TY - JOUR
T1 - Mild cognitive impairment in a community sample
T2 - The Sydney Memory and Ageing Study
AU - Brodaty, Henry
AU - Heffernan, Megan
AU - Kochan, Nicole A.
AU - Draper, Brian
AU - Trollor, Julian N.
AU - Reppermund, Simone
AU - Slavin, Melissa J.
AU - Sachdev, Perminder S.
PY - 2013/5
Y1 - 2013/5
N2 - Background: Mild cognitive impairment (MCI) is associated with an increased dementia risk. This study reports incidence of MCI subtypes, rates of progression to dementia, and stability of MCI classification. Methods: We examined 873 community-dwelling adults aged 70 to 90 years over 2 years as part of an ongoing population-based longitudinal study, the Sydney Memory and Ageing Study. Neuropsychological testing assessed five cognitive domains, and a diagnosis of no cognitive impairment, MCI, or dementia (follow-up only) was made according to published criteria. Results: The incidence of MCI was 104.6 (95% confidence interval: 81.6-127.7) per 1000 person-years, with higher incidence in men (men, 156.8; women, 70.3). Incidence rates for single-domain amnestic, multiple-domain amnestic, single-domain nonamnestic, and multiple-domain nonamnestic MCI were 47.7, 7.9, 45.0, and 3.9 per 1000 person-years, respectively. The 2-year rate of progression from MCI at baseline to dementia was 4.8%, being highest for multidomain amnestic MCI (9.1%). Of those with MCI at baseline, 28.2% reverted to no cognitive impairment at follow-up. Sensitivity analyses by redefining criteria for cognitive impairment did not affect stability of diagnosis, although changing the threshold of domain impairment reduced baseline MCI prevalence from 36.7% to 5.7% and incidence to 23.5, and increased 2-year progression rate from MCI to dementia to 14.3%. Conclusions: Incidence rates for MCI are higher than previously reported, particularly in men and for single-domain MCI; rates for amnestic and nonamnestic MCI were comparable. Multidomain amnestic MCI was the most likely subtype to progress to dementia, but overall, the diagnosis of MCI, particularly single-domain MCI, shows considerable instability.
AB - Background: Mild cognitive impairment (MCI) is associated with an increased dementia risk. This study reports incidence of MCI subtypes, rates of progression to dementia, and stability of MCI classification. Methods: We examined 873 community-dwelling adults aged 70 to 90 years over 2 years as part of an ongoing population-based longitudinal study, the Sydney Memory and Ageing Study. Neuropsychological testing assessed five cognitive domains, and a diagnosis of no cognitive impairment, MCI, or dementia (follow-up only) was made according to published criteria. Results: The incidence of MCI was 104.6 (95% confidence interval: 81.6-127.7) per 1000 person-years, with higher incidence in men (men, 156.8; women, 70.3). Incidence rates for single-domain amnestic, multiple-domain amnestic, single-domain nonamnestic, and multiple-domain nonamnestic MCI were 47.7, 7.9, 45.0, and 3.9 per 1000 person-years, respectively. The 2-year rate of progression from MCI at baseline to dementia was 4.8%, being highest for multidomain amnestic MCI (9.1%). Of those with MCI at baseline, 28.2% reverted to no cognitive impairment at follow-up. Sensitivity analyses by redefining criteria for cognitive impairment did not affect stability of diagnosis, although changing the threshold of domain impairment reduced baseline MCI prevalence from 36.7% to 5.7% and incidence to 23.5, and increased 2-year progression rate from MCI to dementia to 14.3%. Conclusions: Incidence rates for MCI are higher than previously reported, particularly in men and for single-domain MCI; rates for amnestic and nonamnestic MCI were comparable. Multidomain amnestic MCI was the most likely subtype to progress to dementia, but overall, the diagnosis of MCI, particularly single-domain MCI, shows considerable instability.
KW - Dementia
KW - Incidence
KW - Mild cognitive impairment
UR - http://www.scopus.com/inward/record.url?scp=84876940808&partnerID=8YFLogxK
U2 - 10.1016/j.jalz.2011.11.010
DO - 10.1016/j.jalz.2011.11.010
M3 - Article
C2 - 23110866
AN - SCOPUS:84876940808
VL - 9
SP - 310
EP - 317
JO - Alzheimer's and Dementia
JF - Alzheimer's and Dementia
SN - 1552-5260
IS - 3
ER -