Prevalence of decreased olfactory function in adults in a Brazilian population sample

• Older individuals with an 8% increased risk of developing loss of smell. • Low correlations between self-reported olfactory function and objective performance. • The sense of smell is often underestimated. To investigate the prevalence of undiagnosed olfactory changes in individuals over 40 and the associated factors. A cross-sectional study enrolled a group of adult and elderly patients who did not report any nasal issues or olfactory changes with a clear or highly probable causal connection. They were subjected to the University of Pennsylvania Smell Identification Test (UPSIT) and the Visual Analog Scale to evaluate olfactory capacity. Two hundred eighty-four volunteers participated. Among the elderly, 96.9% experienced olfactory changes, while 80.4% of the younger group did. There was a significant correlation between age and UPSIT results (Rho = 0.33, p < 0.001) in the elderly. A higher prevalence of olfactory impairment was found in the elderly (p < 0.001). The age predictor showed an OR of 1.081 (p < 0.01, 95% CI 1.03–1.12). Both elderly and adults reported similar rates of altered olfaction, at 14.5% and 14.3%, respectively. There was a higher prevalence and risk of developing decreased olfaction in the elderly, with an 8% greater risk of olfactory dysfunction for each passing year. 5.