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ObjectiveThe objective of this study is to determine whether differential item functioning (DIF) due to cognitive status impacted three depressive symptoms measures commonly used with older adults.MethodsDifferential item functioning in depressive symptoms was assessed among participants (N = 3558) taking part in four longitudinal studies of cognitive aging, using the Geriatric Depression Scale, the Montgomery-Åsberg Depression Rating Scale, and the Center for Epidemiologic Studies Depression Scale. Participants were grouped by cognitive status using a general cognitive performance score derived from each study's neuropsychological battery and linked to a national average using a population-based survey representative of the US population. The Clinical Dementia Rating score was used as an alternate grouping variable in three of the studies.ResultsAlthough statistically significant DIF based on cognitive status was found for some depressive symptom items (e.g., items related to memory complaints, appetite loss, lack of energy, and mood), the effect of item bias on the total score for each scale was negligible.ConclusionsThe depressive symptoms scales in these four studies measured depression in the same way, regardless of cognitive status. This may reduce concerns about using these depression measures in cognitive aging research, as relationships between depression and cognitive decline are unlikely to have been due to item bias, at least in the ways that were measured in the datasets we considered.

Objective: To develop a validated, caregiver-based measurement scale to assess sexual changes across several domains in a sample of 86 patients with penetrating traumatic brain injury (TBI) and 65 patients with neurodegeneration due to frontotemporal dementia and corticobasal syndrome. Methods: A new measure, the Sexual Symptoms in Neurological Illness and Injury Questionnaire (SNIQ), was constructed. Dimensionality, monotonicity, item discrimination power, and scalability were evaluated using nonparametric Mokken item response theory (IRT) methodology. Results: Three primary domains were established. The domains presented with sufficient reliability (rho.70 to.80), while meeting the Mokken IRT criteria of medium scalability. The domains were labeled ‘Prosocial sexual behaviour’ (H = .42), ‘Sexual interest’ (H = .50), and ‘Inappropriate sexual behaviour’ (H = .41). A fourth dimension emerged, ‘Detachment’ (H = .47), but with very few items. Conclusions: Construct validity was established for groups of items pertaining to three unique aspects of sexuality. These findings support further use of the SNIQ in assessing and researching sexual behaviours in patients with dementia and brain injury. [ABSTRACT FROM AUTHOR]

Background: Decrements in instrumental activities (IADL) have been observed in the prodromal phase of dementia. Given the long predementia stage in neurodegenerative diseases, it has been proposed that subtle functional changes may precede clinical IADL impairment. Incorporating more challenging advanced ADLs (eg, volunteer work) into the assessment process may increase the sensitivity of functional measures, thus expanding the window for monitoring or interventions.Methods: Longitudinal cohort study was used (follow-ups, 18-24 month), with subjects aged 60 and older (n = 3,635). To elucidate the relationship between cognitive ability and functional status we employed an IADL scale with an extended range (ADL-extended; includes IADL but also more challenging advanced ADLs) that meets item response theory properties of dimensionality, monotonicity, and item hierarchy. Procedures involved (a) a dynamic change model employed to inspect the temporal relationship between ADL-extended and cognitive status and (b) Cox proportional hazards to assess the risk of incident dementia based on ADL-extended scores.Results: Growth curve modeling: baseline ADL-extended was significantly associated with all four cognitive domains investigated. Worse baseline ADL-extended was associated with more rapid declines in speed/executive function, and worse baseline memory was associated with more rapid declines in ADL-extended; a concurrent association was found for language and ADL-extended. Cox model: the risk of dementia was decreased for each additional ADL-extended item endorsed (hazard ratio [HR], 0.85; 95% confidence interval = 0.81-0.90).Conclusions: An increased risk of dementia could be observed in the ADL-extended items, which reflects an area of the functional continuum beyond IADL competencies. [ABSTRACT FROM AUTHOR]

Age is the strongest risk factor for physical disability and Alzheimer's disease (AD) and related dementias. As such, other aging-related risk factors are also shared by these two health conditions. However, clinical geriatrics and gerontology research has included cognition and depression in models of physical disability, with less attention to the pathophysiology of neurodegenerative disease. Similarly, AD research generally incorporates limited, if any, measures of physical function and mobility, and therefore often fails to consider the relevance of functional limitations in neurodegeneration. Accumulating evidence suggests that common pathways lead to physical disability and cognitive impairment, which jointly contribute to the aging phenotype. Collaborations between researchers focusing on the brain or body will be critical to developing, refining, and testing research paradigms emerging from a better understanding of the aging process and the interacting pathways contributing to both physical and cognitive disability. The National Institute of Aging sponsored a workshop to bring together the Claude D. Pepper Older Americans Independence Center and AD Center programs to explore areas of synergies between the research concerns of the two programs. This article summarizes the proceedings of the workshop and presents key gaps and research priorities at the intersection of AD and clinical aging research identified by the workshop participants. [ABSTRACT FROM AUTHOR]

Aims. To demonstrate the principles and application of Mokken scaling. Background. The history and development of Mokken scaling is described, some examples of applications are given, and some recent development of the method are summarised. Design. Secondary analysis of data obtained by cross-sectional survey methods, including self-report and observation. Methods. Data from the Edinburgh Feeding Evaluation in Dementia scale and the Townsend Functional Ability Scale were analysed using the Mokken scaling procedure within the 'R' statistical package. Specifically, invariant item ordering (the extent to which the order of the items in terms of difficulty was the same for all respondents whatever their total scale score) was studied. Results. The Edinburgh Feeding Evaluation in Dementia scale and the Townsend Functional Ability Scale showed no violations of invariant item ordering, although only the Townsend Functional Ability Scale showed a medium accuracy. Conclusion. Mokken scaling is an established method for item response theory analysis with wide application in the social sciences. It provides psychometricians with an additional tool in the development of questionnaires and in the study of individuals and their responses to latent traits. Specifically, with regard to the analyses conducted in this study, the Edinburgh Feeding Evaluation in Dementia scale requires further development and study across different levels of severity of dementia and feeding difficulty. Relevance to clinical practice. Good scales are required for assessment in clinical practice and the present paper shows how a relatively recently developed method for analysing Mokken scales can contribute to this. The two scales used as examples for analysis are highly clinically relevant. [ABSTRACT FROM AUTHOR]