Understanding the Prevalence and Risk Factor Profile of Olfactory Impairment and Its Impact on Patient Health Indicators and Economic Outcomes in Community-Dwelling Older Asian Adults

Abstract

Background and Objectives There is a paucity of data on the prevalence, risk factors and impact of olfactory impairment (OI) on key health indicators and economic outcomes in Asian populations. We aimed to address these gaps in a population of community-dwelling older adults. Research Design and Methods We included 2,101 participants (mean age ± SD: 72.9 ± 8.1 years; 55.1% women) from the baseline assessment of the Population Health and Eye Disease Profile in Elderly Singaporeans (PIONEER) study (2017-2022). Any OI was based on a score of <11 on the 16-item identification segment of the Sniffin' Sticks test battery; sub-categorized into hyposmia (score 9-10) and anosmia (score ≤ 8). Sociodemographic, clinical and lifestyle risk determinants, health indicators (health-related quality of life, depressive symptoms, daily caloric intake, frailty, and cognitive impairment [CI]) and economic outcomes (healthcare expenditure, productivity loss) were assessed via standardized clinical testing and/or validated questionnaires. Multivariable logistic and linear regression models were utilized to explore the risk factor profile of OI across its severity spectrum and its impact on health indicators and economic outcomes. Results The census-adjusted prevalence of any OI, hyposmia, and anosmia were 34.0%, 20.5% and 13.5%, respectively. Older age and male gender were associated with increased likelihood of hyposmia and anosmia, while the presence of diabetes and >4 days/week alcohol consumption were associated with increased odds of having anosmia only (all p <0.05). Both hyposmia and anosmia were also associated with more than 2-fold increased odds of having CI. Discussion and Implications Over a third of our community-dwelling older Singaporean population had OI, with one-in-ten experiencing total olfaction loss. Those with OI had more than double the odds of having CI, regardless of its severity. Our results suggest the importance of community-based programs aimed at detecting and delaying the progression of OI in high-risk individuals.