[Changes in mild cognitive impairment and sociodemographic disparity among adults aged 55 years and above in 4 provinces of China].

OBJECTIVE:To investigate the changes in mild cognitive impairment(MCI) and sociodemographic disparity among adults aged 55 years and above in 4 provinces of China. METHODS:A total of 4687 adults aged 55 years and above from Community-based Cohort Study on Nervous System Disease who did not have Alzheimer's disease, participated in both rounds of the survey, and had complete baseline sociodemographic data and two rounds of data on cognitive function were selected. Generalized estimation equations were used to analyse the effect of sociodemographic factors on MCI. RESULTS:The detection rates of MCI in adults aged 55 years and above without Alzheimer's disease in 4 provinces of China in 2018 and 2020 were 48.56% and 42.56% respectively. MCI occurred in 30.11% of those with normal cognition(NC) at baseline, and 44.24% of those with MCI at baseline reverted to NC. The risk of MCI increased and the likelihood of MCI reversion decreased with increasing age and decreasing per capita monthly household income. In the baseline NC population, the risk of MCI in the junior high school and above group was 35% lower than that in the illiterate group(RR=0.65, 95%CI 0.53-0.80), the risk of MCI was lower in those living in rural areas(RR=0.56, 95%CI 0.49-0.65), and the risk of MCI was 1.17 times(95%CI 1.03-1.32) higher in those with a history of chronic diseases than in those without it. In the baseline MCI population, the likelihood of MCI reversion increased with education, the likelihood of MCI reversion was 1.04 times higher for workers than for non-workers(95%CI 1.00-1.08). CONCLUSION:The incidence and reversal rates of MCI were high in adults aged ≥55 years in four provinces of China. Advanced age, low education and low income level are risk factors for cognitive dysfunction.