16 - Psychometric issues in the clinical assessment of memory in aging and neurodegenerative disease

Summary

INTRODUCTION

The psychometric issues pertaining to the assessment of memory in elderly persons concern the reliability, validity and normative data available for memory tests. This chapter first discusses patient factors that influence the reliability and validity of memory evaluations and then describes the psychometric properties of memory assessment devices commonly used with the elderly. Methods for estimating premorbid memory abilities and detecting possible changes in memory functions are briefly presented.

It is known that older individuals are more likely than the general population to experience visual and auditory deficits and to be more susceptible to fatigue that may impede the evaluation process. To reduce fatigue, frequent breaks should be taken, testing may need to be conducted over several days and/or abbreviated versions of memory tests may need to be considered. Sensory deficits associated with advancing age also need to be considered.

SENSORYPERCEPTUAL FACTORS INFLUENCING MEMORY EVALUATIONS

Visual functions

Visual efficiency tends to decline with advancing age. It has been estimated that 91% of the severely visually impaired are over the age of 45 years and that 68% of the severely visually impaired are 65 years of age and older (Shindell 1989). Although it is good practice to have examinees who wear glasses bring them to the testing session, wearing glasses does not necessarily ensure adequate visual acuity. It is essential that the examiner determine whether each client's vision is sufficient to allow for valid test administration.