Multicenter evaluation of new instruments for Alzheimer's disease clinical trials: summary of results. The Alzheimer's Disease Cooperative Study.
ABSTRACT The Instrument Development Project of the Alzheimer's Disease Cooperative Study (ADCS) evaluated new assessments in five domains: (a) cognitive function; (b) clinical global change; (c) activities of daily living; (d) behavioral symptoms, and (e) cognition in severely impaired patients. These new instruments demonstrate excellent discrimination between normal controls and patient groups and show adequate validity and reliability. Stability of measurement and sensitivity to longitudinal change were also demonstrated in each of these areas. Examination of several domain-specific questions also contributed new information on the measurement of cognitive function with different subtasks across AD severity levels, the stability of clinical ratings of global change, and the applicability of behavioral assessment across severity levels. The success of this project enhances the state of the art in the measurement of efficacy in AD clinical trials and also provides a basis for future research on improving AD outcome measures.
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ABSTRACT: The Alzheimer’s Disease Assessment Scale – Cognitive Subscale (ADAS-Cog) has become the de facto gold standard for assessing the efficacy of anti-dementia treatments. However, manual administration of the ADAS-Cog is subject to procedural inconsistencies, including scoring and transcription errors, which can introduce unwanted variance and compromise data quality within and across sites and trials. To address such concerns, a computerized version was developed that integrates, rather than replaces, the examiner, standardizes administration, and uses electronic data capture at the point of patient contact. The examiner can control administration and pacing, pause or repeat digitized instructions, score verbal report and overt behavioral performance, and freely interact with the subject. To conduct psychometric comparisons of traditional, paper-based administration of the standard ADAS-Cog (sADAS) with examiner- assisted administration of the computerized ADAS-Cog (cADAS). Eighty-eight patients (39M; 49F) with mild to moderate Alzheimer’s disease were tested on three occasions with each version over a period of one year with one month between paired visits. Intraclass Correlation Coefficients (ICC) comparisons between sADAS and cADAS were significant for total score (ICC=0.96) and all subscores (ICCs ranged 0.78-0.93), with no significant differences on paired t-tests. The mean ICCs across cADAS scores for test-retest reliability for short-term (mean ICC=0.96) and long-term (mean ICC=0.91) comparisons were significantly higher than across sADAS scores (mean ICCs were 0.87 and 0.84, respectively). These results indicate that examiner-assisted, computerized administration is equivalent to traditional, paper-based administration, and shows significantly greater test-retest reliability.Current Alzheimer research 02/2011; 8(3):323-8. DOI:10.2174/1567211213146222050 · 3.80 Impact Factor
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ABSTRACT: Abstract Diagnosis of dementia in adults with intellectual disabilities requires documentation of clinically significant declines in memory and other cognitive skills, as well as changes in everyday and emotional functioning. To improve diagnostic accuracy in adults with Down syndrome, the authors examined conditions often associated with dementia, as well as tests useful for documentation of decline. Specific aims were to identify psychiatric disorders or medical conditions that increased the odds of a dementia diagnosis; to evaluate the sensitivity and specificity of widely used dementia scales; and to determine which tests, used singly or in combination, most accurately supported the presence of dementia. Participants were 78 adults with Down syndrome. Two methods based on a large test battery and one method based on clinical judgment were used to diagnose dementia. It was found that combinations of tests lead to increased levels of diagnostic sensitivity compared with single tests. When taken in combination with other investigations, our results suggest that assessment for psychiatric disorders, delayed memory decline, adaptive behavior decline, and the presence of seizures would be useful for the diagnosis of dementia and that dementia scales would provide additional useful information. The authors conclude that combinations of tests and scales will be most useful for diagnosing dementia in adults with intellectual disabilities. The authors suggest that further research is needed to promote rapid progress, with studies that focus on common diagnostic methodology, identification of screening instruments, and amounts of decline indicative of dementia.Journal of Policy and Practice in Intellectual Disabilities 02/2005; 2(1):47 - 56. DOI:10.1111/j.1741-1130.2005.00007.x · 0.97 Impact Factor
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ABSTRACT: Alzheimer's disease (AD) is associated with neuropsychologic and neuropsychiatric dysfunction and is a leading cause of disability among the elderly. Impairments in activities of daily living (ADL) contribute significantly to the disability reported among patients with AD and diminish quality of life for patients and their families. ADL assessment represents an important component of the diagnosis, tracking, and management of AD. Further, an understanding of the determinants of ADL dysfunction is critical for the early identification of individuals at risk for functional disability and for improved patient care. This manuscript reviews methods for assessing ADL in patients with AD and summarizes the available literature on the neuropsychologic and neuropsychiatric correlates of functional impairment in AD. The emerging role of frontal system dysfunction as an important determinant of ADL impairment is discussed, and recommendations for clinical practice and future research are provided.Current Psychiatry Reports 03/2004; 6(1):20-4. DOI:10.1007/s11920-004-0033-9 · 3.05 Impact Factor