To evaluate the prevalence of MCI and its subtypes in the Faenza Project, using the Mini-Mental State Examination (MMSE).

Subjects living in the municipality of Faenza were clinically assessed. The diagnosis of MCI was achieved according to international criteria using a double-step procedure: first, we excluded subjects with dementia, functional impairment and MMSE< 24, leaving 6,745 persons. Then, the performance in different cognitive domains was considered and scores less than 1.5 standard deviations below the age- and education-adjusted norms on MMSE were settled as cut-offs. Four subtypes were identified: amnestic MCI, single non-memory MCI, multidomains non-amnestic, multidomains amnestic MCI.

2,720 (40.3%) participants met MCI criteria. Prevalence were 4% (amnestic MCI), 26.5% (single non-memory MCI), 4.4% (multidomains amnestic MCI), and 5.4% (multidomains non-amnestic MCI).

MCI is common among Italian elderly. In our study prevalence are higher than reported in other population-based studies. The use of MMSE with different operational criteria, diverse sampling and assessment procedure might explain such discrepancy. The role of MMSE to identify persons with mild cognitive deficits deserves concerns. However, MMSE is largely used in both clinical practice and research and has been suggested as a useful screening tool for assessing the degree of cognitive impairment in the guidelines for the Report of the Quality Standards Subcommittee of the American Academy of Neurology.