunction in patients with COVID-19.

Methods: Three databases (PubMed, Embase, and Cochrane Library) were searched for studies published between December 1, 2019, and August 31, 2021. We selected random-effects model or fixed-effects model to pool data based on heterogeneity. The results were reported as odds ratios (ORs) or standardized mean differences (SMDs) and the corresponding 95% confidence intervals (CIs). Heterogeneity was reported as I2.

Results: Twenty-six studies with a total of 13,813 patients were included. The pooled data indicated that sex (OR 1.47; 95% CI 0.93-2.31), age (SMD -5.80; 95% CI -13.35 to 1.75), smoking (OR 2.04; 95% CI 0.72-5.79), and comorbidity (OR 1.21; 95% CI 0.58-2.53) of patients with COVID-19 had no effect on gustatory dysfunction. Olfactory dysfunction was more likely to occur in older patients with COVID-19 (SMD, -5.22; 95% CI, -8.28 to -2.16). Patients with COVID-19 with nasal congestion (OR 3.41; 95% CI 2.30-5.06) and rhinorrhea (OR 2.35; 95% CI 1.60-3.45) were more prone to olfactory dysfunction.

Conclusion: These findings emphasize that older patients with COVID-19 are more likely to experience olfactory dysfunction. Symptoms of nasal congestion and rhinorrhea may affect the recognition of olfactory dysfunction.

Keywords: COVID-19; Chemosensory disorders; Gustatory dysfunction; Meta-analysis; Olfactory dysfunction; SARS-CoV-2; Systematic review.

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Conflict of interest statement

Declaration of Competing Interest The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1
Figure 1
Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram.
Figure 2
Figure 2
Forest plot of sex, age, smoking, and comorbidity on the risk of gustatory dysfunction in patients with COVID-19. CI, confidence interval; GD, gustatory dysfunction; MD, mean difference; OD, olfactory dysfunction; OR, odds ratio; SD, standard deviation.
Figure 3
Figure 3
Forest plot of sex, smoking, and comorbidity on the risk of olfactory dysfunction in patients with COVID-19. CI, confidence interval; OD, olfactory dysfunction; OR, odds ratio.
Figure 4
Figure 4
Forest plot of age on the risk of olfactory dysfunction in patients with COVID-19. CI, confidence interval; MD, mean difference; OD, olfactory dysfunction; SD, standard deviation.
Figure 5
Figure 5
Forest plot of nasal congestion and rhinorrhea on the risk of olfactory dysfunction in patients with COVID-19. CI, confidence interval; OD, olfactory dysfunction; OR, odds ratio.
See this image and copyright information in PMC

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