Daily step count predicts acute exacerbations in a US cohort with COPD

Prevalence and prognostic importance of exercise limitation and physical inactivity in COPD

Exercise limitation and physical inactivity are separate, but related constructs. Both are commonly present in individuals with COPD, contribute to disease burden over and above the respiratory impairments, and are independently predictive of adverse outcomes. Because of this, clinicians should consider assessing these variables in their patients with COPD. Field tests of exercise performance such as the 6-min walk test and the incremental and endurance shuttle walk tests require limited additional resources, and results correlate with negative outcomes. Laboratory measures of exercise performance using a treadmill or cycle ergometer assess exercise capacity, provide prognostic information and have the advantage of explaining physiological mechanisms (and their interactions) underpinning exercise limitation. Limitations in exercise capacity (i.e. "cannot do") and physical inactivity (i.e. "do not do") are both associated with mortality; exercise limitation appears to be the more important driver of this outcome.

Maintenance Pulmonary Rehabilitation: An Update and Future Directions

The Global Initiative for Chronic Obstructive Lung Disease guidelines recommend pulmonary rehabilitation (PR) for individuals with COPD to improve exercise capacity and health-related quality of life (HRQOL) and reduce symptoms of dyspnea. For cost-effectiveness in COPD care, PR is second only to smoking cessation. However, PR programs typically last 9-12 weeks. The benefits of PR in terms of exercise capacity and HRQOL often decrease toward pre-PR levels as early as 3-6 months after completing PR if patients do not continue to engage in exercise. This review will (1) briefly summarize the efficacy data that informed the 2023 American Thoracic Society (ATS) clinical practice guidelines for maintenance PR, (2) discuss exercise components of maintenance PR studied since 2020 when the last papers were included in the ATS guidelines, (3) explore future directions for delivery of maintenance PR using technology-mediated models, and (4) examine the need for behavior change techniques informed by theoretical models that underpin long-term behavior change. This review will focus on persons with COPD who have completed an out-patient core initial PR program as most of the data on maintenance PR have been published in this patient population. Core PR typically implies a facility-based initial intensive structured program. All patients who complete a core initial PR program should be counseled by PR staff at the discharge visit to engage in ongoing exercise. This usual care is equally as important as referral to a formal PR maintenance program. It is critical to emphasize that usual care after core initial PR means all patients should be supported to participate in regular ongoing exercise, regardless of whether supervised maintenance PR is available. Currently, the optimal frequency, exercise and/or physical activity content, and delivery mode for maintenance PR in persons with COPD and other chronic respiratory diseases remain unknown. Patient safety and degree of in-person supervision required due to the severity of the underlying lung disease need to be considered. Future research of maintenance PR should be underpinned by behavior change techniques. Finally, in the setting of finite resources, balancing the competing priorities of core initial programs with those of maintenance PR programs needs to be achieved.

The experiences of people with chronic obstructive pulmonary disease (COPD) using activity monitors in everyday life: an interpretative phenomenological study

PURPOSE

Understanding the experiences of people with Chronic Obstructive Pulmonary Disease (COPD) using activity monitors in daily life could support the utilisation of technology within healthcare to increase physical activity and support self-management. This qualitative study aimed to explore the experiences of people with COPD using activity monitors at home in everyday life.

METHODS

Semi-structured face-to-face or telephone interviews were conducted with seven people with COPD between August 2018 and June 2020. Participants had all used an activity monitor within the last year (Fitbit, Garmin, or Apple Watch). Interviews were analysed in-depth using Interpretative Phenomenological Analysis (IPA).

RESULTS

Four themes, developed using IPA, highlight participants' engagement with activity monitors and integrating them into their lives: (1) Motivational features to monitor activity, (2) Importance of setting achievable goals, (3) Developing knowledge and awareness, and (4) Integration into everyday life for self-management.

CONCLUSION

Activity monitors were perceived to be beneficial and useful to people with COPD, not just for monitoring their activity, but also helping to self-manage their condition. Activity monitors may be a useful tool within rehabilitation and healthcare services for COPD.

Rural disparities impact response to a web-based physical activity self-management intervention in COPD: A secondary analysis

PURPOSE

This secondary exploratory analysis examined rural-urban differences in response to a web-based physical activity self-management intervention for chronic obstructive pulmonary disease (COPD).

METHODS

Participants with COPD (N = 239 US Veterans) were randomized to either a multicomponent web-based intervention (goal setting, iterative feedback of daily step counts, motivational and educational information, and an online community forum) or waitlist-control for 4 months with a 12-month follow-up. General linear modeling estimated the impact of rural/urban status (using Rural-Urban Commuting Area [RUCA] codes) on (1) 4- and 12-month daily step-count change compared to waitlist-control, and (2) intervention engagement (weekly logons and participant feedback).

FINDINGS

Rural (n = 108) and urban (n = 131) participants' mean age was 66.7±8.8 years. Rural/urban status significantly moderated 4-month change in daily step counts between randomization groups (p = 0.041). Specifically, among urban participants, intervention participants improved by 1500 daily steps more than waitlist-control participants (p = 0.001). There was no difference among rural participants. In the intervention group, rural participants engaged less with the step-count graphs on the website than urban participants at 4 months (p = 0.019); this difference dissipated at 12 months. More frequent logons were associated with greater change in daily step counts (p = 0.004); this association was not moderated by rural/urban status.

CONCLUSIONS

The web-based intervention was effective for urban, but not rural, participants at 4 months. Rural participants were also less engaged at 4 months, which may explain differences in effectiveness. Technology-based interventions can help address urban-rural disparities in patients with COPD, but may also contribute to them unless resources are available to support engagement with the technology.

Using an electronic diary and wristband accelerometer to detect exacerbations and activity levels in COPD: a feasibility study

Background

Early and accurate identification of acute exacerbations of COPD may lead to earlier treatment and prevent hospital admission. Electronic diaries have been developed for symptom monitoring and accelerometers to monitor activity. However, it is unclear whether this technology is usable in the COPD population. This study aimed to assess the feasibility of an electronic diary (eDiary) for symptom reporting using the MoreCare app and activity monitoring with the Garmin Vivofit 2 in COPD.

Methods

Participants were recruited from the London COPD Cohort. Participants were provided a Garmin Vivofit 2 activity monitor and an android tablet with the MoreCare app for a period of 3 months.

Results

25 COPD patients were recruited (mean±sd age 70.8±7.1 years, forced expiratory volume in 1 s (FEV1) 49.8±14.8% predicted). Age, gender, disease severity and exacerbation frequency had no impact on eDiary compliance. There was a moderate positive correlation between median daily very active minutes and FEV1 % pred (ρ=0.62, p=0.005). Daily step counts decreased during the initial 7 days of exacerbation and recovery compared to a pre-exacerbation baseline. A decision-tree model identified change in sputum colour, change in step count, severity of cold, exacerbation history and use of rescue medication as the most important predictors of acute exacerbations of COPD in this cohort.

Conclusions

Symptom and activity monitoring using digital technology is feasible in COPD. Further large-scale digital health studies are needed to assess whether eDiaries can be used to identify patients at risk of exacerbation and guide early intervention.

Stakeholder Perceptions of a Web-Based Physical Activity Intervention for COPD: A Mixed-Methods Study

Technology-based physical activity interventions have been shown to be efficacious in chronic obstructive pulmonary disease (COPD), though their potential impact has not been fully realized due to ineffective implementation. We used a convergent, parallel mixed-methods design to identify patient- and provider-facing barriers and facilitators to implementing a rigorously studied web-based physical activity intervention for COPD. Quantitative surveys (based on the unified theory of acceptance and use of technology; range 1 (poor usability)-5 (high usability)) and semi-structured interviews (guided by the practical robust implementation and sustainability model) assessed the perspectives of 15 patients and 15 health care providers. The patients and providers rated the usability of the intervention as high (median = 5.0, IQR = 1.0). For both patients and providers, the main facilitators included: the potential high impact of the intervention on patient health, the usefulness of the intervention for unmet clinical needs, and the perceived ease of use of the intervention. The main barriers identified were digital literacy and its fit with current clinical workflows. Implementation efforts may benefit from supporting patients' use of the website and developing strategies to integrate referrals to the intervention and the monitoring of patients into current clinical infrastructures.

Depression Symptoms and Physical Activity in Veterans With COPD: Insights From a Web-Based, Pedometer-Mediated Physical Activity Intervention

BACKGROUND

Depression is known to limit physical activity (PA) among individuals with chronic obstructive pulmonary disease (COPD). However, whether and how depression influences the effectiveness of PA interventions is unknown.

PURPOSE

The study examined the association between baseline depression symptoms and change in daily step count and whether group assignment to a web-based, pedometer-mediated PA intervention moderated the association between baseline depression symptoms and change in daily step count.

METHODS

Secondary analysis included two cohorts of U.S. Veterans with COPD (n = 212; 97% male; mean age 69 ± 8 years) assessed at baseline and 3 months. Cohorts 1 and 2 were randomly assigned to the same PA intervention (n = 111) or a control group (n = 101). Multivariate regressions tested the main effects of baseline depression symptoms (BDI-II total and cognitive-affective and somatic subscales) on change in daily steps, as well as the interaction between baseline BDI-II and subscales and group assignment on change in daily steps.

RESULTS

Greater BDI-II total score (B = -31.8, SE = 14.48, p = .030) and somatic subscale scores (B = -99.82, SE = 35.76, p = .006) were associated with less improvement in daily step count. There was a significant interaction between baseline cognitive-affective subscale and the intervention predicting change in daily step count (B = -88.56, SE = 42.31, p = .038). When cognitive-affective subscale scores were ≥1 SD above the mean, the intervention was no longer associated with an increase in daily step count (p = .585).

CONCLUSIONS

Depression should be routinely assessed and targeted as part of PA promotion efforts.

The Impact of a Wearable Activity Tracker and Structured Feedback Program on Physical Activity in Hemodialysis Patients: The Step4Life Pilot Randomized Controlled Trial

RATIONALE & OBJECTIVE

People with end-stage kidney disease (ESKD) have very low physical activity, and the degree of inactivity is strongly associated with morbidity and mortality. We assessed the feasibility and effectiveness of a 12-week intervention coupling a wearable activity tracker (FitBit) and structured feedback coaching versus wearable activity tracker alone on changes in physical activity in hemodialysis patients.

STUDY DESIGN

Randomized controlled trial.

SETTING & PARTICIPANTS

55 participants with ESKD receiving hemodialysis who were able to walk with or without assistive devices recruited from a single academic hemodialysis unit between January 2019 and April 2020.

INTERVENTIONS

All participants wore a Fitbit Charge 2 tracker for a minimum of 12 weeks. Participants were randomly assigned 1:1 to a wearable activity tracker plus a structured feedback intervention versus the wearable activity tracker alone. The structured feedback group was counseled weekly on steps achieved after randomization.

OUTCOME

The outcome was step count, and the main parameter of interest was the absolute change in daily step count, averaged per week, from baseline to completion of 12 weeks intervention. In the intention-to-treat analysis, mixed-effect linear regression analysis was used to evaluate change in daily step count from baseline to 12-weeks in both arms.

RESULTS

Out of 55 participants, 46 participants completed the 12-week intervention (23 per arm). The mean age was 62 (± 14 SD) years; 44% were Black, and 36% were Hispanic. At baseline, step count (structured feedback intervention: 3,704 [1,594] vs wearable activity tracker alone: 3,808 [1,890]) and other participant characteristics were balanced between the arms. We observed a larger change in daily step count in the structured feedback arm at 12 weeks relative to use of the wearable activity tracker alone arm (Δ 920 [±580 SD] versus Δ 281 [±186 SD] steps; between-group difference Δ 639 [±538 SD] steps; P<0.05).

LIMITATIONS

Single-center study and small sample size.

CONCLUSION

This pilot randomized controlled trial demonstrated that structured feedback coupled with a wearable activity tracker led to a greater daily step count that was sustained over 12 weeks relative to a wearable activity tracker alone. Future studies are required to determine longer-term sustainability of the intervention and potential health benefits in hemodialysis patients.

FUNDING

Grants from industry (Satellite Healthcare) and government (National Institute for Diabetes and Digestive and Kidney Diseases (NIDDK).

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT05241171.

Using remotely monitored patient activity patterns after hospital discharge to predict 30 day hospital readmission: a randomized trial

Hospital readmission prediction models often perform poorly, but most only use information collected until the time of hospital discharge. In this clinical trial, we randomly assigned 500 patients discharged from hospital to home to use either a smartphone or wearable device to collect and transmit remote patient monitoring (RPM) data on activity patterns after hospital discharge. Analyses were conducted at the patient-day level using discrete-time survival analysis. Each arm was split into training and testing folds. The training set used fivefold cross-validation and then final model results are from predictions on the test set. A standard model comprised data collected up to the time of discharge including demographics, comorbidities, hospital length of stay, and vitals prior to discharge. An enhanced model consisted of the standard model plus RPM data. Traditional parametric regression models (logit and lasso) were compared to nonparametric machine learning approaches (random forest, gradient boosting, and ensemble). The main outcome was hospital readmission or death within 30 days of discharge. Prediction of 30-day hospital readmission significantly improved when including remotely-monitored patient data on activity patterns after hospital discharge and using nonparametric machine learning approaches. Wearables slightly outperformed smartphones but both had good prediction of 30-day hospital-readmission.

Objective Measurement of Physical Activity and Sedentary Behavior in Patients with Chronic Obstructive Pulmonary Disease: Points to Keep in Mind during Evaluations

Objective measurement methods using accelerometers have become the mainstream approach for evaluating physical activity (PA) and sedentary behavior (SB). However, several problems face the objective evaluation of PA and SB in patients with chronic obstructive pulmonary disease (COPD). For example, indicators of PA differ depending on whether the accelerometer detects the kind of activity on the one hand, or its intensity on the other. Measured data are also strongly influenced by environmental factors (weather, season, employment status, etc.) and methodological factors (days with uncommon activities, non-wearing time, minimum required wearing time per day, minimum number of valid days required, etc.). Therefore, adjusting for these factors is required when evaluating PA or SB, especially when evaluating the effects of intervention. The exclusion of sleeping time, unification of total measurement time, and minimization of the required wearing time per day might be more important for the evaluation of ST than for evaluating PA. The lying-down-time-to-sitting-time ratio was shown to be larger in COPD patients than in healthy subjects. In this review, we clarified the problems encountered during objective evaluations of PA and SB in patients with COPD and encouraged investigators to recognize the presence of these problems and the importance of adjusting for them.

Physical Activity, Air Pollution Exposure, and Lung Function Interactions Among Adults with COPD

Rationale

Although physical activity is strongly encouraged for patients with chronic obstructive pulmonary disease (COPD), it is unknown if physical activity affects daily exposure to air pollution, or whether it attenuates or exacerbates the effects of pollution on the airways among adults with COPD.

Methods

Thirty former smokers with moderate-to-severe COPD in Boston were followed for 4 non-consecutive months in different seasons. We assessed daily lung function (forced expiratory volume in 1 second [FEV1] and forced vital capacity [FVC]), prior-day personal pollutant exposure measured by portable air quality monitors (fine particulate matter [PM2.5] nitrogen oxide [NO2], and ozone [O3]), and daily step count. We constructed multi-level linear mixed-effects models with random intercepts for person and person-observation month, adjusting for demographic/seasonal covariates to test if step count was associated with daily pollution exposure, and if associations between prior-day pollution and lung function differed based on prior-day step count. Where effect modification was found, we performed stratified analyses by tertile of step count.

Results

Higher daily step count was associated with higher same-day personal exposure to PM2.5, and O3 but not NO2. Each interquartile range (IQR) increment in step count was associated with 0.97 µg/m3 (95%CI: 0.30, 1.64) higher exposure to PM2.5 and 0.15 parts per billion (95% CI: -0.05, 0.35) higher exposure to O3 in adjusted models. We observed an interaction between prior-day NO2 and step count on FEV1 and FVC (Pinteraction<0.05) in which the negative associations between NO2 and lung function were reduced or absent at higher levels of daily activity. For example, FEV1 was 28.5mL (95%CI: -41.0, -15.9) lower per IQR of NO2 in the lowest tertile of step count, but there was no association in the highest tertile of step count (-1.6mL, 95% CI: -18.4, 15.2).

Conclusions

Higher physical activity was associated with modestly higher daily exposure to PM2.5 and O3 and may attenuate the association between NO2 exposure and lung function.

"Bring Your Own Device"-A New Approach to Wearable Outcome Assessment in Trauma

Background and Objectives: Outcome data from wearable devices are increasingly used in both research and clinics. Traditionally, a dedicated device is chosen for a given study or clinical application to collect outcome data as soon as the patient is included in a study or undergoes a procedure. The current study introduces a new measurement strategy, whereby patients' own devices are utilized, allowing for both a pre-injury baseline measure and ability to show achievable results. Materials and Methods: Patients with a pre-existing musculoskeletal injury of the upper and lower extremity were included in this exploratory, proof-of-concept study. They were followed up for a minimum of 6 weeks after injury, and their wearable outcome data (from a smartphone and/or a body-worn sensor) were continuously acquired during this period. A descriptive analysis of the screening characteristics and the observed and achievable outcome patterns was performed. Results: A total of 432 patients was continuously screened for the study, and their screening was analyzed. The highest success rate for successful inclusion was in younger patients. Forty-eight patients were included in the analysis. The most prevalent outcome was step count. Three distinctive activity data patterns were observed: patients recovering, patients with slow or no recovery, and patients needing additional measures to determine treatment outcomes. Conclusions: Measuring outcomes in trauma patients with the Bring Your Own Device (BYOD) strategy is feasible. With this approach, patients were able to provide continuous activity data without any dedicated equipment given to them. The measurement technique is especially suited to particular patient groups. Our study's screening log and inclusion characteristics can help inform future studies wishing to employ the BYOD design.

A Web-Based Mind-Body Intervention (Mindful Steps) for Promoting Walking in Chronic Cardiopulmonary Disease: Insights From a Qualitative Study

Background

Given the deleterious effects of physical inactivity in persons with chronic obstructive pulmonary disease (COPD) and/or heart failure (HF), interventions that promote long-term daily physical activity are needed. Mindful Steps, designed to promote walking behaviors in COPD and HF, is a multicomponent intervention that integrates mind-body content with other self-regulatory components. The aim of the current qualitative study was to characterize participants' experiences with Mindful Steps and understand the perceived influence of the intervention on walking and health.

Method

In the context of a pilot randomized controlled feasibility trial comparing the year-long Mindful Steps program to usual care among individuals with COPD and HF, semi-structured qualitative interviews were administered at 6- and 12-months. Interviews were audio recorded and transcribed. The constant comparative method was used to code transcripts, identify categories, and develop interrelated themes.

Results

Nineteen participants (63% female; Mage = 70.2 years, SD = 6.95) who were randomized to the intervention group completed the 6-month interview and 17 completed the 12-month interview. The pedometer with feedback, live group classes, and mind-body videos were described as the most helpful intervention components. Participants learned several strategies that helped their walking (e.g., breathing regulation and awareness, body awareness, mind-body techniques, pacing), described walking as enjoyable, and identified internal reasons for walking (e.g., to feel good). They also reported several physical and mental health benefits of the intervention. Some participants reported limited influence of the intervention on walking or health. Many participants continued to use the strategies they learned in the first half of the intervention at 12-months.

Conclusions

The mind-body content of Mindful Steps appeared to positively influence walking behaviors. Participants' experiences with the intervention helped to identify areas for future intervention refinement. Future quantitative work is needed to corroborate these qualitative findings and assess the efficacy of the intervention on long-term physical activity engagement.

Trial Registration

This trial is registered in Clinical Trials.gov, ID number NCT01551953.

Discriminant Validity of a Single Clinical Question for the Screening of Inactivity in Individuals Living with COPD

Introduction

Quantifying physical activity in chronic obstructive pulmonary disease (COPD) with questionnaires and activity monitors in clinical practice is challenging. The aim of the present study was to analyse the discriminant validity of a single clinical question for the screening of inactive individuals living with COPD.

Methods

A multicentre study was carried out in stable COPD individuals both in primary and tertiary care. Patients wore the Dynaport accelerometer for 8 days and then answered 5 physical activity questions developed for the study, referring to the week in which their physical activity was monitored. Receiver operating characteristic (ROC) curve analysis with physical activity level (PAL) as the gold standard reference was used to determine the best cut-off point for each of the 5 clinical physical activity questions tested.

Results

A total of 86 COPD participants were analysed (males 68.6%; mean (SD) age 66.6 (8.5) years; FEV₁ 50.9 (17.3)% predicted; mean of 7305 (3906) steps/day). Forty-two (48.8%) participants were considered physically inactive (PAL ≤1.69). Answers to 4 out of 5 questions significantly differed in active vs inactive patients. The Kappa index and ROC curves showed that the answer to the question "On average, how many minutes per day do you walk briskly?" had the best discriminative capacity for inactivity, with an area under the curve (AUC) (95% Confidence interval (CI)) of 0.73 (0.63-0.84) and 30 min/day was identified as the best cut-off value (sensitivity (95% CI): 0.75 (0.60-0.87); specificity: 0.76 (0.61-0.88)).

Conclusion

The present results indicate that self-reported brisk walk time lower than 30 min/day may be a valid tool for the screening of inactivity in individuals living with COPD in routine care, if more detailed physical activity measures are not feasible.

Cost savings associated with a web-based physical activity intervention for COPD

OBJECTIVE

To estimate the cost savings associated with a pedometer-based, web-mediated physical activity intervention in a cohort of US veterans with chronic obstructive pulmonary disease (COPD).

STUDY DESIGN

Economic analysis.

METHODS

We constructed a decision tree from the health care system perspective incorporating adjusted relative risk of a pedometer-based, web-mediated intervention for COPD-related acute exacerbations, acute exacerbation-related costs (ie, emergency department visits and hospitalizations), and intervention-related costs. Total COPD-related costs were estimated per patient across 12 months. Probabilistic sensitivity analysis with Monte Carlo simulation was used to estimate uncertainty in the model findings.

RESULTS

In the deterministic (base case) model, the model estimated costs to be $4236 per participant who used the pedometer-based, web-mediated intervention compared with $7913 per participant in the control group (estimated $3677 saved in 1 year compared with the control group). The model findings were robust to probabilistic sensitivity analysis, with a difference in mean costs of $4582 (95% probability interval, $4084-$5080; P < .001). Cost savings in the model were driven by the adjusted relative risk of the web-based intervention, probability of a COPD-related acute exacerbation, rate of hospitalization, probability of hospitalization, and cost of hospitalization.

CONCLUSIONS

A pedometer-based, web-mediated physical activity intervention yielded substantial cost savings. Increased implementation of the intervention could markedly reduce the economic burden of COPD for payers and patients.

"Can Do, Do Do" Quadrants and 6-Year All-Cause Mortality in Patients With COPD

BACKGROUND

Physical capacity (PC; "can do") and physical activity (PA; "do do") are prognostic indicators in COPD and can be used to subdivide patients with COPD into four exclusive subgroups (the so-called "can do, do do" quadrants). This concept may be useful to understand better the impact of PC and PA on all-cause mortality in patients with COPD.

RESEARCH QUESTION

What is the 6-year all-cause mortality risk of the "can do, do do" quadrants of patients with COPD?

STUDY DESIGN AND METHODS

This retrospective study used data from patients with COPD who underwent a comprehensive assessment at their first-ever outpatient consultation. PC was assessed using the 6-min walk distance and physical activity was assessed using an accelerometer (steps per day). All-cause mortality data were obtained from the Municipal Personal Records Database. Receiver operating characteristic curves were used to determine threshold values for PC and PA to predict 6-year all-cause mortality. Using the derived threshold values, male and female patients were divided into the four "can do, do do" quadrants.

RESULTS

Data from 829 patients were used for analyses. Best discriminatory values for 6-year mortality were 404 m and 4,125 steps/day for men and 394 m and 4,005 steps/day for women. During a median follow-up of 55 months (interquartile range, 37-71 months), 129 patients (15.6%) died. After controlling for established prognostic factors, patients in the "can do, don't do" quadrant and "can do, do do" quadrant showed significantly lower mortality risk compared with patients in the "can't do, don't do" quadrant: hazard ratios of 0.36 (95% CI, 0.14-0.93) and 0.24 (95% CI, 0.09-0.61) for men and 0.37 (95% CI, 0.38-0.99) and 0.29 (95% CI, 0.10-0.87) for women, respectively. No significant differences were found between the "can't do, do do" and "can't do, don't do" quadrants.

INTERPRETATION

Patients with COPD with a preserved PC seem to have a significantly lower 6-year mortality risk compared with patients with a decreased PC, regardless of physical activity level.

Physical Activity, Exercise Capacity, and Body Composition in U.S. Veterans with Chronic Obstructive Pulmonary Disease (COPD)

RATIONALE

Differences in body composition may contribute to variability in exercise capacity (EC) and physical activity (PA) in chronic obstructive pulmonary disease (COPD). Most studies have employed bioimpedance-based surrogates of muscle (lean) mass; relatively few studies have included consideration of fat mass and limited studies have been performed using dual X-ray absorptiometry (DXA)-assessed body composition.

OBJECTIVE

To determine whether DXA-assessed muscle (lean) and fat mass exhibit differential correlations with EC and PA in COPD Methods: US Veterans with COPD (defined as FEV1/FVC<0.7 or emphysema on clinical chest computed tomography) had DXA-assessed body composition, EC (6-minute walk distance; 6MWD), objective PA (average daily step counts), and self-reported PA measured at enrollment. Associations between EC, PA, and body composition were examined using Spearman correlations and multivariable models adjusted a priori for age, sex, race, and lung function.

RESULTS

Subjects (n=98) were predominantly white (88%), obese (mean BMI 30.2±6.2), and male, (94%) with a mean age (±SD) of 69.9±7.9 years and moderate airflow obstruction (mean FEV1% 68±20). Modest inverse correlations between EC and PA with fat mass were observed (Spearman's rho range [-0.20]-[-0.34]) while measures of muscle (lean) mass were not significantly associated with EC or PA. The appendicular skeletal muscle (ASM)-to-weight ratio, which considers both muscle (lean) and fat mass, was consistently associated with EC (8.4 [95%CI=2.9-13.8] meter increase on 6MWD per 1% increase in ASM-to-weight ratio), objective PA (194.8 [95%CI=15.2-374.4] steps per day per 1% increase in ASM-to-weight ratio), and self-reported PA in multivariable-adjusted models.

CONCLUSION

DXA-assessed body composition measures which include consideration of both lean and fat mass are associated with cross-sectional EC and PA in COPD populations. Clinical trial registered at ClinicalTrials.gov (NCT02099799).

Digital healthcare in COPD management: a narrative review on the advantages, pitfalls, and need for further research

Chronic obstructive pulmonary disease (COPD) remains a leading cause of morbidity and mortality despite current treatment strategies which focus on smoking cessation, pulmonary rehabilitation, and symptomatic relief. A focus of COPD care is to encourage self-management, particularly during COVID-19, where much face-to-face care has been reduced or ceased. Digital health solutions may offer affordable and scalable solutions to support COPD patient education and self-management, such solutions could improve clinical outcomes and expand service reach for limited additional cost. However, optimal ways to deliver digital medicine are still in development, and there are a number of important considerations for clinicians, commissioners, and patients to ensure successful implementation of digitally augmented care. In this narrative review, we discuss advantages, pitfalls, and future prospects of digital healthcare, which offer a variety of tools including self-management plans, education videos, inhaler training videos, feedback to patients and healthcare professionals (HCPs), exacerbation monitoring, and pulmonary rehabilitation. We discuss the key issues with sustaining patient and HCP engagement and limiting attrition of use, interoperability with devices, integration into healthcare systems, and ensuring inclusivity and accessibility. We explore the essential areas of research beyond determining safety and efficacy to understand the acceptability of digital healthcare solutions to patients, clinicians, and healthcare systems, and hence ways to improve this and sustain engagement. Finally, we explore the regulatory challenges to ensure quality and engagement and effective integration into current healthcare systems and care pathways, while maintaining patients’ autonomy and privacy. Understanding and addressing these issues and successful incorporation of an acceptable, simple, scalable, affordable, and future-proof digital solution into healthcare systems could help remodel global chronic disease management and fractured healthcare systems to provide best patient care and optimisation of healthcare resources to meet the global burden and unmet clinical need of COPD.

Impact of Seasonality on Physical Activity: A Systematic Review

BACKGROUND

The purpose of this study was to collect and analyze the available scientific evidence of the impact of seasonality on physical activity (PA). PA refers to walking, biking, sports and/or active recreation.

METHODS

The search was performed in the following databases: PubMed, PEDro, Cochrane and Embase. All publications from January 2015 to September 2020 assessing seasonal variations on physical activity development in adults were selected.

RESULTS

A total of 1159 articles were identified, of which 26 fulfilled the selection criteria involving 9300 participants from 18 different countries. The results obtained suggest that seasonality affects PA independently of the countries, pathologies of the participants and the tool to collect PA information.

CONCLUSIONS

PA level varies across the seasons, with higher PA level in summer compared with other seasons, especially in winter. Sedentary behavior follows the opposite trend. Impact of seasonality variations should be considered in clinical research involving PA as a primary outcome as well as in interventions on PA promotion.

Association between behavioral phenotypes and sustained use of smartphones and wearable devices to remotely monitor physical activity

Smartphones and wearable devices can be used to remotely monitor health behaviors, but little is known about how individual characteristics influence sustained use of these devices. Leveraging data on baseline activity levels and demographic, behavioral, and psychosocial traits, we used latent class analysis to identify behavioral phenotypes among participants randomized to track physical activity using a smartphone or wearable device for 6 months following hospital discharge. Four phenotypes were identified: (1) more agreeable and conscientious; (2) more active, social, and motivated; (3) more risk-taking and less supported; and (4) less active, social, and risk-taking. We found that duration and consistency of device use differed by phenotype for wearables, but not smartphones. Additionally, "at-risk" phenotypes 3 and 4 were more likely to discontinue use of a wearable device than a smartphone, while activity monitoring in phenotypes 1 and 2 did not differ by device type. These findings could help to better target remote-monitoring interventions for hospitalized patients.

Burden and Unmet Needs with Portable Oxygen in Patients on Long-Term Oxygen Therapy

Rationale: Over 1.5 million Americans receive long-term oxygen therapy (LTOT) for the treatment of chronic hypoxemia to optimize functional status and quality of life. However, current portable oxygen equipment, including portable gas tanks (GTs), portable liquid tanks (LTs), and portable oxygen concentrators (POCs), each have limitations that can hinder patient mobility and daily activities. Objectives: To examine patient experiences with portable oxygen to guide equipment innovation and thereby improve patient care on oxygen therapy. Methods: The burden and unmet needs with portable oxygen equipment were assessed in 836 LTOT patients with chronic lung disease (chronic obstructive pulmonary disease [COPD], interstitial lung disease, and pulmonary hypertension) through an online survey. The survey included a combination of multiple-choice, Likert-scale, short-answer, and open-ended questions. Distribution was achieved through patient support organizations, including the U.S. COPD Coalition, the Pulmonary Fibrosis Foundation, and the Pulmonary Hypertension Association. Results: Improvements in portability were ranked as the highest priority by patients across all equipment types, followed by increases in the duration of oxygen supply for GTs, accessibility for LTs, and flow capabilities for POCs. All device types were found to be burdensome, with the greatest burden among GT users, 51% of whom characterized GT use as "strenuous" or "extremely strenuous" (high burden). POCs ranked as the most common (61%) and least burdensome devices; however, 29% of POC users still reported a high associated burden. Forty-seven percent of POC respondents described using a POC despite it not meeting their oxygen needs to benefit from advantages over alternative equipment. Among non-POC users, limited oxygen flow rate capabilities and cost were the top reasons preventing POC use. Conclusions: Although improvements have been made to portable oxygen equipment, this study highlights the burden that remains and reveals a clear need for advances in technology to improve the functional status and quality of life of portable LTOT users.

Molecular markers of aging, exercise capacity, & physical activity in COPD

BACKGROUND

Exercise capacity (EC) and physical activity (PA) are independent, potentially modifiable predictors of clinical outcomes in COPD. Molecular measures of biological age may help characterize variability in EC and PA observed among COPD patients.

METHODS

Veterans with COPD (FEV₁/FVC<0.7 or emphysema on chest computed tomography) enrolled in 2 cohorts at VA Boston completed questionnaires, a 6-min walk distance (6MWD) for EC, and blood collection at enrollment. PA data (average daily step count) was collected using an HJ-720 ITC pedometer over ≥5 days. A subset of subjects returned for repeat assessment after 12 weeks. DNA methylation data was generated using the HumanMethylationEPIC platform; epigenetic estimates of biological age and age acceleration were generated using established algorithms. Multivariable models examined the associations between biological age, 6MWD, PA and future acute exacerbations (AEs), adjusting for chronological age, sex, race, smoking status, pack-years, body mass index, cohort, and estimated cell counts.

RESULTS

Subjects (n = 269) were predominantly male (98.5%), white (92.9%), and elderly (70.6 ± 8.5 years) with average FEV₁% of 57.7 ± 21.1, 6MWD of 374.3 ± 93.5 m, and daily steps of 3043.4 ± 2374 at baseline. In adjusted models, multiple measures of baseline epigenetic age and age acceleration were inversely associated with 6MWD; only GrimAge was inversely associated with PA. Longitudinal change in Hannum-Age was inversely associated with change in EC at 12 weeks (n = 94). No measures of biological age were significantly associated with prospective AEs over 1.3 ± 0.3 years.

CONCLUSIONS

Epigenetic measures of biological age are independent predictors of EC and PA, but not AEs, among individuals with COPD.

Active wearable device utilization improved physical performance and IGF-1 among community-dwelling middle-aged and older adults: a 12-month prospective cohort study

Wearable devices provide real-time and patient-powered data that enable the development of personalized health promotion and management programs. This study aimed to explore the clinical benefits of using the wearable device and to examine associated factors, utilization patterns on health status. 319 community-living adults aged 50-85 years were enrolled and clinically followed for 12 months. Participants were categorized into 3 groups based on the wearable device utilization patterns (active: >30 days of use, non-active: <3 days of use, usual: 3-30 days of use). 128 (40.1%) and 98(30.7%) were active and usual wearable device users, and no significant differences in the baseline demographic characteristics and functional status were noted across groups. Higher cognitive performance was significantly associated with the wearable device use (OR: 1.3,95%CI: 1.1-1.5, p=0.005). Multivariable linear regression showed that 0.16 m/s increase in walking speed among active users, which was significantly higher than non-active users (p=0.034). Compared to usual users, active users had higher average daily, weekday, and holiday step counts. The walking speed increased for 0.03 m/s when participants walked 1,000 more daily step counts (p=0.020). Active use of wearable devices substantially increased walking speed, which suggested better functional outcomes and survival benefits in the future.

Pain in Veterans with COPD: relationship with physical activity and exercise capacity

BACKGROUND

Pain is a common but underappreciated symptom experienced by people with Chronic Obstructive Pulmonary Disease (COPD). The relationships between pain and physical activity (PA) and exercise capacity are poorly understood.

METHODS

This retrospective secondary analysis includes three cohorts of Veterans with COPD who participated in longitudinal studies evaluating PA and exercise capacity with objective measures of daily step counts and 6-min walk test (6MWT) distance, respectively. Pain was assessed using the bodily pain domain of the Veterans RAND-36. In two cohorts, participants were randomly assigned to a web-based, pedometer-mediated PA intervention which has previously been demonstrated to improve PA.

RESULTS

Three-hundred and seventy-three (373) unique study participants were included in this analysis. Eighty-three percent (n = 311) of the population reported at least mild pain and/or at least a little bit of interference due to pain at baseline. Cross-sectionally, greater bodily pain was associated with lower 6MWT distance (β = 0.51; 95% CI 0.20, 0.82; p = 0.0013). Longitudinally, worsening bodily pain was associated with a decline in 6MWT distance (β = 0.30; 95% CI 0.03, 0.58; p = 0.0312). There was no association between baseline bodily pain and baseline daily step counts, baseline bodily pain and change in PA, or change in bodily pain and change in PA. Compared to usual care, our PA intervention improved bodily pain scores (β = 6.17; 95% CI 1.84, 10.45; p = 0.0054). Bodily pain scores did not affect the impact of the intervention on daily step counts.

CONCLUSION

Pain is highly prevalent and significantly associated with lower exercise capacity among Veterans with COPD. Worsening pain co-occurred with decline in exercise capacity but not PA. Our intervention reduced pain, although pain did not affect the impact of the intervention on PA.

Co-occurrence of pain and dyspnea in Veterans with COPD: Relationship to functional status and a pilot study of neural correlates using structural and functional magnetic resonance imaging

Persons with COPD experience co-occurring dyspnea and pain. Little is known about the relationship between symptom co-occurrence with physical activity (PA) and exercise. Novel diagnostic tools are needed for accurate symptom discrimination. In this secondary analysis, we examined relationships between baseline assessments of pain, dyspnea, objectively measured PA, and exercise capacity in persons with COPD who previously enrolled in three PA studies. Pain was assessed with the bodily pain domain of the Veterans RAND-36 (VR-36), and dyspnea with the modified Medical Research Council (mMRC) scale. Average daily step count was assessed with the Omron HJ-720ITC or FitBit Zip pedometer, and exercise capacity with 6-minute walk test (6MWT). We also conducted a pilot neuroimaging study. Neuroimaging data were acquired on a Siemens 3-Tesla Magnetom Prisma^fit whole-body scanner. Analysis of variance assessed trends in daily step count and 6MWT distance across categories of co-occurring pain and dyspnea. General linear models examined relationships between cortical thickness and resting state functional connectivity (fc) with symptoms and functional status. In 373 Veterans, 98% were male with mean age 70.5± 8.3 years and FEV₁% predicted 59 ± 21%. Compared to those with no co-occurrence of pain and dyspnea, those with co-occurrence walked 1,291–1,444 fewer steps per day and had an 80–85 m lower 6MWT distance. Ten males participated in the pilot neuroimaging study. Predominant findings were that lower cortical thickness and greater fc were associated with higher pain and dyspnea, p<0.05. Greater cortical thickness and lower fc were associated with higher daily step count and 6MWT distance, p<0.05. Regional patterns of associations differed for pain and dyspnea, suggesting that cortical thickness and fc may discriminate symptoms. Co-occurring dyspnea and pain in COPD are associated with significant reductions in PA and exercise capacity. It may be feasible for neuroimaging markers to discriminate between pain and dyspnea.

Exploring Tai Chi Exercise and Mind-Body Breathing in Patients with COPD in a Randomized Controlled Feasibility Trial

In this pilot feasibility randomized controlled trial, participants with moderate to severe COPD were randomized to a 12-week tai chi or MBB intervention. Participants were assessed at baseline, 12 weeks, and 24 weeks. Feasibility, as assessed by intervention adherence, was the primary outcome. We also estimated preliminary between-group differences in COPD symptoms and health-related quality of life, cognitive-emotional function, and functional status across three timepoints: baseline, 12, and 24 weeks. A total of 92 participants were randomized 2:1 to tai chi (n = 61) or MBB (n = 31). The overall group adherence in the first 12 weeks was 62% in tai chi and 75% in MBB. From baseline to 12 weeks, tai chi demonstrated greater improvements in depressive symptoms (Cohen's d effect size (ES) = -.53; adj mean diff = -2.31 [-5.7, 1.07]), 6-minute walk test distance (ES = .47; adj mean diff = 62.04 [2.85, 121.22]), social support (ES = .36; adj mean diff = .19 [-0.11, 0.49]) and chair stand (ES = .44; adj mean diff = .91 [-0.05, 1.86]). Only improvements in social support were maintained at 24-week follow-up. Tai chi and MBB are feasible for individuals with COPD. Preliminary effects suggest that while our mindful breathing intervention may not be sufficient to impact outcomes, tai chi may result in short-term benefits in mood, social support and functional capacity. More work is needed to better understand mindful breathing for COPD and to examine methods for maintaining improvements from tai chi over time.Supplemental data for this article is available online at https://doi.org/10.1080/15412555.2021.1928037 .

Sociodemographic Characteristics and Physical Activity in Patients with COPD: A 3-Month Cohort Study

Decreased physical activity (PA) is associated with morbidity and mortality in COPD patients. In this secondary analysis of data from a 12-week longitudinal study, we describe factors associated with PA in COPD. Participants completed the Physical Activity Checklist (PAC) daily for a 7- to 8-day period. PA was measured monthly using the Physical Activity Scale for the Elderly (PASE). At three different time points, daily step count was measured for one week with an Omron HJ-720ITC pedometer. The 35 participants were primarily male (94%) and White (91%), with an average age of 66.5 years and FEV₁ 44.9% predicted. Common activities reported on the PAC were walking (93%), preparing a meal (89%), and traveling by vehicle (96%). PA measured by both PASE score (p = 0.01) and average daily step count (p = 0.04) decreased during follow-up. In repeated measures multivariable modeling, participants living with others had a higher daily step count (ß = 942 steps, p = 0.01) and better PASE scores (ß = 46.4, p < 0.001). Older age was associated with decreased step count (ß = -77 steps, p < 0.001) whereas White race was associated with lower PASE scores (ß = -55.4, p < 0.001) compared to non-White race. Other demographic factors, quality of life, and medications were not associated with PA. A better understanding of the role of social networks and social support may help develop interventions to improve PA in COPD.

Development of a Novel Intervention (Mindful Steps) to Promote Long-Term Walking Behavior in Chronic Cardiopulmonary Disease: Protocol for a Randomized Controlled Trial

Background

Despite current rehabilitation programs, long-term engagement in physical activity remains a significant challenge for patients with chronic obstructive pulmonary disease (COPD) and heart failure (HF). Novel strategies to promote physical activity in these populations are greatly needed. Emerging literature on the benefits of both mind–body interventions and web-based interventions provide the rationale for the development of the Mindful Steps intervention for increasing walking behavior.

Objective

This study aims to develop a novel multimodal mind–body exercise intervention through adaptation of an existing web-based physical activity intervention and incorporation of mind–body exercise, and to pilot test the delivery of the new intervention, Mindful Steps, in a randomized controlled feasibility trial in older adults with COPD and/or HF.

Methods

In phase 1, guided by a theoretical conceptual model and review of the literature on facilitators and barriers of physical activity in COPD and HF, we convened an expert panel of researchers, mind–body practitioners, and clinicians to inform development of the novel, multimodal intervention. In phase 2, we are conducting a pilot randomized controlled feasibility trial of the Mindful Steps intervention that includes in-person mind–body exercise classes, an educational website, online mind–body videos, and a pedometer with step-count feedback and goals to increase walking behavior in patients with COPD and/or HF. Outcomes include feasibility measures as well as patient-centered measures.

Results

The study is currently ongoing. Phase 1 intervention development was completed in March 2019, and phase 2 data collection began in April 2019.

Conclusions

Through the integration of components from a web-based physical activity intervention and mind–body exercise, we created a novel, multimodal program to impact long-term physical activity engagement for individuals with COPD and HF. This developmental work and pilot study will provide valuable information needed to design a future clinical trial assessing efficacy of this multimodal approach.

Trial Registration

ClinicalTrials.gov NCT03003780; https://clinicaltrials.gov/ct2/show/NCT03003780

International Registered Report Identifier (IRRID)

DERR1-10.2196/27826

Improving mobility and participation of older people with vertigo, dizziness and balance disorders in primary care using a care pathway: feasibility study and process evaluation

BACKGROUND

Community-dwelling older people are frequently affected by vertigo, dizziness and balance disorders (VDB). We previously developed a care pathway (CPW) to improve their mobility and participation by offering standardized approaches for general practitioners (GPs) and physical therapists (PTs). We aimed to assess the feasibility of the intervention, its implementation strategy and the study procedures in preparation for the subsequent main trial.

METHODS

This 12-week prospective cohort feasibility study was accompanied by a process evaluation designed according to the UK Medical Research Council's Guidance for developing and evaluating complex interventions. Patients with VDB (≥65 years), GPs and PTs in primary care were included. The intervention consisted of a diagnostic screening checklist for GPs and a guide for PTs. The implementation strategy included specific educational trainings and a telephone helpline. Data for mixed-method process evaluation were collected via standardized questionnaires, field notes and qualitative interviews. Quantitative data were analysed using descriptive statistics, qualitative data using content analysis.

RESULTS

A total of five GP practices (seven single GPs), 10 PT practices and 22 patients were included in the study. The recruitment of GPs and patients was challenging (response rates: GP practices: 28%, PT practices: 39%). Ninety-one percent of the patients and all health professionals completed the study. The health professionals responded well to the educational trainings; the utilization of the telephone helpline was low (one call each from GPs and PTs). Familiarisation with the routine of application of the intervention and positive attitudes were emphasized as facilitators of the implementation of the intervention, whereas a lack of time was mentioned as a barrier. Despite difficulties in the GPs' adherence to the intervention protocol, the GPs, PTs and patients saw benefit in the intervention. The patients' treatment adherence to physical therapy was good. There were minor issues in data collection, but no unintended consequences.

CONCLUSION

Although the process evaluation provided good support for the feasibility of study procedures, the intervention and its implementation strategy, we identified a need for improvement in recruitment of participants, the GP intervention part and the data collection procedures. The findings will inform the main trial to test the interventions effectiveness in a cluster RCT.

TRIAL REGISTRATION

Projektdatenbank Versorgungsforschung Deutschland (German registry Health Services Research) VfD_MobilE-PHY_17_003910, date of registration: 30.11.2017; Deutsches Register Klinischer Studien (German Clinical Trials Register) DRKS00022918, date of registration: 03.09.2020 (retrospectively registered).

Exacerbations and Changes in Physical Activity and Sedentary Behaviour in Patients with Bronchiectasis after 1 Year

Background: Low physical activity and high sedentary behaviour in patients with bronchiectasis are associated with hospitalisation over one year. However, the factors associated with longitudinal changes in physical activity and sedentary behaviour have not been explored. We aimed to identify clinical and sociodemographic characteristics related to a change in physical activity and sedentary behaviour in patients with bronchiectasis after one year. Methods: This was a prospective observational study during which physical activity measurements were recorded using a SenseWear Armband for one week at baseline and at one year. At each assessment point, patients were classified as active or inactive (measured as steps per day) and as sedentary or not sedentary (measured as sedentary time). Results: 53 patients with bronchiectasis were analysed, and after one year, 18 (34%) had worse activity and sedentary levels. Specifically, 10 patients became inactive and sedentary. Multivariable analysis showed that the number of exacerbations during the follow-up period was the only outcome independently associated with change to higher inactivity and sedentary behaviour (odds ratio (OR), 2.19; 95% CI, 1.12 to 4.28). Conclusions: The number of exacerbations in patients with bronchiectasis was associated with changes in physical activity and sedentary behaviour. Exacerbation prevention may appear as a key factor in relation to physical activity and sedentary behaviour in patients with bronchiectasis.

Physical activity in hemodialysis patients on nondialysis and dialysis days: Prospective observational study

INTRODUCTION

The physical decline in patients with end-stage kidney disease (ESKD) is associated with morbidity and mortality. Prior studies have attempted to promote physical activity at the time of dialysis; however, physical activity patterns on the nondialysis days are unknown. This study aimed to quantify physical activity on dialysis and nondialysis days in hemodialysis patients using a wearable actigraph.

METHODS

In this prospective study, subjects receiving hemodialysis were recruited from two outpatient dialysis units in urban San Diego and rural Imperial County, CA, between March 2018 and April 2019. Key inclusion criteria included: (1) receiving thrice weekly hemodialysis for ≥3 months, (2) age ≥ 18 years, and (3) able to walk with or without assistive devices. All participants wore a Fitbit Charge 2 tracker for a minimum of 4 weeks. The primary outcome was the number of steps per day. Each participant completed the Physical Activity Questionnaire, the Patient Health Questionnaire (PHQ)-9, the PROMIS Short form Fatigue Questionnaire at baseline, and the Participant Technology Experience Questionnaire at day 7 after study enrolment.

FINDINGS

Of the 52 recruited, 45 participants (urban = 25; rural = 20) completed the study. The mean age was 61 ± 15 years, 42% were women, 64% were Hispanic, and the mean dialysis vintage was 4.4 ± 3.0 years. For those with valid Fitbit data (defined as ≥10 hours of wear per day) for 28 days (n = 45), participants walked an average of 3688 steps per day, and 73% of participants were sedentary (<5000 steps/day). Participants aged >80 years were less active than younger (age < 65 years) participants (1232 vs. 4529 steps, P = 0.01). There were no statistical differences between the groups when stratified by gender (women vs. men [2817 vs. 4324 steps, respectively]), urbanicity (rural vs. urban dialysis unit [3141 vs. 4123 steps, respectively]), and dialysis/nondialysis day (3177 vs. 4133 steps, respectively). Due to the small sample size, we also calculated effect sizes. The effect size was medium for the gender differences (cohen's d = 0.57) and small to medium for urbanicity and dialysis/nondialysis day (d = 0.37 and d = 0.33, respectively). We found no association between physical activity and self-reported depression and fatigue scale. The majority of participants (62%, 28/45) found the Fitbit tracker easy to wear and comfortable.

DISCUSSION

ESKD participants receiving hemodialysis are frequently sedentary, and differences appear more pronounced in older patients. These findings may assist in designing patient-centered interventions to increase physical activity among hemodialysis patients.

Can Technology-Based Physical Activity Programs for Chronic Obstructive Pulmonary Disease Be Cost-Effective?

Objective: To evaluate the cost-effectiveness of a technology-based physical activity (PA) intervention for chronic obstructive pulmonary disease (COPD). Design: A secondary data analysis was performed from a randomized controlled trial in COPD of an activity monitor alone or an activity monitor plus a web-based PA intervention. Models estimated cost per quality-adjusted life year (QALY) and incremental cost-effectiveness ratios (ICERs) compared with usual care. Results: The estimated ICER for both groups was below the willingness-to-pay threshold of $50,000/QALY (activity monitor alone = $10,437/QALY; website plus activity monitor intervention = $13,065/QALY). A probabilistic simulation estimated 76% of the activity monitor-alone group and 78% of the intervention group simulations to be cost-effective. Conclusion(s): Both the activity monitor-alone group and the activity monitor plus website group were cost-effective at the base case by using conventional willingness-to-pay thresholds. Further research would benefit from a more direct estimate of health utilities and downstream health care costs. Clinical Trials.gov NCT01102777.

Sit-to-stand tests in patients hospitalised for chronic obstructive pulmonary disease exacerbation: association with pulmonary function tests and risk of future exacerbations

Background/Aims

The sit-to-stand test is a quick and cost-effective measure of exercise tolerance and lower body strength. The literature focuses on its use in stable patients with chronic obstructive pulmonary disease. This study in patients hospitalised for chronic obstructive pulmonary disease exacerbation aimed to investigate possible associations of the sit-to-stand test with pulmonary function and risk of future acute exacerbations.

Methods

This study was conducted on a sample of 22 patients with chronic obstructive pulmonary disease. Participants' clinical details were recorded before they undertook spirometry, 30-second and five-repetition sit-to-stand tests. Participants were assessed via a structured telephone interview for the occurrence of acute exacerbation events in the 12 months following discharge.

Results

Patients were classified based on the presence or absence of acute exacerbations of chronic obstructive pulmonary disease over 12 months. A negative correlation was observed between five-repetition sit-to-stand test performance time and number of repetitions during the 30-second sit-to-stand test; longer sit-to-stand times and fewer repetitions were observed in patients who experienced exacerbations during follow up. The 30-second sit-to-stand test repetitions correlated positively with forced expiratory volume in 1 second (FEV1). Five-repetition sit-to-stand test performance correlated negatively with FEV1, FEV1% predicted, forced vital capacity and FEV1/forced vital capacity ratio. From the various exercise parameters, five-repetition sit-to-stand test performance time demonstrated a moderate ability to predict exacerbations.

Conclusions

This study is the first to focus on the use of the sit-to-stand tests in inpatients with acute exacerbation of chronic obstructive pulmonary disease. There was a significant correlation between the 30-second sit-to-stand test and five-repetition sit-to-stand test results. Both tests were associated with pulmonary function indices and risk of future chronic obstructive pulmonary disease exacerbations.

BEAM study (Breathing, Education, Awareness, Movement): a randomised controlled feasibility trial of tai chi exercise in patients with COPD

BACKGROUND

Despite therapeutic advances, the management of chronic obstructive pulmonary disease (COPD) remains complex. There is growing interest in multidimensional, mind-body exercises to improve both physical and psychosocial aspects of COPD burden. Few US data are available in this population on tai chi (TC) a mind-body exercise incorporating physical activity, breathing and mindful awareness. We explored feasibility and preliminary efficacy of TC in COPD in an US academic medical setting.

METHODS

Patients with COPD Global Obstructive Lung Disease (GOLD) stages 2-4 were randomised to a 12-week TC programme or education control. At 12 weeks, those in TC were randomised again to continue in maintenance classes or not to further explore optimal duration. All groups were followed to 24 weeks. Feasibility/safety parameters were analysed descriptively. Preliminary between-group differences were estimated in symptoms (dyspnoea, fatigue), health-related quality-of-life (Chronic Respiratory Questionnaire CRQ), cognitive-emotional measures (mood, COPD self-efficacy) and functional status (6 min walk test, lower body strength, flexibility, physical activity).

RESULTS

Ninety-two subjects were randomised (N=61 TC, N=31 education). Mean age was 68±8 years, 66% male, mean forced expiratory volume in 1 s % predicted 57±13, 28% were GOLD stage 3-4. Overall retention was 85%. Nineteen adverse events occurred, most being study-unrelated COPD exacerbations. From baseline to 12 weeks, there were between-group improvements favouring TC, in CRQ-total (Cohen's d effect size (ES)=0.46; adj mean diff (AMD)=0.31), CRQ-emotion (ES=0.54; AMD=0.49), Centre for Epidemiologic Studies Depression (ES=-0.37; AMD=2.39) and Patient-Reported Outcome Measurement Information System (PROMIS)-fatigue (ES=-0.34; AMD=-0.17). From baseline to 24 weeks, there was an improvement favouring TC in CRQ-dyspnoea (ES=0.41; AMD=0.46). Among TC participants, there was a positive effect of maintenance classes on self-efficacy (ES=-0.69; AMD=-0.40), 6 min walk (ES=0.56; AMD=49.26 feet), PROMIS-fatigue (ES=-0.41; AMD=-0.28) and chair stand (0.43; AMD=0.56).

CONCLUSION

TC in patients with COPD is feasible and safe. Preliminary analyses support a potential modest role in improving quality-of-life, cognitive-emotional health and function that should be further studied.

TRIAL REGISTRATION NUMBER

NCT01551953.

IRB REFERENCE

BIDMC 2010P-000412; VA 2540.

Data Reproducibility and Effectiveness of Bronchodilators for Improving Physical Activity in COPD Patients

Increasing physical activity (PA) in patients with chronic obstructive pulmonary disease (COPD) is an important issue, however, the effect of bronchodilators on PA is still controversial. The indicators of PA, as measured by an accelerometer, can easily fluctuate based on several factors, which might cause inconsistent results. In this review, we listed the indicators of PA and the factors influencing the reproducibility of indicators of PA, and reviewed reports in which the effects of bronchodilators on PA were evaluated by an accelerometer. Then, we investigated the association between the processing of influencing factors and the effectiveness of bronchodilators for improving the PA of COPD patients. Fifteen reports were extracted using the PubMed database. In all seven reports in which adjustment was performed for at least two of four influencing factors (non-wear time, data from days with special behavior, environmental factors, and number of valid days required to obtain reproducible data), bronchodilators showed beneficial effects on PA. No adjustment was made for any of these factors in any of the four bronchodilator-ineffective reports. This suggests that the processing of influencing factors to secure reproducibility might affect the results regarding the effectiveness of bronchodilators for improving PA in COPD patients.

The Correlation of Sit-to-Stand Tests with COPD Assessment Test and GOLD Staging Classification

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) ABCD classification tool has been used to assess the symptom burden and exacerbation risk of patients with chronic obstructive pulmonary disease (COPD). An area requiring further exploration is the relationship between the GOLD classification's basic components and the measurements acquired by Sit-to-Stand tests (STST). We aimed to study the relationship between STST and the component of the GOLD classification tool. This study was conducted on a sample of 42 COPD subjects with patient history, COPD assessment test (CAT) and spirometry. 5STST performance time and the number 30s-STST repetitions showed differences of statistical significance in COPD subjects considered to be more symptomatic and in subjects with high risk of future exacerbations. Both STSTs correlated significantly with forced expiratory volume in one second % predicted (FEV1%), CAT, number of acute exacerbations in the past year and number of hospitalized exacerbations in the past year. STST performance correlates significantly with items of the CAT questionnaire that assess breathlessness, limitation of activities, confidence and lack of energy. Using multivariate analysis, age, FEV1% and CAT score manifested the strongest negative association with STST performance. 5STST performance time and the number 30s-STST repetitions in COPD patients correlates with the level of symptoms and the risk of future exacerbations that define groups A-D based on GOLD 2018 classification tool (at the time of data acquisition). The correlation of STST performance with CAT score involves specific items of the questionnaire that assess breathlessness, limitation of activities, confidence and lack of energy.

Frailty in Chronic Obstructive Pulmonary Disease and Risk of Exacerbations and Hospitalizations

Background

Frailty is a complex clinical syndrome associated with vulnerability to adverse health outcomes. While frailty is thought to be common in chronic obstructive pulmonary disease (COPD), the relationship between frailty and COPD-related outcomes such as risk of acute exacerbations of COPD (AE-COPD) and hospitalizations is unclear.

Purpose

To examine the association between physical frailty and risk of acute exacerbations, hospitalizations, and mortality in patients with COPD.

Methods

A longitudinal analysis of data from a cohort of 280 participants was performed. Baseline frailty measures included exhaustion, weakness, low activity, slowness, and undernutrition. Outcome measures included AE-COPD, hospitalizations, and mortality over 2 years. Negative binomial regression and Cox proportional hazard modeling were used.

Results

Sixty-two percent of the study population met criteria for pre-frail and 23% were frail. In adjusted analyses, the frailty syndrome was not associated with COPD exacerbations. However, among the individual components of the frailty syndrome, weakness measured by handgrip strength was associated with increased risk of COPD exacerbations (IRR 1.46, 95% CI 1.09–1.97). The frailty phenotype was not associated with all-cause hospitalizations but was associated with increased risk of non-COPD-related hospitalizations.

Conclusion

This longitudinal cohort study shows that a high proportion of patients with COPD are pre-frail or frail. The frailty phenotype was associated with an increased risk of non-COPD hospitalizations but not with all-cause hospitalizations or COPD exacerbations. Among the individual frailty components, low handgrip strength was associated with increased risk of COPD exacerbations over a 2-year period. Measuring handgrip strength may identify COPD patients who could benefit from programs to reduce COPD exacerbations.

The Relationship Between Morning Symptoms and the Risk of Future Exacerbations in COPD

Background

The morning is the most troublesome time of day for patients with chronic obstructive pulmonary disease (COPD). However, the association of morning symptoms and COPD exacerbations in longitudinal follow-up has not been studied. In this study, we mainly aimed to investigate the relationship between morning symptoms and exacerbations over a one-year follow-up period. And the secondary aim was an investigation of the association between morning symptoms and baseline clinical features.

Patients and Methods

Ninety-two patients with stable COPD provided the baseline information. Morning symptoms were assessed with the Chinese version of Chronic Obstructive Pulmonary Disease Morning Symptom Diary (Ch-COPD-MSD); the median morning symptoms score was used as a cut-off to separate the study cohort in two groups. Modified Medical Research Council (mMRC), COPD assessment test (CAT), and Clinical COPD Questionnaire (CCQ) were used and exacerbation history of the previous year was recorded. Seventy-eight patients (84.8%) completed the longitudinal follow-up of exacerbations.

Results

The median morning symptoms score was 30 in stable COPD patients. Morning symptoms severity was different between COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) groups (p<0.001). Patients with high morning symptoms (score > 30) had higher scores of mMRC, CAT, and CCQ (p< 0.05). CAT score was an independent risk factor of morning symptoms. During follow-up, 41% of patients experienced ≥1 exacerbation. The frequency of severe exacerbations was higher in patients with high morning symptoms compared to patients with low morning symptoms (p<0.005). The Ch-COPD-MSD score could predict future severe exacerbations; the area under the ROC curve was 0.751 (95% CI: 0.633-0.868, p=0.002).

Conclusion

Worse health status and more dyspnea symptom were associated with increased severity of morning symptoms. Morning symptoms were most strongly related to future severe exacerbations and could predict future exacerbations in patients with COPD.

Physical activity in COPD: Minimal clinically important difference for medical events

Estimates of the minimal clinically important difference (MCID) for physical activity (PA) in chronic obstructive pulmonary disease (COPD) are needed. The objective is to provide an anchor-based estimate of the MCID for daily step count. PA was promoted in persons with COPD using a pedometer (Omron HJ-720ITC) alone or a pedometer plus interactive website for 3 months. Participants wore the pedometer daily and received phone calls monthly to ascertain medical events. Medical events were counted when a participant self-reported that he/she had (1) worsening of breathing, (2) change to breathing medications, (3) medical care from an emergency room for any reason, or (4) hospitalization for any reason. Generalized linear regression models assessed daily step count as change at the end of study and averaged over the 15, 31, or 61 days centered on the event, in those with an event compared to those without one. All categories of events carried equal weight in the analyses. We studied 93 persons, 46 of whom had an event. Participants who experienced an event had a decrease of 1086 (95% confidence interval (CI): −2124 to −48) or 887 (95% CI: −2030 to 257) steps/day in the pedometer plus website or pedometer alone groups, respectively, compared to those without one. In the days centered on an event, participants who had an event experienced a decrease of 882–983 steps/day (pedometer plus website) or a decrease of 351–495 steps/day (pedometer alone), compared to those without one. The MCID for PA in COPD ranges from 350 steps/day to 1100 steps/day.

Sleep disturbance and next-day physical activity in COPD patients

Physical inactivity and sleep disturbance are more problematic in patients with chronic obstructive pulmonary disease (COPD) than in healthy individuals. The purpose of the study was to identify impacts of nighttime sleep on next-day physical activity in COPD patients. The study included 52 COPD patients reporting disturbed sleep. Sleep and physical activity were measured using an accelerometer for 5 days. Increased sleep latency was associated with less next-day physical activity during the afternoon (4-6 p.m.). Greater waking duration/times were associated with less next-morning (6-8 a.m.) physical activity. Greater total sleep time was associated with less next-morning (12-9 a.m.) physical activity, and greater sleep efficiency was associated with less next-morning (1-3 a.m.) and more next-evening (6-7 p.m.) physical activity. Results suggest that sleep disturbance had varying influences on next-day hourly physical activity. These results support the potential value of sleep management in promoting physical activity in COPD patients.

Advanced nursing practice in COPD exacerbations: the solution for a gap in Switzerland?

Aim

This study aimed to address the need for adaptation of the current model of chronic obstructive pulmonary disease (COPD) care in Switzerland, particularly in regard to acute exacerbations, and how far an integrated approach involving advanced nursing practice can meet those needs.

Methods

A state analysis guided by the PEPPA framework was initiated by the Pulmonology Clinic of University Hospital Zürich. Literature describing the current provision of COPD care regarding exacerbations in Switzerland and international qualitative studies describing the patient perspective were systematically searched and summarised. The health providers' perspective was investigated in three focus-group interviews.

Results

A lack of systematic and state-of-the-art support for patient self-management in Switzerland was described in literature and confirmed by the health providers interviewed. While care was assessed as being comprehensive and of good quality in each individual sector, such as inpatient, outpatient, rehabilitation and home settings, it was identified as being highly fragmented across sectors. The interview participants described day-to-day examples in which a lack of support in COPD self-management and fragmentation of care negatively affected the patients' disease management.

Conclusion

The necessity of coordinating the transition between healthcare sectors and self-management support and that these organisational boundaries should be addressed by a multi-professional team were identified. Initial evaluation indicates that advanced practice nurses potentially have the skill set to coordinate the team and address patients' self-management needs in complex patient situations. However, the legal foundation and a reimbursement system to ensure long-term implementation is not yet available.

Advanced practice nurses have the skills to meet needs in the treatment of #AECOPD, such as transition between healthcare sectors and systematic self-management support, but the legal and financial framework is not present in Switzerland yethttps://bit.ly/2wQysHV

The Use of a Smartphone App and an Activity Tracker to Promote Physical Activity in the Management of Chronic Obstructive Pulmonary Disease: Randomized Controlled Feasibility Study

Background

Chronic obstructive pulmonary disease (COPD) is highly prevalent and significantly affects the daily functioning of patients. Self-management strategies, including increasing physical activity, can help people with COPD have better health and a better quality of life. Digital mobile health (mHealth) techniques have the potential to aid the delivery of self-management interventions for COPD. We developed an mHealth intervention (Self-Management supported by Assistive, Rehabilitative, and Telehealth technologies-COPD [SMART-COPD]), delivered via a smartphone app and an activity tracker, to help people with COPD maintain (or increase) physical activity after undertaking pulmonary rehabilitation (PR).

Objective

This study aimed to determine the feasibility and acceptability of using the SMART-COPD intervention for the self-management of physical activity and to explore the feasibility of conducting a future randomized controlled trial (RCT) to investigate its effectiveness.

Methods

We conducted a randomized feasibility study. A total of 30 participants with COPD were randomly allocated to receive the SMART-COPD intervention (n=19) or control (n=11). Participants used SMART-COPD throughout PR and for 8 weeks afterward (ie, maintenance) to set physical activity goals and monitor their progress. Questionnaire-based and physical activity–based outcome measures were taken at baseline, the end of PR, and the end of maintenance. Participants, and health care professionals involved in PR delivery, were interviewed about their experiences with the technology.

Results

Overall, 47% (14/30) of participants withdrew from the study. Difficulty in using the technology was a common reason for withdrawal. Participants who completed the study had better baseline health and more prior experience with digital technology, compared with participants who withdrew. Participants who completed the study were generally positive about the technology and found it easy to use. Some participants felt their health had benefitted from using the technology and that it assisted them in achieving physical activity goals. Activity tracking and self-reporting were both found to be problematic as outcome measures of physical activity for this study. There was dissatisfaction among some control group members regarding their allocation.

Conclusions

mHealth shows promise in helping people with COPD self-manage their physical activity levels. mHealth interventions for COPD self-management may be more acceptable to people with prior experience of using digital technology and may be more beneficial if used at an earlier stage of COPD. Simplicity and usability were more important for engagement with the SMART-COPD intervention than personalization; therefore, the intervention should be simplified for future use. Future evaluation will require consideration of individual factors and their effect on mHealth efficacy and use; within-subject comparison of step count values; and an opportunity for control group participants to use the intervention if an RCT were to be carried out. Sample size calculations for a future evaluation would need to consider the high dropout rates.

Association between self-reported moderate to vigorous physical activity and the rate of outpatient treated COPD exacerbations: retrospective cohort study

Introduction

Little has been published regarding the relationship between physical activity (PA) and outpatient treated, mild to moderate acute exacerbation of chronic obstructive pulmonary disease exacerbations (AECOPD). The purpose of this study was to determine the association between self-reported PA and outpatient treated AECOPD over 2 years using real-world data obtained from existing electronic medical records (EMRs).

Methods

We included 44 896 patients with a chronic obstructive pulmonary disease diagnosis from the EMR in this retrospective cohort study. Moderate to vigorous PA was measured via patient self-report, obtained during routine clinical care; patients were classified as inactive (0 min/week), insufficiently active (1–149 min/week) or active (≥150 min/week). AECOPDs were measured using both encounter and prescription fill (antibiotics and/or oral steroids) data. We used Poisson regression models to compare the unadjusted and adjusted rates of outpatient treated AECOPD over 2 years across the PA categories.

Results

In adjusted models, the 2-year AECOPD incidence rate ratio (IRR) was not different between the inactive and insufficiently inactive groups (IRR 0.98, 95% CI 0.96 to 1.01) and only marginally meaningful lower for the active group (IRR 0.97, 95% CI 0.95 to 0.98). Sensitivity analyses of patients meeting or not meeting obstructive criteria produced similar results with generally weak or non-significant associations.

Conclusion

The lack of an association between PA and AECOPD contrasts with previous published findings of a strong relationship between moderate to vigorous PA and hospitalisations for severe AECOPD. This difference could partially be attributed to the imprecision of our measurements for both the exposure and outcome.

Does the 6-minute walk test in hospitalized COPD patients exclusively correlate with lung function parameters or should psychological factors also be taken into account?

The 6-minute walk test is generally considered a standard test for the evaluation of short-term maximal physical performance. It has not been evaluated whether psychological factors, such as anxiety or depression, affect the performance or the results of the test. The main aim of this study was to investigate whether a correlation exists between psychological factors and the data from the 6-minute walking test. The study cohort consisted of 85 (♀ = 34 and ♂ = 51) 66 ± 10 (mean ± SD) year-old patients with chronic obstructive pulmonary disease (COPD) hospitalized for disease exacerbation. Forced Expiratory Volume in the first second (FEV₁) (% predicted) as predictor for lung function, as well as anxiety and depression symptoms assessed using the Hospital Anxiety and Depression Scale (HADS) as psychological predictors were collected. Bivariate correlations and hierarchical linear regression models were used to analyse the correlations. Walking distance was on average 260m ± 107m and ranged from 64m to 480m. HADS was negatively correlated with 6-min walking distance (r = 0.441, p = .0009, r = -.523, p = 00006). Hierarchical linear regression showed that FEV₁ alone explained 33%, and together with the psychological variables anxiety and depression explained 42% of the variance of results from the 6-minute walking test. These findings demonstrated that 11% of the data correlated with the psychological variables alone (p = .011). The effect size for lung function (f² = .717) and psychological variables (f² = .352) were high, whereas the socio-demographic variables sex, age, educational level and BMI could not explain any additional variance in our cohort. In conclusion, our study indicates that psychological factors such as symptoms of depression and anxiety are associated with lower physical functional performance in the 6-minute walking test. As such, these factors should also be assessed. Future research is needed to show if treatments of anxiety and depression can improve the walking distance in COPD patients.

Easy to Perform Physical Performance Tests to Identify COPD Patients with Low Physical Activity in Clinical Practice

Background

The study investigates which physical performance or muscle function/mass tests significantly correlate with objectively measured physical activity (PA) in patients with chronic obstructive pulmonary disease (COPD) and could potentially serve to identify physically inactive COPD patients in routine clinical practice.

Methods

A cross-sectional, observational study was conducted in outpatients with moderate to very severe COPD. PA was measured during one week with the StepWatch Activity Monitor^®, an ankle-worn accelerometer, and expressed in steps per day. Physical fitness and peripheral muscle function/mass were evaluated by the 4-meter gait speed (4MGS) test, the 6-minute walk distance (6MWD), the 30-second chair stand test (30sCST), the timed up and go test (TUGT), handgrip strength, arm muscle area, calf circumference, the fat-free mass index (FFMI), and ultrasound measurement of the quadriceps muscle. Spearman’s rank correlation analysis and ROC analysis were performed.

Results

The study population (N=111, 69% men, mean age 68 years) walked a mean of 8059 steps/day. The daily step count strongly correlated with the 6MWD (rho=0.684, p<0.001) and moderately with the 4MGS (rho=0.464, p<0.001), the TUGT (rho= −0.463, p<0.001), and the 30sCST (rho=0.402, p<0.001). The correlation with the FFMI was weak (rho=0.210, p=0.027), while the other parameters did not significantly correlate with the daily step count. The 6MWD had the best discriminative power to identify patients with very low PA defined as <5000 steps/day (AUC=0.802 [95% CI: 0.720–0.884], p<0.001), followed by the TUGT, the 4MGS, and the 30sCST.

Conclusion

The 6MWD, the 4MGS, the TUGT, and the 30sCST are easy to perform in any clinical setting and may be used by clinicians in the screening of physically inactive COPD patients.

Feasibility and acceptability of active for life with COPD, an intervention to increase light physical activity in people with COPD

BACKGROUND

People with chronic obstructive pulmonary disease (COPD) are very sedentary; increasing light physical activity (LPA) may help to promote long-term maintenance of physical activity.

OBJECTIVES

We evaluated feasibility and acceptability of Active for Life with COPD, a self-efficacy-enhancing intervention designed to increase LPA.

METHODS

The 10-week intervention included walking, functional circuit training, and behavioral and educational strategies. Measures included attrition, adherence, objectively measured physical activity, and qualitative interviews.

RESULTS

Thirty-six subjects enrolled in the study; 26 completed the intervention and 19 completed the two-month follow-up. Subjects reported the intervention was enjoyable and beneficial, but disliked the activity log and buddy system. Subjects increased mean time spent standing/stepping by 36 (SD = 82) min/24 h (P > 0.05); they retained a gain of 21 (SD = 88) min/24 h at the two-month follow-up (P > 0.05).

CONCLUSIONS

The Active for Life with COPD intervention is feasible, acceptable, and may support long term maintenance of physical activity.

Long-term effects of web-based pedometer-mediated intervention on COPD exacerbations

BACKGROUND

Technology-based physical activity (PA) interventions have been shown to improve daily step counts and health-related quality of life, but their effect on long-term clinical outcomes like acute exacerbations (AEs) is unknown in persons with COPD.

METHODS

U.S. Veterans with stable COPD were randomized (1:1) to either pedometer alone (control) or pedometer plus a website with feedback, goal-setting, disease education, and a community forum (intervention) for 3 months. AEs were assessed every 3 months over a follow-up period of approximately 15 months. Pedometer-assessed daily step counts, health-related quality-of-life (HRQL), and self-efficacy were assessed at baseline, end-of-intervention at 3 months, and during follow-up approximately 6 and 12 months after enrollment. Zero-inflated Poisson models assessed the effect of the intervention on risk for AEs, compared to controls. Generalized linear mixed-effects models for repeated measures examined between-group and within-group changes in daily step count, HRQL, and self-efficacy.

RESULTS

There were no significant differences in age, FEV₁% predicted, baseline daily step count, AEs the year prior to enrollment, or duration of follow-up between the intervention (n = 57) and control (n = 52) groups. The intervention group had a significantly reduced risk of AEs (rate ratio = 0.51, [95%CI 0.31-0.85]), compared to the control group. There were no significant between-group differences in change in average daily step count, HRQL, or self-efficacy at 6 and 12 months after enrollment.

CONCLUSIONS

A 3-month internet-mediated, pedometer-based PA intervention was associated with reduced risk for AEs of COPD over 12-15 months of follow-up. ClinicalTrials.gov identifier: NCT01772082.

A new maximal bicycle test using a prediction algorithm developed from four large COPD studies

Background: Maximum exercise workload (W_MAX) is today assessed as the first part of Cardiopulmonary Exercise testing. The W_MAX test exposes patients with COPD, often having cardiovascular comorbidity, to risks. Our research project was initiated with the final aim to eliminate the W_MAX test and replace this test with a predicted value of W_MAX, based on a prediction algorithm of W_MAX derived from multicentre studies.

Methods: Baseline data (W_MAX, demography, lung function parameters) from 850 COPD patients from four multicentre studies were collected and standardized. A prediction algorithm was prepared using Random Forest modelling. Predicted values of W_MAX were used in a new W_MAX test, which used a linear increase in order to reach the predicted W_MAX within 8 min. The new W_MAX test was compared with the standard stepwise W_MAX test in a pilot study including 15 patients with mild/moderate COPD.

Results: The best prediction algorithm of W_MAX included age, sex, height, weight, and six lung function parameters. FEV₁ and DLCO were the most important predictors. The new W_MAX test had a better correlation (R² = 0.84) between predicted and measured W_MAX than the standard W_MAX test (R² = 0.66), with slopes of 0.50 and 0.46, respectively. The results from the new W_MAX test and the standard W_MAX test correlated well.

Conclusion: A prediction algorithm based on data from four large multicentre studies was used in a new W_MAX test. The prediction algorithm provided reliable values of predicted W_MAX. In comparison with the standard W_MAX test, the new W_MAX test provided similar overall results.

Telomere length in COPD: Relationships with physical activity, exercise capacity, and acute exacerbations

RATIONALE

Shorter leukocyte telomere length (LTL) is associated with reduced health-related quality of life and increased risk for acute exacerbations (AEs) and mortality in chronic obstructive pulmonary disease (COPD). Increased physical activity and exercise capacity are associated with reduced risk for AEs and death. However, the relationships between LTL and physical activity, exercise capacity, and AEs in COPD are unknown.

METHODS

Data from 3 COPD cohorts were examined: Cohort 1 (n = 112, physical activity intervention trial), Cohorts 2 and 3 (n = 182 and 294, respectively, separate observational studies). Subjects completed a 6-minute walk test (6MWT) and provided blood for LTL assessment using real-time PCR. Physical activity was measured as average daily step count using an accelerometer or pedometer. Number of self-reported AEs was available for 1) the year prior to enrollment (Cohorts 1 and 3) and 2) prospectively after enrollment (all cohorts). Multivariate models examined associations between LTL and average daily step count, 6MWT distance, and AEs.

RESULTS

A significant association between longer LTL and increased 6MWT distance was observed in the three combined cohorts (β = 3x10-5, p = 0.045). No association between LTL and average daily step count was observed. Shorter LTL was associated with an increased number of AEs in the year prior to enrollment (Cohorts 1 and 3 combined, β = -1.93, p = 0.04) and with prospective AEs (Cohort 3, β = -1.3388, p = 0.0003).

CONCLUSIONS

Among COPD patients, increased LTL is associated with higher exercise capacity, but not physical activity. Shorter LTL was associated with AEs in a subgroup of cohorts.