Smell and taste loss persists in 5.6% of COVID-19 patientsA systematic review and meta-analysis published yesterday in BMJ estimates that 5.6% of COVID-19 survivors may face long-lasting changes to their sense of smell or taste, adding to concerns about the overall burden of long COVID.National University of Singapore researchers led the analysis of 18 observational studies of 3,699 adults with 4,180 medical records reporting impaired taste or smell after COVID-19 infection up to Oct 3, 2021.
Nine studies were conducted in Europe, five in Asia, and four in North America. Average participant age range was 30.0 to 55.8 years, and the proportion of men ranged from 29.0% to 79.4%.Models of time-to-event data showed that lingering self-reported smell and taste impairments could affect about 5.6% of COVID-19 patients, but sensitivity analyses suggested that this figure may be an underestimate.Among all patients, 74.1%, 85.8%, 90.0%, and 95.7% regained their sense of smell by 30, 60, 90, and 180 days, respectively, and 78.8%, 87.7%, 90.3%, and 98.0% recovered their sense of taste by 30, 60, 90, and 180 days, respectively.Relative to men, women had lower probability of regaining their sense of smell (odds ratio [OR], 0.52; seven studies) and taste (OR, 0.31; seven studies), and patients with more severe initial impairment (OR, 0.48; five studies) and those with nasal congestion (OR, 0.42; three studies) were less likely to recover their sense of smell.The study authors said that clinicians often overlooked smell and taste dysfunction before the COVID-19 pandemic, perhaps because these senses were considered less important than vision and hearing. "As a result of the COVID-19 pandemic, patients and doctors may now be aware that