The Assessment of Changes in Cognitive Functioning in the Elderly: Age- and Education-Specific Reliable Change Indices for the SIDAM

Abstract

Background/Aims: The diagnostic criteria for dementia include reliable evidence of cognitive deterioration over time measured by cognitive tests. 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) is a neuropsychological instrument to determine cognitive status in patients with mild cognitive impairment (MCI) and dementia. Normative data for changes in cognitive functioning that normally occur in cognitively healthy individuals are 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) aged 75 years and older was assessed four times at 1.5-year intervals over a period of 4.5 years using the SIDAM. Age- and education-specific reliable change indices (RCIs) accounting for probable measurement error and practice effects were computed for a 90% confidence interval. Results: Across different age and education subgroups, changes from at least 3–5 points indicated significant (i.e. reliable) changes in SIDAM test scores at the 90% confidence level. Conclusion: This study offers age- and education-specific normative data for the SIDAM based upon established RCI methods. The RCI scores provided in this study may help clinicians and researchers to interpret cognitive changes in SIDAM test scores and may contribute to the early detection and diagnosis of MCI and dementia in the elderly.

Normative Data for the Cognitively Intact Oldest-Old: The Framingham Heart Study

“…Indeed, in the current study, there are large educational differences between age bands (e.g., 16–43% of individuals in the oldest-old age bands, where the proportion of women is higher, with less than high school education compared to 3–10% of young-old individuals, where the proportion of women to men is nearly equivalent, with less than high school education), although the interaction reported was not a result of educational differences. Other studies of cognition in the extremely elderly have not found an effect of gender (Coluccia, Gamboz, & Brandimonte, 2011; Davey et al, 2013; Stein et al, 2012). The lack of other effect modifications by gender in the present study is consistent with literature suggesting that gender may not be the most significant contributor to cognition among the oldest-old, though additional evidence about the specific nature of the interaction on these measures is a subject for future study.…”

“…In a sample of HIV+ and HIV− women, Manly and coauthors (2011) found that reading level as defined by the WRAT-III had the strongest relationship to cognitive performance, compared to HIV status, education, and in some cases, age (Manly et al, 2011). However, the majority of studies of cognition in the oldest-old do use education as a marker for premorbid ability and it is often found to be a significant predictor of cognitive performance (Beeri et al, 2006; Coluccia et al, 2011; Davey et al, 2010; Dore et al, 2007; Kenny et al, 2013; Miller et al, 2010; Stein et al, 2012; Welsh-Bohmer et al, 2009), though a study of verbal fluency performance in elderly individuals found no significant differences based on reading ability or education (Ravdin et al, 2003). We do provide age- and education-based normative data in the supplementary materials as we know that clinicians more often have access to years of education than WRAT Reading performance.…”

Emergence of Mild Cognitive Impairment in Late Middle-Aged Adults in the Wisconsin Registry for Alzheimer's Prevention

“…Subsequent analyses will also compare the multiwave approach with other methods of evaluating cognitive change such as a reliable change index approach (e.g., Stein et al, 2012) [55] and analysis of whether practice effects in early waves predict subsequent aMCI status in ways similar to other studies (e.g., Duff et al, 2008) [56] It will also be critical to compare biomarker profiles for the aMCI robust-multiwave vs. cognitively healthy groups and to continue longitudinal follow-up to further assess cognitive trajectories and to establish dementia endpoints. The validity of the current multiwave aMCI classification will be supported if the aMCI group shows neuroimaging and/or CSF profiles consistent with preclinical AD, and ultimately, higher rates of AD.…”

Indicators for Healthy Ageing — A Debate

“…The main instruments used to assess cognitive functions were 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), the Mini-Mental State Examination (MMSE), and the CERAD-NP battery. Within this study, RCI scores were calculated for all three instruments [53,54,55]. The RCI scores were adjusted for the sociodemographic variables of age, gender, and education as these variables showed a significant impact on cognitive test performance.…”