# Relationship between COVID-19 and “three inflammations and one deafness”: a systematic review and meta-analysis

## TL;DR

This study finds no strong link between COVID-19 and certain inflammatory conditions and hearing issues, but results depend on how these conditions are diagnosed.

## Contribution

The study is the first to systematically review and meta-analyze the relationship between 'three inflammations and one deafness' and COVID-19.

## Key findings

- No overall significant association found between COVID-19 and 'three inflammations and one deafness'.
- Physician-diagnosed cases showed a significant link, while self-reported cases did not.
- Heterogeneity in results highlights the importance of standardized diagnostic criteria.

## Abstract

The relationship between “three inflammations and one deafness” (allergic rhinitis, pharyngitis, otitis media, tinnitus, and deafness) and coronavirus disease 2019 (COVID-19) is currently unclear, and this study aims to investigate their correlation.

We searched the relevant literature in three databases (Embase, Cochrane Library, and PubMed) from their inception through July 2024, and the investigator strictly reviewed the literature according to the screening criteria to determine the included studies. We extracted relevant data information and conducted quality assessment and meta-analysis.

From 5,950 records screened, five cohort studies were included. The pooled analysis using a random-effects model showed no statistically significant association between COVID-19 and “three inflammations and one deafness” (OR = 1.03, 95% CI: 0.85–1.26, P = 0.74), with substantial heterogeneity (I² = 89%, P < 0.001). Critically, subgroup analyses revealed that the diagnostic criteria for “three inflammations and one deafness” were a key source of this heterogeneity. A significant association was observed in studies using physician-diagnosed outcomes (OR = 1.30, 95% CI: 1.08–1.56, P = 0.006, I² = 0%), whereas no significant association was found in studies based on self-reported symptoms (OR = 0.89, 95% CI: 0.69–1.15, P = 0.38, I² = 96%). Analyses by specific conditions yielded mixed results: No significant association was observed for hearing loss (OR = 0.93, 95% CI: 0.69–1.25, P = 0.62). For allergic rhinitis (OR = 1.19, 95% CI: 0.47–3.02, P = 0.71) and tinnitus (OR = 1.11, 95% CI: 0.88–1.39, P = 0.38), the point estimates suggested potential positive trends, but the associations were not statistically significant, and confidence intervals were wide. Subgroup analyses by some regions and COVID-19 diagnostic criteria did not reveal consistent significant associations.

This meta-analysis found no consistent association between COVID-19 and “three inflammations and one deafness,” primarily due to significant heterogeneity. Evidence suggests a link between COVID-19 and physician-diagnosed “three inflammations and one deafness,” which strongly depends on the rigor of outcome assessment, highlighting the need for standardized clinical diagnoses in future research.

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023438076.