A recent study suggests that women, patients who had initially severe COVID-19 symptoms, and patients who had nasal congestion while having COVID-19 are less likely to regain their senses of smell and taste than those who do not fall into any of these categories.
The study, “Prognosis and persistence of smell and taste dysfunction inbpatients with COVID-19: meta-analysis with parametric cure modelling of recovery curves,” published in the British Medical Journal (BMJ. 2022;378:e069503), examined 18 studies comprising 3,699 patients from 4,180 records in a reconstructed individual patient data (IPD) meta-analysis.
The analysis showed that female sex was strongly associated with lower likelihood of recovering the sense of smell (odds ratio (OR) 0.52, 95% confidence interval (CI) 0.37 to 0.72) and taste (OR 0.31, CI 0.13 to 0.72). More severe smell dysfunction during COVID-19 was associated with lower likelihood of smell recovery (OR 0.48, CI 0.31 to 0.73) but not with taste recovery. Nasal congestion during COVID-19 was associated with lower likelihood of smell recovery (OR 0.42, CI 0.18 to 0.97). Age and smoking weren’t associated with smell recovery.
Based on this, parametric cure models done by the researchers projected that 5.6% and 4.4% of patients with COVID-19 might develop long-lasting, self-reported smell and taste dysfunction post-COVID-19, respectively, totaling approximately 15 million and 12 million patients worldwide, respectively. The study authors cautioned that healthcare facilities and personnel must be ready to treat this number of patients, which may create a heavy burden on existing systems.