Psychiatr Prax 2011; 38 - P37_EC
DOI: 10.1055/s-0031-1277902

Incidence of mild cognitive impairment – a systematic review

T Luck 1, M Luppa 1, S Briel 1, SG Riedel-Heller 1
  • 1Institute of Social Medicine, Occupational Health and Public Health, Leipzig University, Germany

Background/Objectives: Dementia is not only one of the most burdensome diseases for sufferers and their caregivers, but also one of the biggest challenges for developed countries and their health care systems. Subjects with Mild Cognitive Impairment (MCI) constitute a risk population for developing dementia and thus a population of clinical interest. This study reviews recent work on the incidence of MCI in the elderly.

Methods: Incidence papers were identified by a systematic literature search. Studies on incidence of MCI were considered if they identified ‘cognitively mild impaired’ subjects by application of the MCI criteria (self-reported and/or informant-reported cognitive complaints, preserved basic activities of daily living, cognitive impairment or decline in cognition evidenced by performance on objective cognitive tasks, preserved general cognitive functioning, and absence of dementia), used the ‘person-years-at-risk’ method, and were based on population-based or community-based samples.

Results: Nine studies were identified. Incidence of Amnestic MCI subtypes ranged between 9.9 and 40.6 per 1,000 person-years, and incidence of Non-amnestic MCI subtypes was found to be 28–36.3 per 1,000 person-years. Regarding any MCI, incidence rates of 51–76.8 per 1,000 person-years have been found. A higher risk of incident MCI associated with higher age, lower education, and hypertension.

Discussion/Conclusions: Incidence rates of MCI varied widely, and possible risk factors for incident MCI were analysed only to a limited extent. Findings call for an agreement concerning the criteria used for MCI and the operationalisation of these criteria (e.g. the use of consistent cut-offs in cognitive tests for the definition of objective cognitive impairment).

Funding: This review was published in affiliation with the Leipzig Research Centre for Civilization Diseases (LIFE, University of Leipzig). LIFE is financed by the European Union, by the European Regional Development Fund (ERDF) and by the Free State of Saxony within the framework of the Excellence Initiative.

Keywords: Outcome assessment, mild cognitive impairment, incidence.