Differential evolution of cognitive impairment in nondemented older persons: results from the Kungsholmen Project.
OBJECTIVE
This study was a prospective, population-based examination of the evolution of cognitive impairment, no dementia (CIND).


METHODS
Subjects 75 years old or older living in Stockholm were assessed at baseline and 3 and 6 years later. The severity of CIND was based on age- and education-specific norms on the Mini-Mental State Examination and was classified as mild (N=212), moderate (N=96), or severe (N=57). Mortality, progression to dementia (DSM-III-R), cognitive stability, and cognitive improvement were studied as main outcomes.


RESULTS
Of the individuals with mild CIND, 63 (34%) died, 65 (35%) progressed to dementia, 21 (11%) remained stable, and 46 (25%) improved between baseline and first follow-up. The relative risks of progressing to dementia by first follow-up in the subjects with mild, moderate, and severe CIND were 3.6, 5.4, and 7.0, respectively. The relative risk of death decreased with increasing severity of impairment. Individuals who improved at first follow-up did not have a significantly higher risk of later progressing to dementia than subjects who had never been impaired (relative risk=1.4). The absence of a subjective memory complaint predicted improvement (odds ratio=5.4).


CONCLUSIONS
CIND is a heterogeneous condition: similar proportions of subjects progress to dementia, death, and cognitive improvement over 3 years. There is no increased future risk of progressing to dementia in CIND subjects who improve during that period.
Palmer
Katie
K
Stockholm Gerontology Research Center and Division of Geriatric Epidemiology, Department of Clinical Neuroscience, Occupational Therapy and Elderly Care Research, Uppsala University, Sweden. katie.palmer@neurotec.ki.se
Wang
Hui-Xin
HX
Bäckman
Lars
L
Winblad
Bengt
B
Fratiglioni
Laura
L
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology; D015897:Comorbidity; D003704:Dementia / Q000175:diagnosis / Q000453:epidemiology; D018450:Disease Progression; D004522:Educational Status; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008609:Mental Status Schedule / Q000706:statistics & numerical data; D011379:Prognosis; D011446:Prospective Studies; D012306:Risk; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology