86 research outputs found

    Physical activity and sedentary behaviour across the spectrum of chronic obstructive pulmonary disease

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    Chronic obstructive pulmonary disease (COPD) patients are generally more sedentary and less physically active than healthy adults; putting them at increased risk of hospitalisation and death. For patients with mild-moderate COPD, physical activity appears to be reduced compared with apparently healthy adults but differences in time spent sedentary are less well established. Additionally, there is a need for a greater understanding of the correlates of behaviour in mild-moderate patients with much of the existing literature focusing on more severe or mixed stage patient samples and with many studies lacking objective behavioural monitoring, not adjusting for confounders and a paucity of data on correlates of sedentary time. Despite having mild-moderate airflow obstruction, these patients also report a range of symptom burdens with some individuals reporting severe symptoms. Subsequently, these patients represent a sub-set of individuals who may require lifestyle interventions. Therefore, factors associated with patients reporting more severe symptoms need to be identified to help understand how this phenomenon may manifest and be intervened upon. For patients with more advanced COPD who are admitted to hospital for an acute exacerbation behavioural intervention focussing on less intense movement may be a more suitable approach for reducing the risk of readmissions than more intense physical activity or exercise. To date no studies have specifically targeted reductions in sedentary behaviour in COPD. In addition, wearable self-monitoring technology may facilitate the provision of such interventions, removing important participation barriers such as travel and cost, but this has not been sufficiently examined in COPD. This thesis investigated: (i) objectively measured physical activity and sedentary time and the correlates of these behaviours for mild-moderate COPD patients and apparently healthy adults (Study One); (ii) factors associated with self-reported symptom severity and exacerbation history in mild-moderate COPD patients (Study Two) and (iii) the feasibility and acceptability of a home-based sedentary behaviour intervention using wearable self-monitoring technology for COPD patients following an acute exacerbation (Study Three). Methods: Study One: COPD patients were recruited from general practitioners and apparently healthy adults from community advertisements. Objectively measured moderate-to-vigorous physical activity (MVPA), light activity and sedentary time for 109 mild-moderate COPD patients and 135 apparently healthy adults were obtained by wrist-worn accelerometry. Patients with at least four valid days (≥10 waking hours) out of a possible seven were included in analysis. A range of demographic, social, symptom-based, general health and physical factors were examined in relation to physical activity and sedentary time using correlations and linear regressions controlling for confounders (age, gender, smoking status, employment status and accelerometer waking wear time). Study Two: In 107 patients recruited from general practitioners, symptoms were assessed using the COPD Assessment Test (CAT) and Modified Medical Research Council (mMRC) questionnaires. Twelve-month exacerbation history was self-reported. Exercise capacity was assessed via incremental shuttle walk test (ISWT) and self-reported usual walking speed. Physical activity and sedentary time were obtained from a wrist-worn accelerometer. Study Three: Patients were randomised in-hospital into a usual care (Control), Education or Education + Feedback group with the intervention lasting 14 days following discharge. The intervention groups received information about reducing prolonged sitting. The Education + Feedback group also received real-time feedback on their sitting time, number of stand-ups and step count at home through an inclinometer linked to a smart device app. The inclinometer also provided vibration prompts to encourage movement when the wearer had been sedentary for too long. Feasibility of recruitment (e.g. uptake and retention) and intervention delivery (e.g. fidelity) were assessed. Acceptability of the intervention technology (e.g. wear compliance, app usage and response to vibration prompts) was also examined. Results: Study One: COPD patients were more sedentary (592±90 versus 514±93 minutes per day, p20 or an mMRC score of ≥2 had lower VMCPM, were more sedentary and took part in less light activity than patients reporting a CAT score of 0-10 or mMRC of 0, respectively. Patients reporting ≥2 exacerbations took part in less MVPA than patients reporting zero exacerbations. Study Three: Study uptake was 31.5% providing a final sample of 33 COPD patients. Retention of patients at two-week follow-up was 51.5% (n=17). Reasons for drop-out were mostly related to being unable to cope with their COPD. Patients wore the inclinometer for 11.8±2.3 days (and charged it 8.4±3.9 times) with at least one vibration prompt occurring on 9.0±3.4 days over the 14 day study period. Overall, 325 vibration prompts occurred with patients responding 106 times (32.6%). 40.6% of responses occurred within 5 minutes of the prompt with patients spending 1.4±0.8 minutes standing and 0.4±0.3 minutes walking, taking 21.2±11.0 steps. Discussion: Study One: COPD patients were less active and more sedentary than apparently healthy adults; however, factors predicting behaviour were similar between groups. Correlates differed between sedentary time, light activity and MVPA for both groups. Interventions to boost physical activity levels and reduce sedentary time should be offered to patients with mild-moderate COPD, particularly those reporting more severe breathlessness. Study Two: Worse exercise capacity, low levels of physical activity and more time spent sedentary are some of the factors associated with patients of the same severity of airflow limitation reporting differing symptom severities. These patients may benefit from both lifestyle and exercise interventions. Study Three: Recruitment and retention rates suggest a trial targeting sedentary behaviour in hospitalised COPD patients is feasible. A revised intervention, building on the successful components of the present feasibility study is justified. Conclusion: The findings from this thesis have contributed a greater understanding of physical activity and sedentary behaviour in COPD and can inform the development of tailored physical activity and sedentary behaviour interventions for patients across the grades of COPD severity

    Chronic obstructive pulmonary disease (COPD), illness narratives and Elias's sociology of knowledge

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    This paper draws on Elias’s sociology of knowledge to provide a critical assessment of illness narratives. Focusing on a cohort of chronic obstructive pulmonary disease (COPD) patients (n=26), the paper employs a comparative analysis of mixed method data derived from qualitative interviews, quantitative questionnaires, and physiological and accelerometer testing. The article firstly compares four narratives conveyed in interviews with the broader paradigmatic approach to illness narratives and existing COPD-specific studies. It then explores the relationship between these ‘stories’ and COPD patients’ biographical contingencies (e.g. age, wealth, context of diagnosis) and embodied condition (e.g. co-morbidities, lung function), demonstrating how illness narratives are shaped by both broader social structural factors and embodied experience. Invoking Elias we further find that different narrative subthemes are varyingly affected by patients’ emotional engagement and ontological security and thus that people are differently enabled or constrained to present illness narratives that are consistent with their broader social and physical condition. Consequently, while narratives, social structure and embodied experience are interdependent, our reading of ‘truth’ must be sensitive to the social positioning of the ‘teller’ and the specific content being relayed. The paper therefore presents a more systematic, comparative, bio-psycho-social analysis than has hitherto been produced

    Resistance to data loss from the Freestyle Libre:Impact on glucose variability indices and recommendations for data analysis

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    Like many wearables, flash glucose monitoring relies on user compliance and is subject to missing data. As recent research is beginning to utilise glucose technologies as behaviour change tools, it is important to understand whether missing data is tolerable. Complete Freestyle Libre data files were amputed to remove 1-6 hours of data both at random and over mealtimes (breakfast, lunch and dinner). Absolute percent errors (MAPE) and intraclass correlation coefficients (ICC) were calculated to evaluate agreement and reliability. Thirty-two (91%) participants provided at least one complete day (24-hours) of data (age: 44.8±8.6 years, female: 18 (56%); mean fasting glucose: 5.0±0.6 mmol/L). Mean and CONGA (60 minutes) were robust to data loss (MAPE ≤3%). Larger errors were calculated for standard deviation, coefficient of variation (CV) and MAGE at increasing missingness (MAPE 2-10%, 2-9% and 4-18%, respectively). ICC decreased as missing data increased, with most indicating excellent reliability (>0.9) apart from certain MAGE ICC, which indicated good reliability (0.84-0.9). Researchers and clinicians should be aware of the potential for larger errors when reporting standard deviation, CV and MAGE at higher rates of data loss in nondiabetic populations. But where mean and CONGA are of interest, data loss is less of a concern. Novelty: As research now utilises flash glucose monitoring as behavioural change tools in nondiabetic populations, it is important to consider the influence of missing data. Glycaemic variability indices of mean and CONGA are robust to data loss, but standard deviation, CV and MAGE are influenced at higher rates of missingness

    Sensing interstitial glucose to nudge active lifestyles (SIGNAL): Feasibility of combining novel self-monitoring technologies for persuasive behaviour change

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    © Article author(s) 2017. Introduction Increasing physical activity (PA) reduces the risk of developing diabetes, highlighting the role of preventive medicine approaches. Changing lifestyle behaviours is difficult and is often predicated on the assumption that individuals are willing to change their lifestyles today to reduce the risk of developing disease years or even decades later. The self-monitoring technologies tested in this study will present PA feedback in real time, parallel with acute physiological data. Presenting the immediate health benefits of being more physically active may help enact change by observing the immediate consequences of that behaviour. The present study aims to assess user engagement with the self-monitoring technologies in individuals at moderate-to-high risk of developing type 2 diabetes. Methods and analysis 45 individuals with a moderate-to-high risk, aged ≥40 years old and using a compatible smartphone, will be invited to take part in a 7-week protocol. Following 1 week of baseline measurements, participants will be randomised into one of three groups: group 1 -glucose feedback followed by biobehavioural feedback (glucose plus PA); group 2 - PA feedback followed by biobehavioural feedback; group 3 - biobehavioural feedback. A PA monitor and a flash glucose monitor will be deployed during the intervention. Participants will wear both devices throughout the intervention but blinded to feedback depending on group allocation. The primary outcome is the level of participant engagement and will be assessed by device use and smartphone usage. Feasibility will be assessed by the practicality of the technology and screening for diabetes risk. Semistructured interviews will be conducted to explore participant experiences using the technologies. Trial registration number ISRCTN17545949. Registered on 15/05/2017

    Examining the use of glucose and physical activity self-monitoring technologies in individuals at moderate to high risk of developing type 2 diabetes: randomized trial

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    Background Self-monitoring of behavior (namely, diet and physical activity) and physiology (namely, glucose) has been shown to be effective in type 2 diabetes (T2D) and prediabetes prevention. By combining self-monitoring technologies, the acute physiological consequences of behaviors could be shown, prompting greater consideration to physical activity levels today, which impact the risk of developing diabetes years or decades later. However, until recently, commercially available technologies have not been able to show individuals the health benefits of being physically active. Objective The objective of this study was to examine the usage, feasibility, and acceptability of behavioral and physiological self-monitoring technologies in individuals at risk of developing T2D. Methods A total of 45 adults aged ≥40 years and at moderate to high risk of T2D were recruited to take part in a 3-arm feasibility trial. Each participant was provided with a behavioral (Fitbit Charge 2) and physiological (FreeStyle Libre flash glucose monitor) monitor for 6 weeks, masked according to group allocation. Participants were allocated to glucose feedback (4 weeks) followed by glucose and physical activity (biobehavioral) feedback (2 weeks; group 1), physical activity feedback (4 weeks) followed by biobehavioral feedback (2 weeks; group 2), or biobehavioral feedback (6 weeks; group 3). Participant usage (including time spent on the apps and number of glucose scans) was the primary outcome. Secondary outcomes were the feasibility (including recruitment and number of sensor displacements) and acceptability (including monitor wear time) of the intervention. Semistructured qualitative interviews were conducted at the 6-week follow-up appointment. Results For usage, time spent on the Fitbit and FreeStyle Libre apps declined over the 6 weeks for all groups. Of the FreeStyle Libre sensor scans conducted by participants, 17% (1798/10,582) recorded rising or falling trends in glucose, and 24% (13/45) of participants changed ≥1 of the physical activity goals. For feasibility, 49% (22/45) of participants completed the study using the minimum number of FreeStyle Libre sensors, and a total of 41 sensors were declared faulty or displaced. For acceptability, participants wore the Fitbit for 40.1 (SD 3.2) days, and 20% (9/45) of participants and 53% (24/45) of participants were prompted by email to charge or sync the Fitbit, respectively. Interviews unearthed participant perceptions on the study design by suggesting refinements to the eligibility criteria and highlighting important issues about the usability, wearability, and features of the technologies. Conclusions Individuals at risk of developing T2D engaged with wearable digital health technologies providing behavioral and physiological feedback. Modifications are required to both the study and to commercially available technologies to maximize the chances of sustained usage and behavior change. The study and intervention were feasible to conduct and acceptable to most participants. Trial Registration International Standard Randomized Controlled Trial Number (ISRCTN) 17545949; isrctn.com/ISRCTN1754594

    Physical activity and respiratory health (PhARaoH): Data from a cross-sectional study

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    The dataset consists of a densely phenotyped sample of adults collected from March to August 2014. The dataset captures behavioural, physical, physiological and psychosocial characteristics of individuals with and without a General Practitioner diagnosis of chronic obstructive pulmonary disease (COPD). Data were collected at Glenfield Hospital on 436 individuals (139 COPD patients and 297 apparently healthy adults) aged 40–75 years, residing in Leicestershire and Rutland, United Kingdom. The dataset includes seven days of raw wrist-worn accelerometry, venous blood biomarkers, non-invasive point-of-care cardio-metabolic risk profiles, physical measures and questionnaire data

    High Stability Engine Control (HISTEC) Flight Test Results

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    The High Stability Engine Control (HISTEC) Program, managed and funded by the NASA Lewis Research Center, is a cooperative effort between NASA and Pratt & Whitney (P&W). The program objective is to develop and flight demonstrate an advanced high stability integrated engine control system that uses real-time, measurement-based estimation of inlet pressure distortion to enhance engine stability. Flight testing was performed using the NASA Advanced Controls Technologies for Integrated Vehicles (ACTIVE) F-15 aircraft at the NASA Dryden Flight Research Center. The flight test configuration, details of the research objectives, and the flight test matrix to achieve those objectives are presented. Flight test results are discussed that show the design approach can accurately estimate distortion and perform real-time control actions for engine accommodation
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