Prevalence of Mild Cognitive Impairment and Its Subtypes in the Heinz Nixdorf Recall Study Cohort

Aims: We investigated the prevalence of mild cognitive impairment (MCI) and its subtypes according to the original (MCI-original) and modified (MCI-modified; neglecting cognitive complaints) Petersen criteria. Methods: 4,145 subjects (aged 50-80 years) from a German population-based study completed a cognitive screening test and were poststratified into 2 groups with sample sizes of 1,125 for impaired and 3,020 for age-appropriate performance. Random samples of 445 impaired participants and 211 age-appropriate participants received a detailed neuropsychological evaluation. The prevalence of MCI was estimated by a bias correction estimator based on stratum weights. The association between MCI and age, gender and education was analyzed in a logistic regression model. Results: The estimated MCI prevalence was 7.8% (95% CI: 5.7-9.9%) for the original, and 12.1% (95% CI: 9.8-14.4%) for the modified criteria. In the MCI-original group, amnestic MCI subtypes were slightly less common than non-amnestic MCI subtypes (3.5 vs. 4.3%). MCI-original was associated with lower education and older age. In the MCI-modified group, the amnestic subtypes were more common than the non-amnestic MCI subtypes (7.8 vs. 4.3%), and MCI was associated with age, gender and education. Conclusions: Prevalence rates of MCI are high in the general population and vary considerably according to the criteria applied. Copyright (C) 2010 S. Karger AG, Basel