Prevalence of olfactory dysfunction and quality of life in hospitalised patients 1 year after SARS-CoV-2 infection: a cohort study

OBJECTIVES: To determine the long-term prevalence of olfactory and/or gustatory dysfunction (OD±GD), associated risk factors and impact on quality of life (QoL) in previously hospitalised patients with COVID-19 1 year after infection. DESIGN: A single-centre cohort study. SETTING: Patients admitted at a large central London hospital with COVID-19 infection between 10 February 2020 and 22 May 2020. PARTICIPANTS: 150 adult subjects with previously confirmed SARS-CoV-2 infection were recruited between 10 December 2020 and 29 January 2021. Participants were predominantly male (102/150, 68.0%); mean age 58.0±15.9 years and 41.2% (56/136) were of black, Asian and minority ethnic backgrounds. MAIN OUTCOME MEASURES: EQ-5D-5L values and Sino-Nasal Outcome Test-22 (SNOT-22) scores. RESULTS: Long-term prevalence of OD±GD was 12.8% (19/149) at median time of 264.5 days following SARS-CoV-2 infection onset. Patients with OD±GD had a significantly higher median total SNOT-22 score (46.1; Q1–Q3: 23.0–60.0; 95% CI 23.0 to 60.0) compared with those without (16.0; Q1–Q3: 5.0–30.5; 95% CI 12.0 to 18.0) (p=0.0002), reflecting poorer QoL, particularly psychological well-being (p=0.0004), which was not alleviated with time (p=0.4977). Median EQ-5D-5L value was not significantly different between patients with OD±GD (0.70; Q1–Q3: 0.38–0.83; 95% CI 0.38 to 0.83) and those without (0.83; Q1–Q3: 0.61–0.94; 95% CI 0.75 to 0.89) (p=0.0627). Age, sex, ethnicity, smoking status, highest C reactive protein value, intubation and ventilation, and oxygen supplementation were not found to influence OD±GD (p>0.05). CONCLUSIONS: 12.8% of previously hospitalised patients with COVID-19 in London still report persistent problems with smell or taste up to a year after infection, impacting their QoL. Increased holistic support including psychological therapy and olfactory rehabilitation for affected patients may help to reduce long-term morbidity.