Impact of post-COVID-19 olfactory disorders on quality of life, hedonic experiences and psychiatric dimensions in general population.

Abstract

Background and objective: Olfactory disorders in COVID-19 alter quality of life and may cause psychic impairments. Olfactory disorders represent a prevalence between 8% to 85% and persist in up to 30% of COVID-19 cases. The main objective of this study is to evaluate the impact at 6 months of the post-COVID-19 olfactory disorders on quality of life, hedonic experiences and dimensions of anxiety and depression in general population. The second objective is to compare objective and subjective evaluations of olfactory disorders using these same criteria. Methods: It was a prospective, longitudinal (baseline (T0) and 6 months (T1)) open-label cohort study. The study population persistent olfactory disorders post-COVID-19 for more than 6 weeks. Olfactory disorders were assessed with Sniffin' Sticks Test® (TDI score) and a Visual Analogue Scale. An Olfactive Disorder Questionnaire and the French version of the Quality of life and diet questionnaire were used to evaluate patients’ quality of life. Hedonic experiences were assessed with Snaith-Hamilton Pleasure Scale and Anxiety and Depression dimensions with The State-Trait Anxiety Inventory, The Post Traumatic Stress Checklist Scale and Hamilton Rating Scale for Depression. At T0 and T1, the study population was separated on “normosmic” (NG) and “olfactory disorder” (ODG) groups based on TDI score. Results: 56 patients were recruited (58.93% women and 41.07% men) with 39.04 years old on average and post-COVID-19 olfactory disorder for an average of 5.32 months. At T1, the ODG have a significantly lower quality of life and hedonic experiences compared to the NG. There is no significant difference between the two groups for the dimensions of anxiety and depression. Objective and subjective assessments at T0 were significantly correlated with quality of life and hedonic experiences in both groups. At T1, the subjective evaluation of the NG was significantly correlated with all the criteria while the ODG only correlated with the hedonic experiences. Conclusion: Patients with post-COVID-19 olfactory disorders persistent for more than 6 months presented a degraded quality of life and hedonic experience. The subjective evaluation influenced the quality of life and the dimension of anxiety and depression more than the olfactory disorder itself. ClinicalTrials.gov number (ID: NCT04799977).