Mild cognitive impairment: prevalence and incidence according to different diagnostic criteria. Results of the Leipzig Longitudinal Study of the Aged (LEILA75+).
BACKGROUND
Although mild cognitive impairment is associated with an increased risk of developing dementia, there has been little work on its incidence and prevalence.


OBJECTIVE
To report age-specific prevalence, incidence and predictive validities for four diagnostic concepts of mild cognitive impairment.


METHODS
A community sample of 1045 dementia-free individuals aged 75 years and over was examined by neuropsychological testing in a three-wave longitudinal study.


RESULTS
Prevalence rates ranged from 3% to 20%, depending on the concept applied. The annual incidence rates applying different case definitions varied from 8 to 77 per 1000 person-years. Rates of conversion to dementia over 2.6 years ranged from 23% to 47%.


CONCLUSIONS
Mild cognitive impairment is frequent in older people. Prevalence, incidence and predictive validities are highly dependent on the diagnostic criteria applied.
Department of Psychiatry, University of Leipzig, Germany. krausem@medizin.uni-leipzig.de
Anja
A
Busse
Jeannette
J
Bischkopf
Steffi G
SG
Riedel-Heller
Matthias C
MC
Angermeyer
D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D003704:Dementia / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D012372:ROC Curve; D012680:Sensitivity and Specificity