Cognitive impairment using education-based cutoff points for CMMSE scores in elderly Chinese people of agricultural and rural Shanghai China

To evaluate cognitive impairment (CI) in rural China using the Chinese version of the Mini-Mental Status Examination (CMMSE) and compare the prevalence of CI using two different cutoff points.A population-based survey was conducted of 2809 people aged 60 years and above in a community of two towns (Huaxin and Xujing) in the Qingpu district, located in the western suburb of Shanghai. Face-to-face interviews were carried out to collect relevant information with questionnaires. The Chinese version of the Mini-Mental State Examination with either a 23/24 cutoff point or a cutoff point varying according to education level (AEL) was used to screen subjects for CI.Among these subjects, the mean age was 70.6 years (SD = 6.6) and ranged from 60 to 92 years and included 1010 (36.0%) men and 1799 (64.0%) women. The mean age was 70.7 years (SD = 6.4) for men and 70.5 years (SD = 6.7) for women. Of the 2809 subjects, 2010 (71.5%) had no formal education, 607 (21.6%) completed 1-6 years of education, and 173 (6.2%) completed more than 6 years of school education. The prevalence of CI was 35.6% (95% CI: 33.8-37.4) for both genders when the cutoff point of 23/24 was used. However, when the cutoff point was altered with respect to different education levels, the prevalence of CI was 7.0%. For each item of the CMMSE, increased years of education correlated with a higher item score, with the exception of the 'Naming' item score.This study demonstrates that screening of CI using the AEL cutoff scores is feasible in a low-education population. Determining whether the 23/24 cutoff point is suitable for the Chinese people requires future prospective studies in a large Chinese population.