Serial cognitive assessment is used in clinical practice, performing below the cut-point on a screening measure TRIALS

Full list of author information is available at the end of the articleclinical trials, and longitudinal studies of aging and de-mentia to track cognitive fluctuations over time and to identify clinically significant declines in performance sug-gestive of mild cognitive impairment (MCI) or dementia. Screening measures with specific cut-points reflecting probable cognitive impairment are also frequently used as brief, first-line measures of gross cognitive functioning in may be referred for more extensive diagnostic evaluation. Research participants may be screened into or out of stud-ies based upon whether their performance lies above or below the cut-point of the measure. When cognitive instruments are used repeatedly, it is imperative to know not only the sensitivity, specificity, positive predictive value, and negative predictive value of the instruments, but also their behavior over time. Practice effects (PE) represent one aspect of that be-havior. PE are distinct from random fluctuations in per