Kara S. Schmidt, PhD
The DRS-2 is a widely used instrument for the assessment of neurocognitive status. Because it is appropriate for use by professionals across multiple disciplines (e.g. neuropsychology, psychiatry, neurology, gerontology), an equivalent form was needed, and subsequently, the DRS-2: Alternate Form was developed.
The DRS-2: Alternate Form reduces the practice effects that occur with serial administrations of the original DRS-2. This issue is particularly important in the assessment of older adults (ages 55-89 years and older) with neuropsychiatric illness. Accurate documentation of cognitive changes is crucial to arrive at a precise diagnosis. Often, it is necessary to administer mental status measures multiple times over a relatively brief period. Thus, having two DRS-2 forms available allows for a better characterisation of declining cognitive status and an improvement in the evaluation of treatment efficacy.
The DRS-2: Alternate Form test materials include the Professional Manual Supplement, 1 set of Stimulus Cards, Scoring Booklets, and Profile Forms. The Professional Manual Supplement is an adjunct to the original DRS-2 Professional Manual, which provides all normative tables and data as well as interpretive guidelines for both forms of the DRS-2. The item content in the newly designed DRS-2: Alternate Form Scoring Booklet and the stimuli in the DRS-2: Alternate Form Stimulus Cards are structured to mirror their respective original forms. The DRS-2:IR software also has been updated to include the use of either or both forms.
Reliability and Equivalency Studies
Test-retest reliability of the DRS-2: Alternate Form is strong. In addition, alternate form reliability between the original DRS-2 and the DRS-2: Alternate Form is strong, with a correlation coefficient of .82 for the Total Score, and correlation coefficients ranging from .66 to .80 for the subscales. Several other studies, including a generalisability and equipercentile equating, were utilised to determine the equivalency between the two forms.
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