Age-related differences in olfactory training outcomes: A prospective cohort study.

Abstract

While olfactory function decreases with age, it is unknown how age affects olfactory training (OT) efficacy. This study compared OT in two cohorts of subjects: aged ≤50 (younger cohort) and aged 51+ (older cohort) with olfactory dysfunction (OD) primarily from COVID-19 infection. Subjects with OD primarily secondary to COVID-19 infection were prospectively recruited and enrolled into an OT registry. Baseline data were collected and they were provided with a training kit and asked to complete OT at home twice daily for 6 months. Participants were asked to follow-up at 3 and 6 months during training for olfactory testing and quality-of-life surveys (Sino-Nasal Outcomes Test-22 [SNOT-22] and Questionnaire of Olfactory Disorders Negative Statements [QoD-NS]). Fifty-six participants completed OT (younger cohort: n=26, older cohort: n=30). There were no significant differences between cohorts' Affordable Rapid Olfactory Measurement Array (AROMA), QoD-NS, or SNOT-22 scores at any time point. Both cohorts showed significant AROMA score improvement of more than 16 points from baseline to 3 months (younger cohort: p=0.001; older cohort: p=0.008). The younger cohort had significant improvements in QoD-NS (p=0.008) and SNOT-22 (p=0.042) between baseline and 3 months while the older cohort improved from 3 to 6 months (QoD-NS: p=0.027, SNOT-22: p=0.049). Both cohorts demonstrated similar significant improvement in olfactory function after 3 months of OT. The timeline of subjective improvement was different between cohorts, with younger patients experiencing earlier improvement.