Age-Correction of Test Scores Reduces the Validity of Mild Cognitive Impairment in Predicting Progression to Dementia

Abstract

ObjectivesA phase of mild cognitive impairment (MCI) precedes most forms of neurodegenerative dementia. Many definitions of MCI recommend the use of test norms to diagnose cognitive impairment. It is, however, unclear whether the use of norms actually improves the detection of individuals at risk of dementia. Therefore, the effects of age- and education-norms on the validity of test scores in predicting progression to dementia were investigated.MethodsBaseline cognitive test scores (Syndrome Short Test) of dementia-free participants aged ≥65 were used to predict progression to dementia within three years. Participants were comprehensively examined one, two, and three years after baseline. Test scores were calculated with correction for (1) age and education, (2) education only, (3) age only and (4) without correction. Predictive validity was estimated with Cox proportional hazard regressions. Areas under the curve (AUCs) were calculated for the one-, two-, and three-year intervals.Results82 (15.3%) of initially 537 participants, developed dementia. Model coefficients, hazard ratios, and AUCs of all scores were significant (p<0.001). Predictive validity was the lowest with age-corrected scores (−2 log likelihood = 840.90, model fit χ2 (1) = 144.27, HR = 1.33, AUCs between 0.73 and 0.87) and the highest with education-corrected scores (−2 log likelihood = 815.80, model fit χ2 (1) = 171.16, HR = 1.34, AUCs between 0.85 and 0.88).ConclusionThe predictive validity of test scores is markedly reduced by age-correction. Therefore, definitions of MCI should not recommend the use of age-norms in order to improve the detection of individuals at risk of dementia.

Moderating effect of cognitive reserve on the association between grey matter atrophy and memory varies with age in older adults

“…In conclusion, this study was able to suggest one possible reason why the protective role of CR in normal cognitive aging has been elusive. Although age and educational attainment are formally used as demographic norms to ascertain whether an individual's cognitive function has significantly declined or not, such norm‐based decision criteria and brain structural markers seem to have complications that cannot be straightforwardly adjusted with stratified norms . The results suggest that age and CR factors not only affect the neuropsychological function in an independent fashion but also simultaneously interact with a neuropathological marker.…”

The prevalence and progression of mild cognitive impairment among clinic and community populations: a systematic review and meta-analysis

“…The high heterogeneity of each outcome may potentially impair the statistical power of our meta-analysis, which was amended after biased publications are excluded resulting in a more precise conclusion. However, this NOTE: Weights are from random effects analysis Overall (I = 95.9%, p < 0.001) Alexopoulos, 2006Annerbo, 2006Visser, 2006 Subtotal (I = 95.3%, p < 0.001) Cervellati, 2014Aretouli, 2013Bombois, 2008Ganguli, 2004Heun, 2006ID Hansson, 2009 Van der Mussele, 2014 Lopez, 2007Solfrizzi, 2004Clinic Aggarwal, 2005Ritchie, 2001 Study Ravaglia, 2006Nordlund, 2010 Subtotal (I = 94.3%, p < 0.001) Busse, 2006Solfrizzi, 2007Community Bonanni, 2015Tschanz, 2006Dickerson, 2007Cova, 2016Zanetti, 2006Unverzagt, 2001Gabr yelewicz, 2007Hessler, 2014 heterogeneity may still persist, since there existed an incompleteness of included data and disparity of MCI definitions, so a more unified evaluation system is required.…”

Study of the Influence of Age in 18F-FDG PET Images Using a Data-Driven Approach and Its Evaluation in Alzheimer’s Disease

“…More specifically, in [ 26 ], the authors applied an age-correction criterion [ 27 ] based on the results of the Montreal Cognitive Assessment (MoCA) according to the circumstance that predetermined the age range of the patient. Similar criteria can be found in [ 28 ]. Although these corrections were not based directly on brain images, the line of thought was illuminating.…”