Olfactory dysfunction (OD) is a common sequela of SARS-CoV-2 infection, but its prevalence and associated factors beyond 2 years remain unclear. In this multicenter observational study, we assessed 155 recovered COVID-19 patients approximately three years after infection and included 170 age-matched healthy controls as a reference group. Demographic, clinical, psychological, and sleep-related data were collected through structured interviews. Olfactory function at the 3-year assessment was objectively evaluated using Toyota–Takagi (T OR 5.35, 95% CI 1.07–26.60; p = 0.033) and anxiety (HAMA ≥ 7; OR 10.54, 95% CI 1.21–91.82; p = 0.04) were associated with persistent T&T-defined quantitative OD, although the small number of outcome events limited statistical precision. These findings indicate that a small proportion of COVID-19 survivors have persistent objective OD 3 years after infection and that persistent OD is associated with anxiety and insomnia.
Hu et al. (Sun,) studied this question.