Artikel
The assessment of changes in cognitive functioning in the elderly: Age- and education-specific Reliable Change Indices (RCIs) for the SIDAM. Results of the German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe)
Suche in Medline nach
Autoren
Veröffentlicht: | 20. September 2011 |
---|
Gliederung
Text
Background/Aims: The diagnostic criteria for dementia include reliable evidence of deterioration in cognitive functioning over time in objective cognitive tasks. The Structured Interview for the Diagnosis of Dementia of the Alzheimer Type, Multi-infarct Dementia and Dementia of other Etiology according to DSM-III-R, DSM-IV and ICD-10 (SIDAM) represents a commonly used neuropsychological instrument to determine cognitive status in mild cognitive impairment (MCI) and dementia patients. Specific normative data for changes adjusted for confounding socio-demographic factors (e.g. age and education) in cognitive function that normally occur in cognitively healthy individuals is required to interpret changes in SIDAM test scores.
Methods: A sample of 1,090 cognitively healthy individuals participating in the German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe Study), aged 75 years and older, was assessed four times at 1.5 year intervals over a period of approximately 4.6 years using the SIDAM. Age- and education-specific Reliable Change Indices (RCIs) were computed for a 90% confidence interval.
Results: Across different age and education subgroups, changes from at least 3 to 5 points indicated significant (i.e. reliable) changes in SIDAM test scores at the 90% confidence level. Furthermore, a demonstration how to calculate age- and education-specific RCIs for individual patients is provided.
Conclusion: This study provides age- and education-specific reference values for the SIDAM based upon RCI methods for the interpretation of cognitive changes in older age groups. RCI methods accounting for probable measurement error, practice effects, normal age-related cognitive decline and regression to the mean contribute substantially to the interpretation of changes in SIDAM test scores.