Abstract
Background: Mild cognitive impairment is increasingly recognized as an important public health problem associated with increased risk of developing dementia. Annual conversion rates, however, vary across different studies with clinic samples showing higher rates of conversion than community-based samples. Objectives: To establish whether the rates of conversion from mild cognitive impairment to dementia differed according to recruitment source and, if so, to investigate factors that might explain this discrepancy. Design: Rates and predictors of conversion were examined in a prospective longitudinal study at a single center. Setting: Among the participants, 46% were recruited from a clinical setting and 54% were recruited directly through community outreach. Participants: One hundred eleven individuals with mild cognitive impairment were followed up longitudinally for an average of 2.4 years (range, 0.5-4.0 years). Main Outcome Measures: Conversion from mild cognitive impairment to dementia. Results: During the follow-up period, 28 individuals progressed to dementia with a mean (SD) time to conversion of 2.19 (0.72) years. The clinic sample had an annual conversion rate of 13%, whereas the community sample had an annual conversion rate of 3%. In a Cox proportional hazards model, clinic recruitment source alone was associated with an increased hazard of incident dementia (hazard ratio = 3.50; 95% confidence interval, 1.31-9.18; P = .01). When other variables were added to the model, only baseline functional impairment as measured by the Clinical Dementia Rating Scale (and no demographic, cognitive, or neuroimaging variables or mild cognitive impairment subtype) accounted for the differences in conversion rates across the 2 cohorts. Conclusions: These findings add to the growing literature to suggest that the degree of functional impairment at baseline is an important predictor of conversion to dementia and may help explain differences in findings between epidemiological and clinic-based studies.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1151-1157 |
| Number of pages | 7 |
| Journal | Archives of Neurology |
| Volume | 66 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 2009 |
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ASJC Scopus subject areas
- Clinical Neurology
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Progression of mild cognitive impairment to dementia in clinic- vs community-based cohorts. / Tomaszewski Farias, Sarah E; Mungas, Dan M; Reed, Bruce R; Harvey, Danielle J; DeCarli, Charles.
In: Archives of Neurology, Vol. 66, No. 9, 09.2009, p. 1151-1157.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Progression of mild cognitive impairment to dementia in clinic- vs community-based cohorts
AU - Tomaszewski Farias, Sarah E
AU - Mungas, Dan M
AU - Reed, Bruce R
AU - Harvey, Danielle J
AU - DeCarli, Charles
PY - 2009/9
Y1 - 2009/9
N2 - Background: Mild cognitive impairment is increasingly recognized as an important public health problem associated with increased risk of developing dementia. Annual conversion rates, however, vary across different studies with clinic samples showing higher rates of conversion than community-based samples. Objectives: To establish whether the rates of conversion from mild cognitive impairment to dementia differed according to recruitment source and, if so, to investigate factors that might explain this discrepancy. Design: Rates and predictors of conversion were examined in a prospective longitudinal study at a single center. Setting: Among the participants, 46% were recruited from a clinical setting and 54% were recruited directly through community outreach. Participants: One hundred eleven individuals with mild cognitive impairment were followed up longitudinally for an average of 2.4 years (range, 0.5-4.0 years). Main Outcome Measures: Conversion from mild cognitive impairment to dementia. Results: During the follow-up period, 28 individuals progressed to dementia with a mean (SD) time to conversion of 2.19 (0.72) years. The clinic sample had an annual conversion rate of 13%, whereas the community sample had an annual conversion rate of 3%. In a Cox proportional hazards model, clinic recruitment source alone was associated with an increased hazard of incident dementia (hazard ratio = 3.50; 95% confidence interval, 1.31-9.18; P = .01). When other variables were added to the model, only baseline functional impairment as measured by the Clinical Dementia Rating Scale (and no demographic, cognitive, or neuroimaging variables or mild cognitive impairment subtype) accounted for the differences in conversion rates across the 2 cohorts. Conclusions: These findings add to the growing literature to suggest that the degree of functional impairment at baseline is an important predictor of conversion to dementia and may help explain differences in findings between epidemiological and clinic-based studies.
AB - Background: Mild cognitive impairment is increasingly recognized as an important public health problem associated with increased risk of developing dementia. Annual conversion rates, however, vary across different studies with clinic samples showing higher rates of conversion than community-based samples. Objectives: To establish whether the rates of conversion from mild cognitive impairment to dementia differed according to recruitment source and, if so, to investigate factors that might explain this discrepancy. Design: Rates and predictors of conversion were examined in a prospective longitudinal study at a single center. Setting: Among the participants, 46% were recruited from a clinical setting and 54% were recruited directly through community outreach. Participants: One hundred eleven individuals with mild cognitive impairment were followed up longitudinally for an average of 2.4 years (range, 0.5-4.0 years). Main Outcome Measures: Conversion from mild cognitive impairment to dementia. Results: During the follow-up period, 28 individuals progressed to dementia with a mean (SD) time to conversion of 2.19 (0.72) years. The clinic sample had an annual conversion rate of 13%, whereas the community sample had an annual conversion rate of 3%. In a Cox proportional hazards model, clinic recruitment source alone was associated with an increased hazard of incident dementia (hazard ratio = 3.50; 95% confidence interval, 1.31-9.18; P = .01). When other variables were added to the model, only baseline functional impairment as measured by the Clinical Dementia Rating Scale (and no demographic, cognitive, or neuroimaging variables or mild cognitive impairment subtype) accounted for the differences in conversion rates across the 2 cohorts. Conclusions: These findings add to the growing literature to suggest that the degree of functional impairment at baseline is an important predictor of conversion to dementia and may help explain differences in findings between epidemiological and clinic-based studies.
UR - http://www.scopus.com/inward/record.url?scp=70349094526&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70349094526&partnerID=8YFLogxK
U2 - 10.1001/archneurol.2009.106
DO - 10.1001/archneurol.2009.106
M3 - Article
C2 - 19752306
AN - SCOPUS:70349094526
VL - 66
SP - 1151
EP - 1157
JO - Archives of Neurology
JF - Archives of Neurology
SN - 0003-9942
IS - 9
ER -