Are olfactory and gustatory symptoms useful at predicting disease severity markers in COVID-19 infection?

Context: The relationship between olfactory and gustatory dysfunction (OGD) and COVID-19 infection severity is still unclear.

Aim: To investigate the correlation between OGD in COVID-19-infected individuals and RT-PCR results, chest CT scan abnormality, lymphocyte counts, hospital admission units, age, body temperature, and blood oxygen saturation.

Setting and design: Case-control study.

Materials and methods: The sample was composed of laboratory and chest X-ray confirmed COVID-19-infected patients from four hospitals. The patients were divided into case and control groups based on the presence of OGD symptoms. The predictor variable was OGD. The outcome variable was gender, hospital admission unit, chest CT scan abnormality, PCR, lymphocyte counts, age, body temperature, and blood oxygen saturation.

Statistical analysis used: Bivariate statistics were computed and the P value was set at 0.05.

Results: The sample consisted of 189 patients. Smell and taste disorders were found in 31.7% and 24.3% of patients, respectively. OGD was significantly correlated with positive PCR results (P < 0.001) and general unit admission (P < 0.05) during hospitalization. Additionally, patients with OGD had significantly lower mean age (P < 0.001), higher body temperature (P < 0.01), and blood oxygen saturation (P < 0.01). However, OGD was not correlated with gender, chest CT scan abnormality, or lymphocyte counts (P > 0.05).

Conclusions: OGD symptoms can be used to detect COVID-19-infected patients. OGD can be used to predict less severe disease mainly by its correlation with the less amount of hospital care, more negative PCR results, higher body temperature, and higher blood oxygen saturation.