Cognitive Impairment Indicator for the Neuropsychological Test Batteries in the Canadian Longitudinal Study on Aging: Definition and Evidence for Validity

Abstract

BACKGROUND: Prevalence of overall cognitive impairment based on each participant’s performance across a neuropsychological battery is challenging; consequently, we define and validate a dichotomous cognitive impairment/no cognitive indicator (CII) using a neuropsychological battery administered in a population-based study. This CII approximates the clinical practice of interpretation across a neuropsychological battery and can be applied to any neuropsychological dataset. METHODS: Using data from participants aged 45-85 in the Canadian Longitudinal study on Aging receiving a telephone-administered neuropsychological battery (Tracking, N = 21,241) or a longer in-person battery (Comprehensive, N = 30,097), impairment was determined for each neuropsychological test based on comparison with normative data. We adjusted for the joint probability of abnormally low scores on multiple neuropsychological tests using baserates of low scores demonstrated in the normative samples, and created a dichotomous CII (i.e., cognitive impairment vs no cognitive impairment). Convergent and discriminant validity of the CII were assessed with logistic regression analyses.RESULTS: Using the CII, the prevalence of cognitive impairment was 4.3% in the Tracking and 5.0% in the Comprehensive cohorts. The CII demonstrated strong convergent and discriminant validity. CONCLUSIONS: The algorithm for the CII is a feasible method to identify participants who demonstrate cognitive impairment on a battery of tests. These methods can be applied in other epidemiological studies that use neuropsychological batteries.

Prioritizing determinants of cognitive function in healthy middle-aged and older adults: insights from a machine learning regression approach in the Canadian longitudinal study on aging

“…The outcome for this study was cognitive function measured by a latent construct score for overall cognition developed by the CLSA (18). The overall cognition latent construct score is based on scores achieved in eight cognitive tests administered as a neuropsychological battery to study participants by CLSA staff.…”

The association between shift work exposure and cognitive impairment among middle-aged and older adults: Results from the Canadian Longitudinal Study on Aging (CLSA)

“…Our study had several strengths. A major strength of this study is that, to our knowledge, it is the first study to investigate the associations between different types of SW exposure (night and rotating shift), and cognitive impairment based on Canadian standards, which means that cognitive impairment was identified after comparisons with neuro-healthy normative data [ 48 , 49 ]. All cognitive test scores are normalized for the participant’s age, sex, education level and language of test administration (English and French) [ 48 ].…”

“…A binary-valued variable (yes/no) that indicates the participant’s overall cognitive performance on the basis of four individual cognitive impairment variables and can only be calculated when all four are available i.e. REYI, REYII, AF2, and MAT [ 48 , 49 ]. The presence of two or more individual impaired scores are suggestive of overall cognitive impairment and coded as ‘yes’, whereas zero or one impaired score is suggestive of ‘no’ impairment overall [ 48 , 49 ].…”

“…REYI, REYII, AF2, and MAT [ 48 , 49 ]. The presence of two or more individual impaired scores are suggestive of overall cognitive impairment and coded as ‘yes’, whereas zero or one impaired score is suggestive of ‘no’ impairment overall [ 48 , 49 ].…”

“…However, other studies [66][67][68], have discovered higher rates (10.8%, 7%, 8.7%) of cognitive impairment. A major factor that may have influenced these differences is the CLSA study design, which included only persons without overt cognitive impairment at baseline [49].…”