Cluster analysis of functional independence in community-dwelling older people.

BACKGROUND: The concept of Functional Independence (FI), defined as 'functioning physically safe and independent from other persons, within one's context", plays an important role in maintaining the functional ability to enable well-being in older age. FI is a dynamic and complex concept covering four clinical outcomes: physical capacity, empowerment, coping flexibility, and health literacy. As the level of FI differs widely between older adults, healthcare professionals must gain insight into how to best support older people in maintaining their level of FI in a personalized manner. Insight into subgroups of FI could be a first step in providing personalized support This study aims to identify clinically relevant, distinct subgroups of FI in Dutch community-dwelling older people and subsequently describe them according to individual characteristics. RESULTS: One hundred fifty-three community-dwelling older persons were included for participation. Cluster analysis identified four distinctive clusters: (1) Performers - Well-informed; this subgroup is physically strong, well-informed and educated, independent, non-falling, with limited reflective coping style. (2) Performers - Achievers: physically strong people with a limited coping style and health literacy level. (3) The reliant- Good Coper representing physically somewhat limited people with sufficient coping styles who receive professional help. (4) The reliant - Receivers: physically limited people with insufficient coping styles who receive professional help. These subgroups showed significant differences in demographic characteristics and clinical FI outcomes. CONCLUSIONS: Community-dwelling older persons can be allocated to four distinct and clinically relevant subgroups based on their level of FI. This subgrouping provides insight into the complex holistic concept of FI by pointing out for each subgroup which FI domain is affected. This way, it helps to better target interventions to prevent the decline of FI in the community-dwelling older population.

Discriminative validity of the Core outcome set functional independence in a population of older adults.

BACKGROUND: Clinicians are currently challenged to support older adults to maintain a certain level of Functional Independence (FI). FI is defined as "functioning physically safely and independent from another person, within one's own context". A Core Outcome Set was developed to measure FI. The purpose of this study was to assess discriminative validity of the Core Outcome Set FI (COSFI) in a population of Dutch older adults (≥ 65 years) with different levels of FI. Secondary objective was to assess to what extent the underlying domains 'coping', 'empowerment' and 'health literacy' contribute to the COSFI in addition to the domain 'physical capacity'. METHODS: A population of 200 community-dwelling older adults and older adults living in residential care facilities were evaluated by the COSFI. The COSFI contains measurements on the four domains of FI: physical capacity, coping, empowerment and health literacy. In line with the COSMIN Study Design checklist for Patient-reported outcome measurement instruments, predefined hypotheses regarding prediction accuracy and differences between three subgroups of FI were tested. Testing included ordinal logistic regression analysis, with main outcome prediction accuracy of the COSFI on a proxy indicator for FI. RESULTS: Overall, the prediction accuracy of the COSFI was 68%. For older adults living at home and depending on help in (i)ADL, prediction accuracy was 58%. 60% of the preset hypotheses were confirmed. Only physical capacity measured with Short Physical Performance Battery was significantly associated with group membership. Adding health literacy with coping or empowerment to a model with physical capacity improved the model significantly (p < 0.01). CONCLUSIONS: The current composition of the COSFI, did not yet meet the COSMIN criteria for discriminative validity. However, with some adjustments, the COSFI potentially becomes a valuable instrument for clinical practice. Context-related factors, like the presence of a spouse, also may be a determining factor in this population. It is recommended to include context-related factors in further research on determining FI in subgroups of older people.

Determinants of Dual-Task Training Effect Size in Parkinson Disease: Who Will Benefit Most?

BACKGROUND AND PURPOSE: Dual-task interventions show positive effects in people with Parkinson disease (PD), but it remains unclear which factors determine the size of these benefits. As a secondary analysis of the DUALITY trial, the aim of this study was to assess the determinants of the effect size after 2 types of dual-task practice. METHODS: We randomly allocated 121 participants with PD to receive either integrated or consecutive dual-task training. Dual-task walking performance was assessed during (i) a backward digit span task (digit), (ii) an auditory Stroop task (Stroop), and (iii) a functional mobile phone task. Baseline descriptive, motor, and cognitive variables were correlated with the change in dual-task gait velocity after the intervention. Factors correlated with the change in dual-task gait velocity postintervention (P < 0.20) were entered into a stepwise forward multiple linear regression model. RESULTS: Lower dual-task gait velocity and higher cognitive capacity (Scales for Outcomes in Parkinson's Disease-Cognition [ScopaCog]) at baseline were related to larger improvements in dual-task gait velocity after both integrated and consecutive dual-task training for all 3 tasks (ß[gait] = -0.45, ß[ScopaCog] = 0.34, R = 0.23, P < 0.001, for digit; ß[gait] = -0.52, ß[ScopaCog] = 0.29, R = 0.26, P < 0.001, for Stroop; and ß[gait] = -0.40, ß[ScopaCog] = 0.30, R = 0.18, P < 0.001, for mobile phone task). DISCUSSION AND CONCLUSIONS: Participants with PD who showed a slow dual-task gait velocity and good cognitive functioning at baseline benefited most from the dual-task training, irrespective of the type of training and type of dual-task outcome.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A242).

Training dual tasks together or apart in Parkinson's disease: Results from the DUALITY trial.

BACKGROUND AND OBJECTIVES: Many controversies surround the usefulness of dual-task training in Parkinson's disease (PD). This study (1) compared the efficacy of two different dual-task training programs for improving dual-task gait and (2) assessed the possible fall risk of such training. METHODS: Patients (N = 121) with a diagnosis of PD (aged 65.93 [±9.22] years, Hoehn and Yahr stage II-III on-medication) were randomized to (1) a consecutive group in which gait and cognitive tasks were trained separately or (2) an integrated group in which gait and cognitive tasks were trained simultaneously. Both interventions involved 6 weeks of at-home physiotherapist-led training. Two baseline tests were performed as a 6-week control period before training. Posttests were performed immediately after training and at 12-week follow-up. Dual-task gait was assessed during trained and untrained secondary tasks to assess consolidation of learning. Fall risk was determined by a weekly telephone call for 24 weeks. RESULTS: No significant time by group interactions were found, suggesting that both training modes had a similar effect on dual-task gait. Immediately after training, and not after the control period, significant improvements (P < .001) in dual-task gait velocity were found in all trained and untrained dual tasks. Improvements ranged between 7.75% and 13.44% when compared with baseline values and were retained at 12-week follow-up. No significant change in fall risk occurred in both study arms (P = .84). CONCLUSIONS: Consecutive and integrated dual-task training led to similar and sustained improvements in dual-task gait velocity without increasing fall risk. These novel findings support adoption of dual-task training in clinical practice. © 2017 International Parkinson and Movement Disorder Society.

Test-Retest Reliability of Dual-Task Outcome Measures in People With Parkinson Disease.

BACKGROUND: Dual-task (DT) training is gaining ground as a physical therapy intervention in people with Parkinson disease (PD). Future studies evaluating the effect of such interventions need reliable outcome measures. To date, the test-retest reliability of DT measures in patients with PD remains largely unknown. OBJECTIVE: The purpose of this study was to assess the reliability of DT outcome measures in patients with PD. DESIGN: A repeated-measures design was used. METHODS: Patients with PD ("on" medication, Mini-Mental State Examination score ≥24) performed 2 cognitive tasks (ie, backward digit span task and auditory Stroop task) and 1 functional task (ie, mobile phone task) in combination with walking. Tasks were assessed at 2 time points (same hour) with an interval of 6 weeks. Test-retest reliability was assessed for gait while performing each secondary task (DT gait) for both cognitive tasks while walking (DT cognitive) and for the functional task while walking (DT functional). RESULTS: Sixty-two patients with PD (age=39-89 years, Hoehn and Yahr stages II-III) were included in the study. Intraclass correlation coefficients (ICCs) showed excellent reliability for DT gait measures, ranging between .86 and .95 when combined with the digit span task, between .86 and .95 when combined with the auditory Stroop task, and between .72 and .90 when combined with the mobile phone task. The standard error of measurements for DT gait speed varied between 0.06 and 0.08 m/s, leading to minimal detectable changes between 0.16 and 0.22 m/s. With regard to DT cognitive measures, reaction times showed good-to-excellent reliability (digit span task: ICC=.75; auditory Stroop task: ICC=.82). LIMITATIONS: The results cannot be generalized to patients with advanced disease or to other DT measures. CONCLUSIONS: In people with PD, DT measures proved to be reliable for use in clinical studies and look promising for use in clinical practice to assess improvements after DT training. Large effects, however, are needed to obtain meaningful effect sizes.

Are factors related to dual-task performance in people with Parkinson's disease dependent on the type of dual task?

BACKGROUND: Impaired dual-task performance significantly impacts upon functional mobility in people with Parkinson's disease (PD). The aim of this study was to identify determinants of dual-task performance in people with PD in three different dual tasks to assess their possible task-dependency. METHODS: We recruited 121 home-dwelling patients with PD (mean age 65.93 years; mean disease duration 8.67 years) whom we subjected to regular walking (control condition) and to three dual-task conditions: walking combined with a backwards Digit Span task, an auditory Stroop task and a Mobile Phone task. We measured dual-task gait velocity using the GAITRite mat and dual-task reaction times and errors on the concurrent tasks as outcomes. Motor, cognitive and descriptive variables which correlated to dual-task performance (p < 0.20) were entered into a stepwise forward multiple linear regression model. RESULTS: Single-task gait velocity and executive function, tested by the alternating intake test, was significantly associated with gait velocity during the Digit Span (R(2) = 0.65; p < 0.001), the Stroop (R(2) = 0.73; p < 0.001) and the Mobile Phone task (R(2) = 0.62; p < 0.001). In addition, disease severity proved correlated to gait velocity during the Stroop task. Age was a surplus determinant of gait velocity while using a mobile phone. CONCLUSION: Single-task gait velocity and executive function as measured by a verbal fluency switching task were independent determinants of dual-task gait performance in people with PD. In contrast to expectation, these factors were the same across different tasks, supporting the robustness of the findings. Future study needs to determine whether these factors predict dual-task abnormalities prospectively.

Dual tasking in Parkinson's disease: should we train hazardous behavior?

Dual-task (DT) circumstances aggravate gait disorders in Parkinson's disease (PD) and are associated with an increased risk of falling and reduced functional mobility. Clinical rehabilitation guidelines for PD consider DT interventions as potentially hazardous and recommend avoiding them in daily life. The current article challenges this notion and addresses the necessity of implementing DT training in PD. First, underlying reasons for DT interference in PD and current theoretical models are discussed. Subsequently, different training approaches to tackle DT difficulties are put forward. Finally, the effectiveness and limitations of DT training in PD are reviewed. We conclude that there is a need for DT interventions in PD and recommend randomized, power-based studies to further test their efficacy.

Protocol for a randomized comparison of integrated versus consecutive dual task practice in Parkinson's disease: the DUALITY trial.

BACKGROUND: Multiple tasking is an integral part of daily mobility. Patients with Parkinson's disease have dual tasking difficulties due to their combined motor and cognitive deficits. Two contrasting physiotherapy interventions have been proposed to alleviate dual tasking difficulties: either to discourage simultaneous execution of dual tasks (consecutive training); or to practice their concurrent use (integrated training). It is currently unclear which of these training methods should be adopted to achieve safe and consolidated dual task performance in daily life. Therefore, the proposed randomized controlled trial will compare the effects of integrated versus consecutive training of dual tasking (tested by combining walking with cognitive exercises). METHODS AND DESIGN: Hundred and twenty patients with Parkinson's disease will be recruited to participate in this multi-centered, single blind, randomized controlled trial. Patients in Hoehn & Yahr stage II-III, with or without freezing of gait, and who report dual task difficulties will be included. All patients will undergo a six-week control period without intervention after which they will be randomized to integrated or consecutive task practice. Training will consist of standardized walking and cognitive exercises delivered at home four times a week during six weeks. Treatment is guided by a physiotherapist twice a week and consists of two sessions of self-practice using an MP3 player. Blinded testers will assess patients before and after the control period, after the intervention period and after a 12-week follow-up period. The primary outcome measure is dual task gait velocity, i.e. walking combined with a novel untrained cognitive task to evaluate the consolidation of learning. Secondary outcomes include several single and dual task gait and cognitive measures, functional outcomes and a quality of life scale. Falling will be recorded as a possible adverse event using a weekly phone call for the entire study period. DISCUSSION: This randomized study will evaluate the effectiveness and safety of integrated versus consecutive task training in patients with Parkinson's disease. The study will also highlight whether dual task gait training leads to robust motor learning effects, and whether these can be retained and carried-over to untrained dual tasks and functional mobility. TRIAL REGISTRATION: Clinicaltrials.gov NCT01375413.