Comparing Dementia Diagnostic Methods Used with People with Intellectual Disabilities
In: Journal of policy and practice in intellectual disabilities: official journal of the International Association for the Scientific Study of Intellectual Disabilities, Band 2, Heft 2, S. 94-115
ISSN: 1741-1130
Abstract Accurate detection of dementia in adults with intellectual disabilities is important for clinical care, program planning, and clinical research. This paper reports on a study that examined two major diagnostic methods that varied in the following ways: (1) the extent to which they relied on clinical judgment; (2) the statistical method used to detect declines; and (3) the sensitivity to declines in functioning. Two methods based on testing were compared with one based on clinical judgment. Data were drawn from annual sequential assessments of 168 adults with intellectual disabilities (78 with Down syndrome and 90 with other etiologies). Agreement between testing and clinical judgment methods was 72–75% depending on testing method used. Clinical judgment produced a higher rate of dementia diagnosis for adults with Down syndrome compared with testing methods, suggesting a possible bias. The authors found that diagnostic criteria were useful both for identifying dementia and for describing its characteristics. Our results suggest that clinical judgment could result in a higher number of adults with Down syndrome diagnosed with dementia than methods based on test batteries. Common results across research studies indicate that combinations of sources of information (interviews/direct testing) would be most useful for dementia diagnosis. Future collaboration across research sites is needed to promote rapid progress in this important area, with emphasis on differential diagnosis.