We studied 1,763 Chinese older adults with normal cognitive function and 121 Chinese older adults with
early cognitive impairment (Clinical Dementia Rating global score 0.5). Normative MMSE values were derived for each
of the 15 strata classified by age (three groups) and education level (five groups). Receiver operating characteristic
curve analysis was conducted for the whole sample and each of the three education subgroups (no education, primary,
secondary and above)