Correlation of Subjective and Objective Measures of Olfaction : New insights from the COVID-19 pandemic

Sammanfattning: The Coronavirus disease 2019 (COVID-19) was in March 2020 classified by the World Health Organization as the second pandemic of the century and has currently infected over 521 million people. One common symptom related to COVID-19 is olfactory dysfunction, estimated to affect around 60% of all patients. However, it cannot be assumed that all patients correctly estimate their olfactory loss. The aim of this study was to investigate the correlation between subjective self-reported ratings of olfactory ability and objective psychophysical measures of olfactory function. Volunteers (N = 135) who continuously have been tested for seroprevalence of SARS-CoV-2-specific antibodies since the beginning of the pandemic were recruited among staff and patients at Danderyd Hospital, Stockholm, Sweden. Participants rated their subjective estimate of their olfactory abilities which were subsequently assessed using objective and validated psychometric tests. Data analyses were conducted to investigate whether correlations between subjective and objective olfactory measures would vary with SARS-CoV-2 antibody status and/or level of olfactory dysfunction. The principal findings were significant correlations between subjective and objective measures in the overall sample, the seropositive participants, and the participants with olfactory dysfunction; but with no significant correlation between named measures in the seronegative participants. In addition to findings contradicting current assumptions of no to low correlation between subjective and objective measures of olfaction, the results further address the importance of considering additional variables when investigating this relationship.