Ylva Cedervall

Objective: The purpose of the study was to establish reference values for the Uppsala-Dalarna Dementia and Gait (UDDGait) Timed “Up & Go” dual-task (TUGdt) test variables in cognitively healthy adults and to assess these variables’ test–retest reliability. Methods: For reference values, 166 participants were recruited with approximately equal numbers and proportions of women and men in the age groups 50 to 59, 60 to 69, 70 to 79, and 80+ years (mean age = 70 years, age range = 50–91 years, 51% women). For reliability testing, 43 individuals (mean age = 69 years, age range = 50–89 years, 51% women) were recruited. Two dt tests were carried out: TUGdt naming animals and TUGdt months backward, representing 8 test variables: time scores, costs (the relative difference between single-task and dt time scores), “number of animals,” “number of months,” “animals/10 seconds ,” and “months/10 seconds .” Reference ranges for the variables were established by quantile regression in age- and sex-specific groups. For reliability, intraclass correlation coefficients (ICCs), standard error of measurement, minimal detectable change, and Bland–Altman plots were used. Results: Reference values for the TUGdt test variables are presented for the 2.5th and 97.5th percentiles. The reliability of TUGdt time scores was excellent (ICCs between 0.85 and 0.86). “Number of animals” and “animals/10 seconds” as well as “months/10 seconds” showed fair to good levels of reliability (ICCs between 0.45 and 0.58), whereas the reliability for both cost measures and “number of months” was poor (ICCs between 0.34 and 0.39). Conclusion: Normative reference values, potentially useful for clinical and research purposes, were presented in 4 age- and sex-specific groups from 50 years and older. Reliability for the test variables varied between poor and excellent, the lower estimates partly explained by some variables being the ratio of 2 other variables. In UDDGait, TUGdt tests are intended for diagnostic and predictive purposes, for which these tests are promising and require further investigations. Impact: Normative reference values and test–retest reliability results for the UDDGait TUGdt test variables were presented. These results should be useful for both clinical and research purposes.

The aim of this study was to investigate whether Timed Up-and-Go (TUG) dual-task (TUGdt) tests predict dementia incidence among patients with subjective or mild cognitive impairment (SCI; MCI). Other study objectives were to determine whether TUGdt improves dementia prediction compared to a) demographic characteristics and standard cognitive tests alone; and b) TUG and Verbal Fluency performed separately. Patients (n = 172, age range 39–91 years, 78 women) with SCI or MCI performed TUGdt tests, including 1) naming animals and 2) reciting months backwards, and clinical cognitive tests at baseline. Diagnoses were identified at follow-up after 2.5 years. Logistic regression was used to predict dementia incidence, receiver operating characteristic (ROC) curves and c-statistics for predictive capacity. Analyses were stratified by age and gender. At follow-up, 51 patients had developed dementia. The TUGdt result “animals/10 s” was associated with dementia incidence (standardized odds ratio (OR) = 4.06, 95% confidence interval (CI) 2.28–7.23, p < 0.001), more so among patients under the median age of 72 years (standardized OR = 19.4, 95% CI 3.53–106.17, p < 0.001). TUGdt “animals/10 s” improved dementia prediction compared to demographic characteristics and standard tests alone (c-statistics 0.88 to 0.94) and single-task tests (c-statistics 0.86 to 0.89), but only in the younger patient group. TUGdt has the potential to become a useful tool for dementia prediction.

New methods to screen for and identify early-stage dementia disorders are highly sought after. The purpose of this pilot study is to develop a study protocol for a dual-task test aimed at aiding the early detection of dementia disorders. We used the Timed Up-and-Go (TUG) test, which is a mobility task involving starting in a sitting position, standing up, walking three meters to cross a line on the floor, turning around, walking back and sitting down again. We combined TUG with the verbal task of naming different animals. Pilot study participants were 43 individuals with and without established dementia diagnoses who attended a clinic for memory assessment. Video-recorded test performances were systematically analysed. Deviant test performances concerning the interplay between test administration and participants’ responses to the assessment instructions were revealed and led to refinements being made to the final study protocol. Exploration of the dual-task test outcome measures in a sub-sample of 22 persons, ten with and twelve without dementia, indicated that step-length and number of named animals after the turning point of the dual-task test might constitute appropriate measures for examining this kind of sample. We concluded that the refined study protocol is feasible for testing individuals undergoing initial memory assessments and healthy controls. Follow-up studies with larger samples are being carried out and will bring new knowledge to this area of research. It may also provide an opportunity for further studies exploring possibilities for broad clinical implementation.

Objectives: To contribute to furthering the understanding of how people with mild Alzheimer's disease (AD) reason about physical activity as part of everyday life, with a specific focus on the meanings attached to such activity. Method: In-depth interviews were conducted with 14 individuals with mild AD. Qualitative content analysis was used to interpret the data. Results: The analysis revealed three sub-themes reflecting interrelated perspectives on how people with mild AD reason about physical activity: (1) striving to be physically active, mirrors the concrete approaches used for handling the consequences of having AD in relation to being active; (2) perceptions of physical activity, reflect how their thoughts and beliefs regarding written and tacit norms encouraged them to remain physically active, and (3) physical activity as a means to well-being, alludes to feelings and emotions related to the performance of physical activity. Interpretation of the underlying patterns in these sub-themes revealed one overarching theme: Physical activity as a means to selfhood maintenance, which suggests that physical activity can help to shift the focus from the dementia diagnosis (i.e. ill health) to a more healthy and able self. Conclusion: The findings suggest that physical activity, apart from maintaining body functions, can be a way to sustain well-being and selfhood in mild AD. This aspect of physical activity is important to consider in research, policy and practice when addressing the needs of people with dementia.

The longitudinal influences on physical capacity and habitual aerobic activity level in the early stages of Alzheimer’s disease (AD) are unclear. Therefore, changes in physical capacity and aerobic activity level were evaluated. Twenty-five individuals with AD were assessed annually for 2 years, by 10-m walk test, 6-minute walk test, and timed up-and-go (TUG) single/dual tasks. Habitual aerobic activity was assessed by diary registrations. The AD group showed a lower physical capacity than controls at baseline but comparable levels of aerobic activity. During the follow-up period, physical capacity declined in the AD group, but the aerobic activity levels changed only marginally. Our results show that in the early stages of AD, people are capable of maintaining health-promoting aerobic activity levels, despite a decline in their physical capacity. Additionally, it appears that cognitive dysfunction contributes to an impaired physical capacity. The TUG tasks might, therefore, be useful for detecting early signs of cognitive impairment.