Facilitating interpretation of cognitive impairment: the development of reliable changes scores for the cognitive measures in the Canadian Longitudinal Study on Aging

Project Summary

The CLSA collects information about the cognitive functioning of English- and French-speaking participants aged 45-85 years at enrolment. The ability to assess whether a person’s performance has changed over time is critical to diagnose mild cognitive impairment or dementia. Assessment of cognitive change over time is complicated, however, by measurement error, which is an unavoidable part of any standardized assessment, and other factors such as improvement in performance due to practice. We will develop reliable change methods for CLSA cognitive measures based on healthy persons who completed the baseline and first follow-up assessments. Reliable change methods allow us to determine if a change in cognition has occurred over time. Developing reliable change methods will allow us to complete additional important analyses, such as determining whether a change in cognitive performance over time is clinically meaningful.