Factors associated with AD8-defined high cognitive risk in community-dwelling middle-aged and older adults: a cross-sectional study

Background With the accelerating global population aging, cognitive dysfunction has become an important public health challenge among middle-aged and older adults. The Ascertain Dementia 8-item Informant Questionnaire (AD8) is a simple and sensitive screening tool for identifying individuals at risk of cognitive impairment in community settings. However, evidence regarding factors associated with AD8-defined high cognitive risk (AD8 positivity) among community-dwelling middle-aged and older adults remains limited. This study aimed to investigate factors associated with AD8 positivity in a large community-based population. Methods A total of 7,601 participants were included in the descriptive and univariate analyses. All 14 candidate variables were entered into the multivariable logistic regression model, which was fitted using complete cases ( n = 7,293). Household economic status was retained a priori based on previous epidemiological evidence. Results Among the 7,601 participants, 6,116 (80.5%) were classified as having AD8 positivity. Univariate analyses showed that thirteen of the fourteen candidate variables were significantly associated with AD8 positivity. Multivariable logistic regression identified nine factors independently associated with AD8 positivity. Advanced age, female sex, marital status, poor self-rated health, depressive symptoms, and sleep disturbances were positively associated with AD8 positivity, whereas higher educational attainment and regular physical activity were negatively associated with AD8 positivity (indicating a lower risk). In addition, household economic status remained significantly associated with AD8 positivity after adjustment for potential confounders. Conclusion AD8 positivity was highly prevalent among community-dwelling middle-aged and older adults in this study population. Age, sex, marital status, educational level, household economic status, regular physical activity, self-rated health, depressive symptoms, and sleep disturbances were independently associated with AD8 positivity. These findings may help identify vulnerable populations and provide evidence for community-based cognitive health management and early intervention strategies.