Factors associated with anosmia recovery rate in COVID‐19 patients

Abstract

Abstract Objectives The present study aimed to assess the 4‐ and 8‐week recovery rate of anosmia and determine the factors associated with recovery in COVID‐19 patients. Method This retrospective study was conducted from December 2020 to March 2021. RT‐PCR‐proven COVID‐19 adult patients (over 18 years of age) with a positive history of anosmia were included in this study. Anosmia was assessed based on the COVID‐19 Anosmia Reporting Tool. The recovery rate of anosmia after 4 and 8 weeks were evaluated, and the relationship between the patients' recovery and their clinical and demographic data was assessed. Results A total of 235 patients were included. Their mean age (±SD) was 43.95 ± 15.27 years. Anosmia recovery was reported in 207(88.51%) and 219 (93.19%) participants till 4 and 8 weeks. The mean recovery time was 19.42 ± 8.81 days. The result of logistic regression showed that smoking (P = .031; OR = 10.813), ageusia (P = .002; OR = 5.340), headache (P = .006; OR = 0.243), and nasal discharge (P < .001; OR = 0.080) were significantly associated with 4 weeks anosmia recovery. The only risk factor which was associated with a lower rate of 8 weeks anosmia recovery was presence of nasal discharge (OR = 0.106, P = .002). Conclusion The only risk factor which was associated with a lower rate of 8 weeks anosmia recovery was presence of nasal discharge. Our result demonstrated that although smoking was associated with higher recovery rate till 4 weeks, it could not be considered as a protective factor after 8 weeks. More studies are recommended to investigate the relationship between anosmia and the associated factors by consideration of both short‐ and long‐term recovery rates and assess the possible mechanisms that could justify this association. Levels of Evidence 3b

Keywords

• ageusia
• anosmia
• COVID‐19
• olfaction disorders
• smoking