Using the Mini-Mental State Examination for tracking cognition in the older population based on longitudinal data.

Objectives: To estimate population norms for use in assessment of individuals in relation to their age-matched peers using true longitudinal patterns of decline.
Design: Longitudinal study of 10 years of follow-up data from the Medical Research Council Cognitive Function and Ageing Study (MRC CFAS) on the most commonly used cognitive test across clinical and research settings.
Setting: England and Wales.
Participants: Thirteen thousand four people were seen in five sites at baseline, with follow up at 2, 5, and 10 years.
Measurements: Mini-Mental State Examination (MMSE) score at three interviews over 10 years. A total of 42,777 MMSE scores were used in the analysis.
Results: MMSE norms are presented according to age and split according to sex using longitudinal data. Potential cohort effects and dropout of individuals with low MMSE scores have been accounted for.
Conclusion: It is likely that the cognitive MMSE scale will continue to be used in many settings and across the age range. The figures presented here can be used to plot individual performance and chart where there is change in the relative position of one individual compared with others.