Abstract
Background: We have previously established the reliability and cross-sectional validity of the SIST-M (Structured Interview and Scoring Tool-Massachusetts Alzheimer's Disease Research Center), a shortened version of an instrument shown to predict progression to Alzheimer disease (AD), even among persons with very mild cognitive impairment (vMCI). Objective: To test the predictive validity of the SIST-M. Methods: Participants were 342 community-dwelling, nondemented older adults in a longitudinal study. Baseline Clinical Dementia Rating (CDR) ratings were determined by either (1) clinician interviews or (2) a previously developed computer algorithm based on 60 questions (of a possible 131) extracted from clinician interviews. We developed age+sex+education-adjusted Cox proportional hazards models using CDR-sum-of-boxes (CDR-SB) as the predictor, where CDR-SB was determined by either a clinician interview or an algorithm; models were run for the full sample (n=342) and among those jointly classified as vMCI using clinician-based and algorithm-based CDR ratings (n=156). We directly compared predictive accuracy using time-dependent receiver operating characteristic (ROC) curves. Results: AD hazard ratios (HRs) were similar for clinician-based and algorithm-based CDR-SB: for a 1-point increment in CDR-SB, the respective HRs [95% confidence interval (CI)] were 3.1 (2.5, 3.9) and 2.8 (2.2, 3.5); among those with vMCI, the respective HRs (95% CI) were 2.2 (1.6, 3.2) and 2.1 (1.5, 3.0). Similarly high predictive accuracy was achieved: the concordance probability (weighted average of the area-under-the-ROC curves) over follow-up was 0.78 versus 0.76 using clinician-based versus algorithm-based CDR-SB. Conclusion: CDR scores based on items from this shortened interview had high predictive ability for AD-comparable to that using a lengthy clinical interview.
Original language | English (US) |
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Pages (from-to) | 225-231 |
Number of pages | 7 |
Journal | Alzheimer disease and associated disorders |
Volume | 26 |
Issue number | 3 |
DOIs | |
State | Published - Jul 2012 |
Keywords
- Alzheimer disease
- CDR
- dementia
- instrument
- mild cognitive impairment
- prediction
- psychometric
- questionnaire
- validity
ASJC Scopus subject areas
- Clinical Psychology
- Gerontology
- Geriatrics and Gerontology
- Psychiatry and Mental health