Fig. 3.

Severely ill patients with COVID-19 are associated with a significantly lower risk of smell disorder. The table summarizes the number of patients with loss of smell (LOS) and the total number of confirmed COVID-19 cases who were either severe or non-severe from 34 reports. For each analysis (grey boxes), the forest plot shows the estimated odds ratio (OR) for the association of LOS with severe COVID-19 cases, with a 95% confidence interval (CI; horizontal black lines). The estimated pooled OR (grey diamond) was 0.527 (95% CI 0.373–0.744), which was significantly different from 1 (p < 0.001), according to a two-sided test. A random-effects model was used to calculate effects and summaries