677 research outputs found

    Wrist-Worn Physical Activity Trackers Tend To Underestimate Steps During Walking

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    International Journal of Exercise Science 10(5): 764-773, 2017. The purpose of this study was to determine step-count accuracy of pedometers at different walking speeds. Ten recreationally active participants walked at five treadmill speeds (0.89, 1.11, 1.34, 1.56, and 1.79 m/s) for five minutes while wearing four wrist-worn activity trackers (Fitbit Charge HR¼, Garmin Vivosmart HR¼, Apple iWatch¼, Jawbone UP3¼) and the hip-worn Digi-Walker¼. Each step was manually counted by a research technician (benchmark). Total step count at each speed was obtained for each device and compared to the benchmark using one-way MANOVA and Pearson correlation coefficient. For all five speeds, the Digi-Walker¼ yielded the most accurate values, averaging -0.4% difference from the benchmark counted steps, and showed the strongest correlation, r \u3e.730, p \u3c.05, at every speed. The Fitbit averaged the highest percent difference of -10.2% from the benchmark of counted steps, and underestimated steps at all speeds (p \u3c0.05). Garmin averaged a -2.7% step difference, Jawbone averaged a -5.3% step difference, and the iWatch showed a -7.9% step difference. Specifically, the Fitbit, Garmin, and Jawbone got progressively worse with increasing speed, whereas the iWatch performed the worst at the slowest and fastest speeds. All wrist-worn devices tested tended to underestimate steps. These data indicate that wrist-worn pedometers are inaccurate even with a specific designed purpose: count steps in a controlled manner. Because these devices are inaccurate in this setting, they remain highly questionable for accuracy in a real-world setting in which the definition of a “step” becomes less finite

    The Risk of Bias in Validity and Reliability Studies Testing Physiological Variables using Consumer-Grade Wearable Technology: A Systematic Review and WEAR-BOT Analysis

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    INTRODUCTION: Wearable technology is a quickly evolving field, and new devices with new features to measure/estimate physiological variables are being released constantly. Despite their use, the validity of the devices are largely unknown to the users or researchers, and the quality of the studies that do test validity and reliability vary widely. PURPOSE: Therefore, the purpose of this systematic review was to review the current validity and reliability literature concerning consumer-grade wearable technology measurements/estimates of physiological variables during exercise. Additionally, we sought to perform risk of bias assessments utilizing the novel WEArable technology Risk of Bias and Objectivity Tool (WEAR-BOT). METHODS: This review was conducted following PRISMA guidelines, searching 3 databases: Google Scholar, Scopus, and SPORTDiscus. After screening, 46 papers were identified that met the pre-determined criteria. Then data was extracted and risk of bias assessment performed by independent researchers. Descriptive statistics, weighted averages of mean absolute percentage error (MAPE) and Pearson correlations were calculated. Sample size statistics were performed utilizing the lower 95% confidence interval of the weighted correlation average. RESULTS: Of the 46 papers reviewed, 44 performed validity testing, while 9 performed reliability. The weighted average for MAPE was 12.48% for heart rate (HR) and 30.70% for energy expenditure (EE). The weighted average for Pearson correlations was 0.737 for HR and 0.672 for EE. Risk of bias assessment of validity studies resulted in 30/44 studies being classified as having a “High Risk of Bias”, and 14/44 having “Some Risk of Bias”. None had a “Low Risk of Bias”, according to the novel WEAR-BOT. For reliability studies, 7/9 were classified as “High Risk of Bias”, 2 as “Some Risk of Bias”, and 0 as “Low Risk of Bias”. CONCLUSION: The risk of bias assessment and descriptive statistics paint a troubling picture of the overall state of validity and reliability studies. Statistical analyses, methods, and reporting vary excessively. This review and associated WEAR-BOT analysis can be used by researchers to help standardize methodology, analytics, and reporting of validation and reliability studies of consumer-grade wearable technology

    Managing diabetes in people with dementia: protocol for a realist review

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    Background Worldwide, the prevalences of diabetes and dementia are both increasing, particularly in older people. Rates of diabetes in people with dementia are between 13 and 20 %. Diabetes management and diabetic self-care may be adversely affected by the presence of dementia. There is a need to know what interventions work best in the management of diabetes in people living with dementia (PLWD) in different settings and at different stages of the dementia trajectory. The overall aim is to develop an explanatory account or programme theory about ‘what works’ in the management of diabetes in people in what context and to identify promising interventions that merit further evaluation. Methods/design This study uses a realist approach including studies on the management of diabetes in older people, medication management, diabetes-related self-care, workforce issues and assessment and treatment. We will use an iterative, stakeholder driven, four-stage approach. Phase 1: development of initial programme theory/ies through a first scoping of the literature and consultation with key stakeholder groups (user/patient representatives, dementia-care providers, clinicians, diabetes and dementia researchers and diabetes specialists). Phase 2: systematic searches of the evidence to test and develop the theories identified in phase 1. Phase 3: validation of programme theory/ies with a purposive sample of participants from phase 1. Phase 4: actionable recommendations for the management of diabetes in PLWD. Discussion A realist synthesis of the evidence will provide a theoretical framework (i.e. an explanation of how interventions work, for whom, in what context and why) for practice and future research work that articulates the barriers and facilitators to effective management of diabetes in people with dementia. By providing possible explanations for the way in which interventions are thought to work and how change is achieved, it will demonstrate how to tailor an intervention to the setting and patient group. The propositions arising from the review will also inform the design of future intervention studies. Systematic review registration PROSPERO registration number CRD42015020625

    The Effects of Warm-up Duration on Cycling Time Trial Performance in Trained Cyclists

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    . The purpose of this study was to assess the effects of three different warm-up condi-tions on a 5K cycling time trial (TT). Sixteen trained cyclists completed the study. At the first testing session, participants completed a maximal graded exercise test to assess maximal oxygen consumption (VO2max) and a familiarization of the TT. At three subse-quent visits, the participants completed the TT after no warm up, short warm-up of three minutes at 60% VO2max, or long warm-up of ten minutes at 60% VO2max. The warm-up was assigned in randomized order. VO2, heart rate (HR), lactate, power, and speed were assessed after the warm-up, 1K, and completion of the 5K TT. There was no dif-ference between type of warm-up for time, power, cadence, speed, VO2, HR, or lactate levels at the end of the TT. There was no significant difference between type of warm-up for time, VO2 or HR at the end of the 1K split. Warm-up length was not impactful on 5K TT performance or during the first km of the TT in trained cyclists. These results con-flict with previous evidence indicating that a warm-up in endurance events primarily improved VO2 kinetics at the onset of the exercise

    Dementia case-finding in hospitals: a qualitative study exploring the views of healthcare professionals in English primary care and secondary care.

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    OBJECTIVES: In 2012-2013, the English National Health Service mandated hospitals to conduct systematic case-finding of people with dementia among older people with unplanned admissions. The method was not defined. The aim of this study was to understand current approaches to dementia case-finding in acute hospitals in England and explore the views of healthcare professionals on perceived benefits and challenges. DESIGN: Qualitative study involving interviews, focus groups and thematic content analysis. SETTING: Primary care and secondary care across six counties in the East of England. PARTICIPANTS: Hospital staff involved in dementia case-finding and primary care staff in the catchment areas of those hospitals. RESULTS: We recruited 23 hospital staff and 36 primary care staff, including 30 general practitioners (GPs). Analysis resulted in three themes: (1) lack of consistent approaches in case-finding processes, (2) barriers between primary care and secondary care which impact on case-finding outcomes and (3) perceptions of rationale, aims and impacts of case-finding. The study shows that there were variations in how well hospitals recorded and reported outcomes to GPs. Barriers between primary care and secondary care, including GPs' lack of access to hospital investigations and lack of clarity about roles and responsibilities, impacted case-finding outcomes. Staff in secondary care were more positive about the initiative than primary care staff, and there were conflicting priorities for primary care and secondary care regarding case-finding. CONCLUSIONS: The study suggests a more evidence-based approach was needed to justify approaches to dementia case-finding. Information communicated to primary care from hospitals needs to be comprehensive, appropriate and consistent before GPs can effectively plan further investigation, treatment or care. Follow-up in primary care further requires access to options for postdiagnostic support. There is a need to evaluate the outcomes for patients and the economic impact on health and care services across settings.NIH

    Physiological and emotional influence on heart rate recovery after submaximal exercise

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    The purpose of this study was to assess the role of cardiovascular fitness and emotional state in heart rate recovery after submaximal exercise. Fifty recreationally active subjects (male n=19, females n= 31) completed the study. Height, weight, body composition, and waist circumference were measured, with current emotional state assessed through completion of the Profile of Mood States questionnaire, followed by the Queen’s College Step Test to estimate maximal oxygen consumption (VO2max). Heart rate recovery was determined by the difference between assessments of peak heart rate during exercise and 1 minute post-exercise. Heart rate recovery was correlated with VO2 max, body composition, body mass index, waist circumference, resting heart rate, peak heart rate and the assessed mood states. A moderate negative correlation was found between heart rate recovery and resting heart rate (r = -.307, p = .032) and was the only variable to show significance. The results of this study disagree with previous literature as only one physiologic variable had a significant relationship with heart rate recovery. This may be because the participants recruited for this study were of at least average fitness and there were no significant signs of psychological stress in study participants at the time of testing

    Impact of modulation on CMB B-mode polarization experiments

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    We investigate the impact of both slow and fast polarization modulation strategies on the science return of upcoming ground-based experiments aimed at measuring the B-mode polarization of the CMB. Using simulations of the Clover experiment, we compare the ability of modulated and un-modulated observations to recover the signature of gravitational waves in the polarized CMB sky in the presence of a number of anticipated systematic effects. The general expectations that fast modulation is helpful in mitigating low-frequency detector noise, and that the additional redundancy in the projection of the instrument's polarization sensitivity directions onto the sky when modulating reduces the impact of instrumental polarization, are borne out by our simulations. Neither low-frequency polarized atmospheric fluctuations nor systematic errors in the polarization sensitivity directions are mitigated by modulation. Additionally, we find no significant reduction in the effect of pointing errors by modulation. For a Clover-like experiment, pointing jitter should be negligible but any systematic mis-calibration of the polarization coordinate reference system results in significant E-B mixing on all angular scales and will require careful control. We also stress the importance of combining data from multiple detectors in order to remove the effects of common-mode systematics (such as 1/f atmospheric noise) on the measured polarization signal. Finally we compare the performance of our simulated experiment with the predicted performance from a Fisher analysis. We find good agreement between the Fisher predictions and the simulations except for the very largest scales where the power spectrum estimator we have used introduces additional variance to the B-mode signal recovered from our simulations.Comment: Replaced with version accepted by MNRAS. Analysis of half-wave plate systematic (differential transmittance) adde

    Effectiveness of interventions to indirectly support food and drink intake in people with dementia : Eating and Drinking Well IN dementiA (EDWINA) systematic review

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    © 2016 Bunn et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BACKGROUND: Risks and prevalence of malnutrition and dehydration are high in older people but even higher in older people with dementia. In the EDWINA (Eating and Drinking Well IN dementiA) systematic review we aimed to assess effectiveness of interventions aiming to improve, maintain or facilitate food/drink intake indirectly, through food service or dining environment modification, education, exercise or behavioural interventions in people with cognitive impairment or dementia (across all settings, levels of care and support, types and degrees of dementia). METHODS: We comprehensively searched Medline and twelve further databases, plus bibliographies, for intervention studies with ≄3 cognitively impaired adult participants (any type/stage). The review was conducted with service user input in accordance with Cochrane Collaboration's guidelines. We duplicated assessment of inclusion, data extraction, and validity assessment, tabulating data. Meta-analysis (statistical pooling) was not appropriate so data were tabulated and synthesised narratively. RESULTS: We included 56 interventions (reported in 51 studies). Studies were small and there were no clearly effective, or clearly ineffective, interventions. Promising interventions included: eating meals with care-givers, family style meals, soothing mealtime music, constantly accessible snacks and longer mealtimes, education and support for formal and informal care-givers, spaced retrieval and Montessori activities, facilitated breakfast clubs, multisensory exercise and multicomponent interventions. CONCLUSIONS: We found no definitive evidence on effectiveness, or lack of effectiveness, of specific interventions but studies were small and short term. A variety of promising indirect interventions need to be tested in large, high-quality RCTs, and may be approaches that people with dementia and their formal or informal care-givers would wish to try. TRIAL REGISTRATION: The systematic review protocol was registered (CRD42014007611) and is published, with the full MEDLINE search strategy, on Prospero (http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42014007611).Peer reviewedFinal Published versio
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