Measuring free-living physical activity in COPD patients: Deriving methodology standards for clinical trials through a review of research studies

Implementing sensor-based digital health technologies in clinical trials: Key considerations from the eCOA Consortium

The increased use of sensor-based digital health technologies (DHTs) in clinical trials brought to light concerns about implementation practices that might introduce burden on trial participants, resulting in suboptimal compliance and become an additional complicating factor in clinical trial conduct. These concerns may contribute to the lower-than-anticipated uptake of DHT deployment and data use for regulatory decision-making, despite well-articulated benefits. The Electronic Clinical Outcome Assessment (eCOA) Consortium gathered collective experience on deploying sensor-based DHTs and supplemented this with relevant literature focusing on mechanisms that may enhance participant compliance. The process for DHT implementation starts with identifying a clinical concept of interest followed by a digital measure selection, defining active or passive data capture and their sources, the number of sensors with respective body location, plus the duration and frequency of use in the context of perceived participant burden. Roundtable discussions among patient groups, physicians, and technology providers prior to protocol development can be very impactful for optimizing trial design. While diversity and inclusion are essential for any clinical trial, patient populations should be considered carefully in the context of trial-specific aims, requirements, and anticipated patient burden. Minimizing site burden includes assessment of training, research engagement, and logistical burden which needs to be triaged differently for early and late-stage clinical trials. Additional considerations include sharing trial results with study participants and leveraging publicly available data for compliance modeling. To the best of our knowledge, this report provides holistic considerations for sensor-based DHT implementation that may optimize participant compliance.

Unleashing the full potential of digital outcome measures in clinical trials: eight questions that need attention

The use of digital health technologies to measure outcomes in clinical trials opens new opportunities as well as methodological challenges. Digital outcome measures may provide more sensitive and higher-frequency measurements but pose vital statistical challenges around how such outcomes should be defined and validated and how trials incorporating digital outcome measures should be designed and analysed. This article presents eight methodological questions, exploring issues such as the length of measurement period, choice of summary statistic and definition and handling of missing data as well as the potential for new estimands and new analyses to leverage the time series data from digital devices. The impact of key issues highlighted by the eight questions on a primary analysis of a trial are illustrated through a simulation study based on the 2019 Bellerophon INOPulse trial which had time spent in MVPA as a digital outcome measure. These eight questions present broad areas where methodological guidance is needed to enable wider uptake of digital outcome measures in trials.

Statistical analysis of actigraphy data with generalised additive models

There is a growing interest in the use of physical activity data in clinical studies, particularly in diseases that limit mobility in patients. High-frequency data collected with digital sensors are typically summarised into actigraphy features aggregated at epoch level (e.g., by minute). The statistical analysis of such volume of data is not straightforward. The general trend is to derive metrics, capturing specific aspects of physical activity, that condense (say) a week worth of data into a single numerical value. Here we propose to analyse the entire time-series data using Generalised Additive Models (GAMs). GAMs are semi-parametric models that allow inclusion of both parametric and non-parametric terms in the linear predictor. The latter are smooth terms (e.g., splines) and, in the context of actigraphy minute-by-minute data analysis, they can be used to assess daily patterns of physical activity. This in turn can be used to better understand changes over time in longitudinal studies as well as to compare treatment groups. We illustrate the application of GAMs in two clinical studies where actigraphy data was collected: a non-drug, single-arm study in patients with amyotrophic lateral sclerosis, and a physical-activity sub-study included in a phase 2b clinical trial in patients with chronic obstructive pulmonary disease.

Changes in physical activity, sedentary behaviour and sleep following pulmonary rehabilitation: a systematic review and network meta-analysis

BACKGROUND

The variety of innovations to traditional centre-based pulmonary rehabilitation (CBPR), including different modes of delivery and adjuncts, are likely to lead to differential responses in physical activity, sedentary behaviour and sleep.

OBJECTIVES

To examine the relative effectiveness of different pulmonary rehabilitation-based interventions on physical activity, sedentary behaviour and sleep.

METHODS

Randomised trials in chronic respiratory disease involving pulmonary rehabilitation-based interventions were systematically searched for. Network meta-analyses compared interventions for changes in physical activity, sedentary behaviour and sleep in COPD.

RESULTS

46 studies were included, and analyses were performed on most common outcomes: steps per day (k=24), time spent in moderate-to-vigorous physical activity (MVPA; k=12) and sedentary time (k=8). There were insufficient data on sleep outcomes (k=3). CBPR resulted in greater steps per day and MVPA and reduced sedentary time compared to usual care. CBPR+physical activity promotion resulted in greater increases in steps per day compared to both usual care and CBPR, with greater increases in MVPA and reductions in sedentary time compared to usual care, but not CBPR. Home-based pulmonary rehabilitation resulted in greater increases in steps per day and decreases in sedentary time compared to usual care. Compared to usual care, CBPR+physical activity promotion was the only intervention where the lower 95% confidence interval for steps per day surpassed the minimal important difference. No pulmonary rehabilitation-related intervention resulted in greater increases in MVPA or reductions in sedentary time compared to CBPR.

CONCLUSION

The addition of physical activity promotion to pulmonary rehabilitation improves volume of physical activity, but not intensity, compared to CBPR. High risk of bias and low certainty of evidence suggests that these results should be viewed with caution.

Effects of ActiGraph's filter, epoch length and non-wearing time algorithm on step counts in people with COPD

The influence of the ActiGraph® processing criteria on estimating step counts in chronic obstructive pulmonary disease (COPD) remains uncertain. This study aimed to assess the influence of filters, epoch lengths and non-wearing time (NWT) algorithms on steps/day in people with COPD. ActiGraph GT3X+ was worn on the waist for seven days. Steps were detected using different filters (normal and low-frequency extension [LFE]), epoch lengths (15s and 60s), and NWT algorithms (Choi and Troiano). Linear mixed-effects model was applied to assess the effects of filter, epoch length, NWT algorithm on steps/day. Lin's concordance correlation and Bland-Altman were used to measure agreement. A total of 136 people with COPD (107 male; 69 ± 8 years; FEV1 51 ± 17% predicted) were included. Significant differences were found between filters (p < 0.001), but not between epoch lengths or NWT algorithms. The LFE increased, on average, approximately 7500 steps/day compared to the normal filter (p < 0.001). Agreement was poor (<0.3) and proportional bias was significant when comparing steps/day computed with different filters, regardless of the epoch length and NWT algorithm. Filter choice but not epoch lengths or NWT algorithms seem to impact measurement of steps/day. Future studies are needed to recommend the most accurate technique for measuring steps/day in people with COPD.

Is education level, as a proxy for socio-economic position, related to device-measured and self-reported sedentary behavior in European older adults? A cross-sectional study from the SITLESS project

Background

Sedentary behavior (SB) is a determinant of health in older adult people. Educational level is a primary driver of health disparities and is demonstrated to be a reliable measure of socioeconomic position. We aimed to examine the associations between educational level and self-reported along with device-measured SB in older adults living in Europe and the association of mentally active and passive SB domains with the educational level and gender in these associations.

Methods

The design is cross-sectional. One thousand three hundred and sixty participants aged 65 and over (75.3±6.3 years old, 61.8% women) participated. Inclusion criteria were scored with the Short Physical Performance Battery. Variables that describe the sample were assessed with an interview, and device-measured SB was assessed with an accelerometer. SB was assessed with the Sedentary Behavior Questionnaire and an accelerometer. Multiple linear regression models were used to study the association between the level of education and SB.

Results

Participants self-reported an average of 7.82 (SD: 3.02) daily waking hours of SB during weekend days, and the average of device-measured SB was 11.39 (1.23) h. Total mentally active SB (weekdays and weekends) was associated with the education level (p < 0.000). Participants were more sedentary during the week than during weekends, regardless of level of education (p < 0.000). Education level was significantly associated with self-reported mean hours per day in 46SB (p = 0.000; R=0.026; 95%CI).

Conclusion

Low education level in older adults is associated with self-reported SB but not with objective SB measures.

Clinical Characteristics of Individuals with Interstitial Lung Diseases and Indication of End-of-Life Care

End-of-life care (EOLC) is palliative support provided in the last 6 months to 1 year of a patient's life. Although there are established criteria for its indication, few studies describe the clinical and functional characteristics of individuals with interstitial lung diseases (ILD) in EOLC. ILD individuals underwent various assessments, including lung function, exercise capacity (6 min walk test), physical activity in daily life (PADL), peripheral muscle strength, maximal respiratory pressures, body composition, quality of life (SGRQ-I), symptoms of anxiety and depression, dyspnea (MRC scale), and sleep quality. Fifty-eight individuals were included and divided into two groups according to the indication for commencing EOLC (ILD with an indication of EOLC (ILD-EOLC) or ILD without an indication of EOLC (ILD-nEOLC). There were differences between the groups, respectively, for steps/day (2328 [1134-3130] vs. 5188 [3863-6514] n/day, p = 0.001), time spent/day carrying out moderate-to-vigorous physical activities (1 [0.4-1] vs. 10 [3-19] min/day, p = 0.0003), time spent/day in standing (3.8 [3.2-4.5] vs. 4.8 [4.1-6.7] h/day, p = 0.005), and lying positions (5.7 [5.3-6.9] vs. 4.2 [3.6-5.1] h/day, p = 0.0004), the sit-to-stand test (20 ± 4 vs. 26 ± 7 reps, p = 0.01), 4 m gait speed (0.92 ± 0.21 vs. 1.05 ± 0.15 m/s, p = 0.02), quadriceps muscle strength (237 [211-303] vs. 319 [261-446] N, p = 0.005), SGRQ-I (71 ± 15 vs. 50 ± 20 pts, p = 0.0009), and MRC (4 [3-5] vs. 2 [2-3] pts, p = 0.001). ILD individuals with criteria for commencing EOLC exhibit reduced PADL, functional performance, peripheral muscle strength, quality of life, and increased dyspnea.

Physical activity measurements in individuals with interstitial lung disease: a systematic review and meta-analysis

BACKGROUND

Physical activity (PA) measurements are becoming common in interstitial lung disease (ILD); however, standardisation has not been achieved. We aimed to systematically review PA measurement methods, present PA levels and provide practical recommendations on PA measurement in ILD.

METHODS

We searched four databases up to November 2022 for studies assessing PA in ILD. We collected information about the studies and participants, the methods used to measure PA, and the PA metrics. Studies were scored using 12 items regarding PA measurements to evaluate the reporting quality of activity monitor use.

RESULTS

In 40 of the included studies, PA was measured using various devices or questionnaires with numerous metrics. Of the 33 studies that utilised activity monitors, a median of five out of 12 items were not reported, with the definition of nonwear time being the most frequently omitted. The meta-analyses showed that the pooled means (95% CI) of steps, time spent in moderate to vigorous PA, total energy expenditure and sedentary time were 5215 (4640-5791) steps·day^-1, 82 (58-106) min·day^-1, 2130 (1847-2412) kcal·day^-1 and 605 (323-887) min·day^-1, respectively, with considerable heterogeneity.

CONCLUSION

The use of activity monitors and questionnaires in ILD lacks consistency. Improvement is required in the reporting quality of PA measurement methods using activity monitors.

Effect of Data Reduction Techniques on Daily Moderate to Vigorous Physical Activity Collected with ActiGraph® in People with COPD

ActiGraph® is a valid, frequently used, accelerometer to quantify moderate to vigorous physical activities (MVPA) in people with COPD. The impact of ActiGraph processing techniques on this population is unknown. This study aimed to explore the effect of data reduction techniques on MVPA in people with COPD. MVPA/day, through ActiGraph GT3X+, was estimated using: Troiano, Freedson 98 and FreedsonVM3 cutoffs, 15-s and 60-s epochs, and normal and low-frequency extension (LFE) filters. Cutoff, epoch, and filter effects were explored with Aligned Rank Transform-ANOVA. Lin's concordance correlation coefficients and Bland-Altman plots were used to evaluate agreement and bias between different techniques. The analysis included 136 people with COPD (79% male; 68 ± 8 years; FEV1 51 ± 17% predicted). MVPA/day differed according to cutoff, filter, and epoch selection (p-value < 0.001). FreedsonVM3 cutoff, 15-s epochs, and LFE yielded the highest MVPA (45 min/day, 68% of physically active participants). Troiano cutoff, 60-s epochs, and normal filter yielded the lowest MVPA (8 min/day, 20% of physically active participants). Only comparisons between Troiano and Freedson98 cutoffs presented an almost perfect agreement. ActiGraph data reduction techniques affected MVPA/day estimates and their interpretation at the individual and group level. Studies using different processing criteria should not be compared in people with COPD. Future studies with a gold standard are required to ascertain which processing technique produces the most accurate MVPA estimates in COPD. Meanwhile, future trials employing the ActiGraph GT3X+ may consider estimating MVPA based on Freedson VM3 cutofffs, 60-s epochs, and normal filter.

Deriving Meaningful Aspects of Health Related to Physical Activity in Chronic Disease: Concept Elicitation Using Machine Learning-Assisted Coding of Online Patient Conversations

OBJECTIVES

Clinical outcome assessment (COA) developers must ensure that measures assess aspects of health that are meaningful to the target patient population. Although the methodology for doing this is well understood for certain COAs, such as patient-reported outcome measures, there are fewer examples of this practice in the development of digital endpoints using mobile sensor technology such as physical activity monitors. This study explored the utility of social media data, specifically, posts on online health boards, in understanding meaningful aspects of health related to physical activity in 3 different chronic diseases: fibromyalgia, chronic obstructive pulmonary disease, and chronic heart failure.

METHODS

We used machine learning and manual coding to summarize the content of posts extracted from 4 online health boards. Where available, patient age and sex were retrieved from post content or user profiles. We utilized analytical approaches to assess the robustness of findings to differences in the characteristics of online samples compared to the true patient population. Finally, we assessed concept saturation by measuring the convergence of autocorrelations.

RESULTS

We identify a number of aspects of health described as important by patients in our samples, and summarize these into concepts for measurement. For chronic heart failure, these included purposeful walking duration and speed, fatigue, difficulty going upstairs, standing, and aspects of physical exercise. Overall and age-adjusted results did not differ considerably for each disease group.

CONCLUSIONS

This study illustrates the potential of performing concept elicitation research using social media data, which may provide valuable insight to inform COA development.

From Meaningful Outcomes to Meaningful Change Thresholds: A Path to Progress for Establishing Digital Endpoints

This paper examines the use of digital endpoints (DEs) derived from digital health technologies (DHTs), focusing primarily on the specific considerations regarding the determination of meaningful change thresholds (MCT). Using DHTs in drug development is becoming more commonplace. There is general acceptance of the value of DHTs supporting patient-centric trial design, capturing data outside the traditional clinical trial setting, and generating DEs with the potential to be more sensitive to change than conventional assessments. However, the transition from exploratory endpoints to primary and secondary endpoints capable of supporting labeling claims requires these endpoints to be substantive with reproducible population-specific values. Meaningful change represents the amount of change in an endpoint measure perceived as important to patients and should be determined for each digital endpoint and given population under consideration. This paper examines existing approaches to determine meaningful change thresholds and explores examples of these methodologies and their use as part of DE development: emphasizing the importance of determining what aspects of health are important to patients and ensuring the DE captures these concepts of interest and aligns with the overarching endpoint strategy. Examples are drawn from published DE qualification documentation and responses to qualification submissions under review by the various regulatory authorities. It is the hope that these insights will inform and strengthen the development and validation of DEs as drug development tools, particularly for those new to the approaches to determine MCTs.

Physical Activity, Exercise Capacity and Sedentary Behavior in People with Alpha-1 Antitrypsin Deficiency: A Scoping Review

Alpha-1 antitrypsin deficiency (AATD) is a hereditary disorder and a genetic risk factor for chronic obstructive pulmonary disease (COPD). Physical activity (PA) is important for the prevention and treatment of chronic disease. Little is known about PA in people with AATD. Therefore, we aimed to map the research undertaken to improve and/or measure PA, sedentary behaviour (SB) or exercise in people with AATD. Searches were conducted in CINAHL, Medline, EMBASE and clinical trial databases for studies published in 2021. Databases were searched for keywords (physical activity, AATD, exercise, sedentary behavior) as well as synonyms of these terms, which were connected using Boolean operators. The search yielded 360 records; 37 records were included for review. All included studies (n = 37) assessed exercise capacity; 22 studies reported the use of the six-minute walk test, the incremental shuttle walk test and cardiopulmonary exercise testing were reported in three studies each. Other objective measures of exercise capacity included a submaximal treadmill test, the Naughton protocol treadmill test, cycle ergometer maximal test, endurance shuttle walk test, constant cycle work rate test, a peak work rate test and the number of flights of stairs a participant was able to walk without stopping. A number of participant self-reported measures of exercise capacity were noted. Only one study aimed to analyze the effects of an intensive fitness intervention on daily PA. One further study reported on an exercise intervention and objectively measured PA at baseline. No studies measured SB. The assessment of PA and use of PA as an intervention in AATD is limited, and research into SB absent. Future research should measure PA and SB levels in people with AATD and explore interventions to enhance PA in this susceptible population.

Pulmonary Telerehabilitation for People With Chronic Obstructive Pulmonary Disease in Brazil: A Mixed-Methods Feasibility Study

This study assessed the feasibility of pulmonary telerehabilitation‧s (PTR) acceptability, implementation, practicality, and adaptation for people with Chronic Obstructive Pulmonary Disease (COPD) in Brazil. It also explored associations with clinical and socioeconomic features of Brazilians with COPD. This mixed-method study included thirty-one participants with COPD (age 62±10 years; FEV1= 72±14% predicted). Most participants (74.2%) reported good PTR session acceptability on the System Usability Scale and scores of 4.6±0.3 and 4.5±0.6 on a 1-5 Likert-type scale of implementation and practicality, respectively. Participants suggested adaptations for better comfort on the exercise bike and varying exercise modalities. PTR acceptability was associated with participants' younger age (rs=-0.57, p<0.01) and higher education (rs=0.51, p<0.01). PTR is feasible for people with COPD in Brazil regarding acceptability, implementation, practicality, and adaptation. Younger age and higher educational level are associated with greater PTR acceptability.

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.

Validity and Accuracy of Step Count as an Indicator of a Sedentary Lifestyle in People With Chronic Obstructive Pulmonary Disease

OBJECTIVE

To determine the validity and accuracy of <5000 steps/day as a sedentary lifestyle indicator, and the optimal step count cut point value for indicating a sedentary lifestyle in people with chronic obstructive pulmonary disease (COPD).

DESIGN

Analysis of baseline data from a randomized clinical trial.

SETTING

Sydney, Australia.

PARTICIPANTS

Stable COPD on the waitlist for pulmonary rehabilitation.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Step count and time in sedentary behavior (SB) were assessed using thigh-worn accelerometry. A sedentary lifestyle was defined as <5000 steps/day. Pearson correlation coefficients were analyzed between step count and time spent in SB. Sensitivity, specificity, and accuracy were calculated for the <5000 steps/day threshold. Receiver operating characteristic curves with the area under the curve were computed for step count in identifying a sedentary lifestyle.

RESULTS

69 people with COPD (mean age=74 years, SD=9; forced expiratory volume in 1 second, mean=55%, SD=19 predicted) had sufficient wear data for analysis. There was a moderate inverse correlation between step count and time spent in SB (r=-0.58, P<.001). Step count had a fair discriminative ability for identifying a sedentary lifestyle (area under the curve=0.80, 95% confidence interval [CI], 0.68-0.91). The <5000 steps/day threshold had a sensitivity, specificity, and accuracy of 82% (95% CI, 70-94), 70% (95% CI, 54-86), and 78%, respectively. A lower threshold of <4300 steps/day was more accurate for ruling in a sedentary lifestyle.

CONCLUSIONS

Compared with thigh-worn accelerometry, <5000 steps/day is a valid and reasonably accurate indicator of a sedentary lifestyle in this population.

Device assessed activity behaviours in patients with indwelling pleural catheter: A sub-study of the Australasian Malignant PLeural Effusion (AMPLE)-2 randomized trial

BACKGROUND AND OBJECTIVE

Device-assessed activity behaviours are a novel measure for comparing intervention outcomes in patients with malignant pleural effusion (MPE). Australasian Malignant PLeural Effusion (AMPLE)-2 was a multi-centre clinical trial where participants with MPE treated with an indwelling pleural catheter were randomized to daily (DD) or symptom-guided (SGD) drainage for 60-days. Our aim was to describe activity behaviour patterns in MPE patients, explore the impact of drainage regimen on activity behaviours and examine associations between activity behaviours and quality of life (QoL).

METHODS

Following randomization to DD or SGD, participants enrolled at the lead site (Perth) completed accelerometry assessment. This was repeated monthly for 5-months. Activity behaviour outcomes were calculated as percent of daily waking-wear time and compared between groups (Mann-Whitney U test; Median [IQR]). Correlations between activity behaviour outcomes and QoL were examined.

RESULTS

Forty-one (91%) participants provided ≥1 valid accelerometry assessment (DDn = 20, SGD n = 21). Participants spent a large proportion of waking hours sedentary (72%-74% across timepoints), and very little time in moderate-to-vigorous physical activity (<1% across timepoints). Compared to SGD group, DD group had a more favourable sedentary-to-light ratio in the week following randomization (2.4 [2.0-3.4] vs. 3.2 [2.4-6.1]; p = 0.047) and at 60-days (2.0 [1.9-2.9] vs. 2.9 [2.8-6.0]; p = 0.016). Sedentary-to-light ratio was correlated with multiple QoL domains at multiple timepoints.

CONCLUSION

Patients with MPE are largely sedentary. Preliminary results suggest that even modest differences in activity behaviours favouring the DD group could be meaningful for this clinical population. Accelerometry reflects QoL and is a useful outcome measure in MPE populations.

A Call for Action on Chronic Respiratory Diseases within Physical Activity Policies, Guidelines and Action Plans: Let's Move!

Global policy documents for the promotion of physical activity (PA) play an important role in the measurement, evaluation, and monitoring of population PA levels. The World Health Organisation (WHO) guidelines include, for the first time, recommendations for specific populations, including individuals living with a range of non-communicable diseases. Of note, is the absence of any chronic respiratory diseases (CRDs) within the recommendations. Globally, CRDs are highly prevalent, are attributable to significant individual and societal burdens, and are characterised by low PA. As a community, there is a need to come together to understand how to increase CRD representation within global PA policy documents, including where the evidence gaps are and how we can align with PA research in other contexts. In this commentary, the potential for synergy between evidence into the relationships between PA in CRDs globally and the relevance to current policies, guidelines and action plans on population levels of PA are discussed. Furthermore, actions and considerations for future research, including the need to harmonize and promote PA assessment (particularly in low- and middle-income countries) and encompass the synergistic influences of PA, sedentary behaviour and sleep on health outcomes in CRD populations are presented.

Deriving personalised physical activity intensity thresholds by merging accelerometry with field-based walking tests: Implications for pulmonary rehabilitation

During pulmonary rehabilitation (PR), patients receive individually tailored walking exercise training. The personalised nature of exercise prescription is a fundamental component of PR. Despite this, the measurement of physical activity (PA) has been limited to a 'one size fits all' approach and can be challenging to translate into clinically meaningful or real-world units, such as cadence. This discrepancy may partly explain the inconsistent evidence for the impact of PR on PA. It may also provide an opportunity to standardise PA assessment in the context of chronic respiratory disease (CRD) and PR, where field-based walking tests are routine measures. This technical note provides an example of how to develop personalised PA intensity thresholds, calibrated against an individual's performance on the Incremental Shuttle Walking Test (ISWT; maximal) and Endurance Shuttle Walk Test (ESWT; sub-maximal). These are externally paced tests, with each level (speed) of the tests denoting a specific speed (intensity); ranging 1.8 km/h (ISWT Level 1) to 8.5 km/h (ISWT Level 12). From the ESWT, it becomes possible to evaluate adherence to each individual's walking exercise prescription. Future research should explore this approach and its responsiveness to PR. It may be possible to extend this methodology with the inclusion of physiological parameters (e.g., heart rate, calorimetry, and oxygen consumption) to derive relative intensity markers (e.g. moderate-to-vigorous), accounting for individual differences in exercise capacity, under the same paradigm as PR exercise prescription.

A More Intense Examination of the Intensity of Physical Activity in People Living with Chronic Obstructive Pulmonary Disease: Insights from Threshold-Free Markers of Activity Intensity

Physical activity (PA) intensity of people living with chronic obstructive pulmonary disease (COPD) is typically evaluated using intensity thresholds developed in younger, healthier populations with greater exercise capacity and free from respiratory symptoms. This study therefore compared (i) PA differences between COPD and non-COPD controls using both traditional intensity thresholds and threshold-free metrics that represent the volume and intensity of the whole PA profile, and (ii) explored the influence of exercise capacity on observed differences. Moderate-to-vigorous physical activity (MVPA), average acceleration (proxy for volume, mg) and intensity distribution of activity were calculated for 76 individuals with COPD and 154 non-COPD controls from wrist-worn ActiGraph accelerometry. PA profiles representing the minimum intensity (acceleration, mg) during the most active accumulated 5-960 min were plotted. Estimated VO_2peak and relative intensity were derived from the incremental shuttle walk test distance. Compared to the non-COPD control group, individuals with COPD recorded fewer MVPA minutes (59 vs. 83 min/day), lower overall waking activity (29.1 vs. 36.4 mg) and a poorer waking intensity distribution (-2.73 vs. -2.57). Individuals with COPD also recorded a lower absolute intensity (acceleration, mg) for their most active 5-960 min, but higher intensity relative to their estimated exercise capacity derived from the ISWT. People with COPD have a lower volume and absolute intensity of PA than controls but perform PA at a higher relative intensity. There is a need to move away from absolute intensity thresholds, and towards personalised or relative-intensity thresholds, to reflect reduced exercise capacity in COPD populations.

Considerations for Conducting Bring Your Own “Device” (BYOD) Clinical Studies

Background

Digital health technologies are attracting attention as novel tools for data collection in clinical research. They present alternative methods compared to in-clinic data collection, which often yields snapshots of the participants' physiology, behavior, and function that may be prone to biases and artifacts, e.g., white coat hypertension, and not representative of the data in free-living conditions. Modern digital health technologies equipped with multi-modal sensors combine different data streams to derive comprehensive endpoints that are important to study participants and are clinically meaningful. Used for data collection in clinical trials, they can be deployed as provisioned products where technology is given at study start or in a bring your own “device” (BYOD) manner where participants use their technologies to generate study data.

Summary

The BYOD option has the potential to be more user-friendly, allowing participants to use technologies that they are familiar with, ensuring better participant compliance, and potentially reducing the bias that comes with introducing new technologies. However, this approach presents different technical, operational, regulatory, and ethical challenges to study teams. For example, BYOD data can be more heterogeneous, and recruiting historically underrepresented populations with limited access to technology and the internet can be challenging. Despite the rapid increase in digital health technologies for clinical and healthcare research, BYOD use in clinical trials is limited, and regulatory guidance is still evolving.

Key Messages

We offer considerations for academic researchers, drug developers, and patient advocacy organizations on the design and deployment of BYOD models in clinical research. These considerations address: (1) early identification and engagement with internal and external stakeholders; (2) study design including informed consent and recruitment strategies; (3) outcome, endpoint, and technology selection; (4) data management including compliance and data monitoring; (5) statistical considerations to meet regulatory requirements. We believe that this article acts as a primer, providing insights into study design and operational requirements to ensure the successful implementation of BYOD clinical studies.

Impact of non-exercise activity thermogenesis on physical activity in patients with COPD

Physical inactivity is associated with comorbidities and mortality in chronic obstructive pulmonary disease (COPD) patients. Although non-exercise activity thermogenesis (NEAT) is important for evaluating the physical activity level (PAL) of patients with chronic diseases, it has not yet been assessed in COPD patients. This study included male patients with COPD (n = 28) and high risk for COPD (n = 8). Total energy expenditure (TEE) and basal metabolic rate (BMR) were measured using the doubly labeled water (DLW) method and indirect calorimetry, respectively. PAL was calculated as TEE/BMR, while the NEAT was obtained from a questionnaire. Physical activity was also assessed using an accelerometer. The total NEAT score was correlated with PAL (r = 0.534, P < 0.001), while PAL was correlated more strongly with the non-locomotive NEAT score (r = 0.548, P < 0.001) than the locomotive NEAT score (r = 0.278, P = 0.10). Regarding accelerometer-obtained data, this questionnaire mainly reflected steps/day and the duration of light locomotive and non-locomotive daily activities. The NEAT score is a possible option for evaluating PAL in daily clinical practice. The present results indicated that non-locomotive activity may have a greater impact on PAL than locomotive activity in COPD patients.

Systematic Review of Physical Activity, Sedentary Behaviour and Sleep Among Adults Living with Chronic Respiratory Disease in Low- and Middle-Income Countries

Abstract

Physical activity (PA), sedentary behaviour (SB) and sleep are important lifestyle behaviours associated with chronic respiratory disease (CRD) morbidity and mortality. These behaviours need to be understood in low- and middle-income countries (LMIC) to develop appropriate interventions.

Purpose

Where and how have free-living PA, SB and sleep data been collected for adults living with CRD in LMIC? What are the free-living PA, SB and sleep levels of adults living with CRD?

Patients and Methods

The literature on free-living PA, SB and sleep of people living with CRD in LMIC was systematically reviewed in five relevant scientific databases. The review included empirical studies conducted in LMIC, reported in any language. Reviewers screened the articles and extracted data on prevalence, levels and measurement approach of PA, SB and sleep using a standardised form. Quality of reporting was assessed using bespoke criteria.

Results

Of 89 articles, most were conducted in Brazil (n=43). PA was the commonest behaviour measured (n=66). Questionnaires (n=52) were more commonly used to measure physical behaviours than device-based (n=37) methods. International Physical Activity Questionnaire was the commonest for measuring PA/SB (n=11). For sleep, most studies used Pittsburgh Sleep Quality Index (n=18). The most common ways of reporting were steps per day (n=21), energy expenditure (n=21), sedentary time (n=16), standing time (n=13), sitting time (n=11), lying time (n=10) and overall sleep quality (n=32). Studies revealed low PA levels [steps per day (range 2669-7490steps/day)], sedentary lifestyles [sitting time (range 283-418min/day); standing time (range 139-270min/day); lying time (range 76-119min/day)] and poor sleep quality (range 33-100%) among adults with CRD in LMIC.

Conclusion

Data support low PA levels, sedentary lifestyles and poor sleep among people in LMIC living with CRDs. More studies are needed in more diverse populations and would benefit from a harmonised approach to data collection for international comparisons.

Quantifying the Effect of Monitor Wear Time and Monitor Type on the Estimate of Sedentary Time in People with COPD: Systematic Review and Meta-Analysis

In studies that have reported device-based measures of sedentary time (ST) in people with chronic obstructive pulmonary disease (COPD), we explored if the monitor type and monitor wear time moderated the estimate of this measure. Five electronic databases were searched in January 2021. Studies were included if >70% of participants had stable COPD, and measures of ST (min/day) were collected using wearable technology. Meta-regression was used to examine the influence of moderators on ST, monitor type, and wear time. The studies identified were a total of 1153, and 36 had usable data for meta-analyses. The overall pooled estimate of ST (mean [95% CI]) was 524 min/day [482 to 566] with moderate heterogeneity among effect sizes (I2 = 42%). Monitor wear time, as well as the interaction of monitor wear time and monitor type, were moderators of ST (p < 0.001). The largest difference (−318 min; 95% CI [−212 to −424]) was seen between studies where participants wore a device without a thigh inclinometer for 24 h (and removed sleep during analysis) (675 min, 95% CI [589 to 752]) and studies where participants wore a device with a thigh inclinometer for 12 h only (356 min; 95% CI [284 to 430]). In people with COPD, the monitor wear time and the interaction of the monitor wear time and the monitor type moderated the estimate of ST.

Post-operative, inpatient rehabilitation after lung transplant evaluation (PIRATE): A feasibility randomized controlled trial

BACKGROUND

Postoperative rehabilitation is crucial following lung transplantation (LTx); however, it is unclear whether intensive rehabilitation is feasible to deliver in the acute setting. We aimed to establish the feasibility and safety of intensive acute physiotherapy post-LTx.

METHODS

This feasibility trial randomized 40 adults following bilateral sequential LTx to either standard (once-daily) or intensive (twice-daily) physiotherapy. Primary outcomes were feasibility (recruitment and delivery of intensive intervention) and safety. Secondary outcomes included six-minute walk test; 60-second sit-to-stand; grip strength; physical activity; pain; EQ-5D-5L; length of stay; and readmissions. Data were collected at baseline, week 3, and week 10 post-LTx. ClinicalTrials.gov #NCT03095859.

RESULTS

Of 83 LTx completed during the trial, 49% were eligible and 48% provided consent. Median age was 61 years {range 18-70}; waitlist time 85 days [IQR 35-187]. Median time to first mobilization was 2 days [2-3]. Both groups received a median of 10 [7-14] standard interventions post-randomization. A median of 9 [6-18] individual intensive interventions were attempted (86% successful), the most common barrier being medical procedures/investigations (67%). No intervention-related adverse events or between-group differences in secondary outcomes were observed.

CONCLUSIONS

Acute, intensive physiotherapy was feasible and safe post-LTx. This trial provides data to underpin definitive trials to establish efficacy.

The untapped potential of physical activity monitoring for quality assurance of field-based walking tests in clinical respiratory trials

Field-based walking tests are well-established outcome measures in clinical research trials and in the evaluation of routine clinical services, including pulmonary rehabilitation. Despite widespread use, there has been little attention to, or reporting of, the quality assurance of these tests. Physical activity monitoring has become increasingly popular and data from activity monitors could be used for quality assurance of field-based walking tests. We provide examples in this article of data-driven insights possible with this approach, using data from waist-worn accelerometry, for the incremental shuttle walking test (ISWT), endurance shuttle walk test (ESWT) and six-minute walk test (6MWT). Given the multitude of devices to measure physical activity and the range metrics to describe physical activity, we also comment on some of the technical considerations to using activity monitors for walking test quality assurance. Data-driven approaches to quality assurance are already commonplace for other outcome measures in clinical respiratory trials, but little is known about this approach for field-based walking tests. The application of physical activity monitoring may be extended to other field-based exercise tests and additional rehabilitation services. This may be more challenging for self-paced walking tests such as the 6MWT. Future work should apply this approach to research trials and service evaluations to explore the impact of field-based walking test quality on performance (e.g. distance on the ISWT or time achieved for the ESWT), responsiveness to interventions (e.g. pulmonary rehabilitation) and effectiveness of training procedures (e.g. remote training for multi-site trials).

Exercise Training and Cognitive Function in Kidney Disease: Protocol for a Pilot Randomized Controlled Trial

BACKGROUND

Chronic kidney disease (CKD) is extremely common in older adults and is associated with cognitive impairment. It is hypothesized that accelerated cognitive decline in CKD results from a vascular dysfunction-induced reduction in the integrity of the brain white matter.

OBJECTIVE

The aim of this study was to describe the protocol for a study to evaluate whether exercise training provides a cerebroprotective effect by improving cerebrovascular health.

METHODS

This is a randomized controlled trial investigating feasibility and effect size.

RESULTS

Participants will be randomized to either a 24-week, home-based, walking program or a usual care group. Participants will undergo evaluation of cognitive function, brain structure via magnetic reasoning imaging, physical function, physical activity, and vascular function. The primary outcome is change in cognitive function.

DISCUSSION

The findings of this study will help determine whether exercise training influences cognitive function during a therapeutic window in the disease process of cognitive impairment in older adults with CKD.

CONCLUSION

This protocol describes a study to evaluate cognition and brain structure following a home-based exercise program to an at-risk population.

Considerations to address missing data when deriving clinical trial endpoints from digital health technologies

Digital health technologies (DHTs) enable us to measure human physiology and behavior remotely, objectively and continuously. With the accelerated adoption of DHTs in clinical trials, there is an unmet need to identify statistical approaches to address missing data to ensure that the derived endpoints are valid, accurate, and reliable. It is not obvious how commonly used statistical methods to handle missing data in clinical trials can be directly applied to the complex data collected by DHTs. Meanwhile, current approaches used to address missing data from DHTs are of limited sophistication and focus on the exclusion of data where the quantity of missing data exceeds a given threshold. High-frequency time series data collected by DHTs are often summarized to derive epoch-level data, which are then processed to compute daily summary measures. In this article, we discuss characteristics of missing data collected by DHT, review emerging statistical approaches for addressing missingness in epoch-level data including within-patient imputations across common time periods, functional data analysis, and deep learning methods, as well as imputation approaches and robust modeling appropriate for handling missing data in daily summary measures. We discuss strategies for minimizing missing data by optimizing DHT deployment and by including the patients' perspective in the study design. We believe that these approaches provide more insight into preventing missing data when deriving digital endpoints. We hope this article can serve as a starting point for further discussion among clinical trial stakeholders.

Measuring intensity during free-living physical activities in people with chronic obstructive pulmonary disease: a systematic literature review

BACKGROUND

Measuring intensity of physical activity (PA) is important to ensure safety and the effectiveness of PA interventions in chronic obstructive pulmonary disease (COPD).

OBJECTIVE

This systematic review identified which outcomes, outcome measures and instruments have been used to assess single free-living PA-related intensity in people with COPD and compared the intensity level (light, moderate, vigorous) obtained by different outcome measures.

METHODS

PubMed, Scopus, Web of Science, Cochrane Library and EBSCO were searched for original studies of COPD and assessing single free-living PA-related intensity were included. Agreement was calculated as the number of agreements between 2 measures [same intensity level]/ number of comparisons using both measures*100.

RESULTS

We included 43 studies (1282 people with COPD, mean age 66 years, 65% men, 49% FEV_1%pred) and identified 13 outcomes, 46 outcome measures and 22 instruments. The most-reported outcomes, outcome measures and instruments were dyspnoea with the Borg scale 0-10; cardiac function, via heart rate (HR) using HR monitors; and pulmonary gas exchange, namely oxygen consumption (VO₂), using portable gas analysers, respectively. The most frequently assessed PAs were walking and lifting, changing or moving weights/objects. Agreement between the outcome measures ranged from 0 (%VO_2peak vs metabolic equivalent of task [MET]; %HR_peak vs Fatigue Borg; MET vs walking speed) to 100% (%HR_reserve vs dyspnoea Borg; fatigue and exertion Borg vs walking speed). %VO_{2peak/reserve} elicited the highest intensity. Hence, Borg scores, %HR_reserve and MET may underestimate PA-related intensity.

CONCLUSIONS

Various methodologies are used to assess single free-living PA-related intensity and yield different intensity levels for the same PA. Future studies, further exploring the agreement between the different outcome measures of PA-related intensity and discussing their advantages, disadvantages and applicability in real-world settings, are urgent. These would guide future worldwide recommendations on how to assess single free-living PA-related intensity in COPD, which is essential to optimise PA interventions and ensure patient safety.

The Influence of Sedentary Behavior on the Relationship Between Cognitive Function and Vascular Function in Older Adults with and without Chronic Kidney Disease

Cognitive impairment and vascular dysfunction are common in older adults with and without chronic kidney disease (CKD). Older adults with and without CKD are also sedentary - a behavior associated with cognitive and vascular function. The objective of this study was to explore whether sedentary behavior influenced the relationship between cognitive and vascular function in older adults with preclinical cognitive impairment with and without CKD. In our study, 48 older adults underwent assessment of cognition, vascular compliance, and sedentary behavior, and relationships were explored with regression moderation analysis. Sedentary time and breaks did not moderate the relationship between vascular and cognitive function. Although significant moderation was not found, cognition, vascular function, and sedentary behavior are important to assess when evaluating older adults with and without CKD.

The "can do, do do" concept in individuals with chronic obstructive pulmonary disease: an exploration of psychological mechanisms

Background

The “can do, do do” concept aims at identifying subgroups among persons with chronic obstructive pulmonary disease (COPD). Following a two-dimensional categorization, individuals are binarily classified with respect to their levels of physical capacity (“can’t do” or “can do”) and physical activity (“don’t do” or “do do”), resulting in four disjunct quadrants. The approach has been debated recently and the latest articles have concluded that the quadrants should be specifically examined in terms of psychological aspects of physical activity. Therefore, the goal of the present study was to explore the role of psychological variables in physical activity in the context of the “can do, do do” quadrant concept.

Methods

Within the scope of secondary data analyses of the “Stay Active After Rehabilitation” (STAR) randomized controlled trial, a total of 298 COPD rehabilitants of an inpatient pulmonary rehabilitation program were grouped into the suggested quadrants. We set fixed cut-offs at 70% of relative 6-min walking test performances for healthy individuals (physical capacity dimension) and 5.000 steps per day (physical activity dimension). Univariate and multivariate logistic regression analyses served to analyze whether depression scores, fear avoidance behaviors, disease-specific anxiety, self-concordance for physical activity, and five indicators of physical activity-related health competence (PAHCO) effectively discriminated between the “don’t do” and “do do” groups.

Results

Among persons with lower relative physical capacity, depression scores, fear avoidance behaviors, and disease-specific anxiety (univariate case) significantly differentiated between the more and the less active. Among persons with higher relative physical capacity, fear avoidance behaviors, disease-specific anxiety, as well as three PAHCO indicators (physical activity-specific self-efficacy, self-control, and affect regulation) significantly separated the more and the less active. In multivariate analyses, only fear avoidance behaviors and affect regulation discriminated among individuals with better relative physical capacity.

Conclusion

The findings identified important psychological and competence-oriented variables that explain discrepancies in the quadrant concept. Based on this, we discuss implications for physical activity promotion in individuals with COPD. Respiratory research can benefit from future studies complementing the quadrant concept through further behavioral analyses.

Trial registration Clinicaltrials.gov, ID: NCT02966561. Registered 17 November, 2016, https://clinicaltrials.gov/ct2/show/NCT02966561.

Comparative assessment of ActiGraph data processing techniques for measuring sedentary behavior in adults with COPD

Objective.The ActiGraph is commonly used for measuring sedentary behavior (SB), but the best data processing technique is not established for sedentary adults with chronic illness. The purpose of this study was to process ActiGraph vertical axis and vector magnitude data with multiple combinations of filters, non-wear algorithm lengths, and cut-points and to compare ActiGraph estimates to activPAL-measured sedentary time in sedentary adults with chronic obstructive pulmonary disease (COPD).Approach.This study was a secondary analysis of adults ≥50 years (N = 59; mean age: 69.4 years;N = 31 males) with COPD. Participants woreActiGraph GT9XandactivPAL3for 7 d. ActiGraph vertical axis and vector magnitude data were processed using combinations of filters (normal, low frequency extension (LFE)), non-wear algorithm lengths (60, 90, 120 min), and cut-points for SB previously validated in older adults (two for vertical axis and three for vector magnitude data). The Bland-Altman method was used to assess concordance between sedentary time measured with 30 ActiGraph techniques and activPAL-measured sedentary time.Main results. Agreement between the two devices was moderate to strong for all techniques; concordance correlations ranged from 0.614 to 0.838. Limits of agreement were wide. The best overall technique was vector magnitude data with LFE filter, 120 min non-wear algorithm, and <40 counts/15 s SB cut-point (concordance correlation 0.838; mean difference -11.7 min d^-1).Significance. This analysis supports the use of ActiGraph vector magnitude data and LFE filter in adults with COPD, but also demonstrates that other techniques may be acceptable with appropriate cut-points. These results can guide ActiGraph data processing decisions.

Six-week behaviour change intervention to reduce sedentary behaviour in people with chronic obstructive pulmonary disease: a randomised controlled trial

INTRODUCTION

This study aimed to determine whether a 6-week behaviour change intervention was more effective than a sham intervention for reducing sedentary behaviour (SB) in people with chronic obstructive pulmonary disease (COPD).

METHODS

People with stable COPD on the waitlist for entry into pulmonary rehabilitation were recruited to this multicentre trial with randomisation (independent, concealed allocation) to either an intervention group or sham group, assessor blinding and intention-to-treat (ITT) analysis. The behaviour change intervention consisted of once weekly sessions for 6 weeks with a physiotherapist to reduce SB through education, guided goals setting and real-time feedback on SB. The sham intervention consisted of once weekly phone calls for 6 weeks to monitor health status. SB was measured continuously over 7 days using thigh-worn accelerometry (activPAL3 micro). The primary outcome was time spent in SB. Participants with at least 4 days of ≥10 hours waking wear time were included in the ITT analysis and those who reported achieving ≥70% of goals to reduce SB or who completed all sham calls were included in a per-protocol analysis.

RESULTS

70 participants were recruited and 65 completed the study (mean±SD age 74±9 years, mean FEV₁ 55%±19% predicted, 49% male). At 6 weeks, no between-group differences in time spent in SB were observed in the ITT analysis (mean difference 5 min/day, 95% CI -38 to 48) or per-protocol analysis (-16 min/day, 95% CI -80 to 48).

DISCUSSION

A 6-week behaviour change intervention did not reduce time in SB compared with a sham intervention in people with stable moderate-to-severe COPD prior to pulmonary rehabilitation.

Objectively measured physical activity as a COPD clinical trial outcome

BACKGROUND

Reduced physical activity is common in COPD and is associated with poor outcomes. Physical activity is therefore a worthy target for intervention in clinical trials, however, trials evaluating physical activity have used heterogeneous methodologies.

RESEARCH QUESTION

What is the available evidence on the efficacy and/or effectiveness of various interventions to enhance objectively measured physical activity in patients with COPD, taking into account minimal preferred methodological quality of physical activity assessment?

STUDY DESIGN AND METHODS

In this narrative review, the COPD Biomarker Qualification Consortium (CBQC) task force searched three scientific databases for articles that reported the effect of an intervention on objectively-measured physical activity in COPD. Based on scientific literature and expert consensus, only studies with ≥7 measurement days and ≥4 valid days of ≥8 hours of monitoring were included in the primary analysis.

RESULTS

37 of 110 (34%) identified studies fulfilled the criteria, investigating the efficacy and/or effectiveness of physical activity behavior change programs (n=7), mobile health or eHealth interventions (n=9), rehabilitative exercise (n=9), bronchodilation (n=6), lung volume reduction procedures (n=3) and other interventions (n=3). Results are generally variable, reflecting the large variation in study characteristics and outcomes. Few studies show an increase beyond the proposed minimal important change of 600-1100 daily steps, indicating that enhancing physical activity levels is a challenge.

INTERPRETATION

Only a third of clinical trials measuring objective physical activity in people with COPD fulfilled the pre-set criteria regarding physical activity assessment. Studies showed variable effects on physical activity even when investigating similar interventions.

Sedentary Behavior in Older Adults With Preclinical Cognitive Impairment With and Without Chronic Kidney Disease

Older adults with preclinical cognitive impairment can have chronic conditions and lifestyle factors that influence health. Sedentary behavior is common in older adults with and without chronic kidney disease (CKD). The objective of the current study was to determine the differences in sedentary behavior for older adults with preclinical cognitive impairment with and without CKD. Our study evaluated 48 older adults with preclinical cognitive impairment with and without CKD who underwent assessment of sedentary behavior via accelerometry. We found that older adults with preclinical cognitive impairment with and without CKD were sedentary, but there were no significant differences between groups. Fragmentation index was different (p < 0.05), with a lower fragmentation index found in those with CKD. Sedentary behavior should be assessed and evaluated as a potential target for interventions to improve health in these at-risk older adults; however, further investigation is needed. [Journal of Gerontological Nursing, 47(6), 35-42.].

ActiGraph and Short-term Heart Rate Variability Study Protocol: Amended for the COVID-19 Pandemic

BACKGROUND

ActiGraph accelerometry is widely used in nursing research to estimate daily physical activity. Heart rate variability (HRV), a measure of autonomic modulation, can be assessed in conjunction with the ActiGraph using a Polar H7 Bluetooth heart rate monitor. There is a paucity of nursing literature to guide nurse researchers' protocol development when using the ActiGraph to assess both physical activity and short-term HRV via its Bluetooth capabilities.

OBJECTIVES

The aim of this study was to describe a standardized research ActiGraph and HRV (ActiGraph HRV) protocol for an ongoing randomized controlled trial to measure physical activity and short-term HRV in patients with ischemic heart disease who report hopelessness.

METHODS

We outline the study protocol for the standardization of reliable and rigorous physical activity and HRV data collection using the ActiGraph wGT3X-BT and Polar H7 Bluetooth heart rate monitor, and data analysis using ActiLife and Kubios software programs.

RESULTS

Sixty-four participants enrolled in the randomized controlled trial to date, and 45 (70.3%) have completed or are actively participating in the study. Heart rate variability data have been collected on 43 of the 45 participants (96%) to date. During the first data collection time point, 42 of 44 participants (95.5%) wore the ActiGraph for a minimum of 5 valid days, followed by 28 of 31 participants (90.3%) and 25 of 26 participants (96.2%) at subsequent data collection time points. The intraclass correlation for physical activity in this study is 0.95 and 0.98 for HRV.

DISCUSSION

Revisions to the protocol were successfully implemented at the onset of the COVID-19 pandemic for data collection using social distancing. The protocol was additionally amended in response to an unanticipated problem with ActiGraph battery life using Bluetooth technology. Use of the ActiGraph HRV protocol has led to a reliable and rigorous measurement of physical activity and HRV for patients with ischemic heart disease who report hopelessness in this randomized controlled trial.

CONCLUSION

We provide an ActiGraph HRV protocol that can be adapted as a model in the development of ActiGraph HRV protocols for future nursing research in community and home-based settings while maximizing social distancing in the current and future pandemics.

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).

Accelerometer-Measured Sedentary and Physical Activity Time and Their Correlates in European Older Adults: The SITLESS Study

Background

Sedentary behavior (SB) and physical activity (PA) are important determinants of health in older adults. This study aimed to describe the composition of accelerometer-measured SB and PA in older adults, to explore self-reported context-specific SB, and to assess sociodemographic and functional correlates of engaging in higher levels of SB in participants of a multicenter study including four European countries.

Method

One thousand three hundred and sixty community-dwelling older adults from the SITLESS study (61.8% women; 75.3 ± 6.3 years) completed a self-reported SB questionnaire and wore an ActiGraph accelerometer for 7 days. Accelerometer-determined compositional descriptive statistics were calculated. A fixed-effects regression analysis was conducted to assess the sociodemographic (country, age, sex, civil status, education, and medications) and functional (body mass index and gait speed) correlates.

Results

Older adults spent 78.8% of waking time in SB, 18.6% in light-intensity PA, and 2.6% in moderate-to-vigorous PA. Accelerometry showed that women engaged in more light-intensity PA and walking and men engaged in higher amounts of moderate-to-vigorous PA. Watching television and reading accounted for 47.2% of waking time. Older age, being a man, single, taking more medications, being obese and overweight, and having a slower gait speed were statistically significant correlates of more sedentary time.

Conclusions

The high amount of SB of our participants justifies the need to develop and evaluate interventions to reduce sitting time. A clinically relevant change in gait speed can decrease almost 0.45 percentage points of sedentary time. The distribution of context-specific sedentary activities by country and sex showed minor differences, albeit worth noting.

Construct validity of the brief physical activity assessment tool for clinical use in COPD

INTRODUCTION

Low physical activity (PA) levels are associated with poor health-related outcomes in Chronic Obstructive Pulmonary Disease (COPD). Thus, PA should be routinely assessed in clinical practice.

OBJECTIVES

This study assessed the construct validity of the Brief Physical Activity Assessment Tool (BPAAT) for clinical use in COPD and explored differences in age, sex and COPD grades.

METHODS

After linguistic adaptation of the tool to Portuguese, 110 patients (66.4 ± 9.6yrs, 72.7% male, FEV₁  = 59.3 ± 25.5%predicted) completed the BPAAT and received an accelerometer. The BPAAT includes two questions assessing the weekly frequency and duration of vigorous- and moderate-intensity PA/walking, classifying individuals as insufficiently or sufficiently active. The BPAAT was correlated with accelerometry (moderate PA, MPA = 1952-5724 counts-per-min [CPM]); vigorous PA, VPA = 5725-∞CPM; moderate-to-vigorous PA, MVPA = 1952-∞CPM; daily steps), through: Spearman's correlations (ρ) for continuous data; %agreement, Kappa, sensitivity and specificity, positive and negative predictive values (PPV, NPV) for categorical data.

RESULTS

The BPAAT identified 73.6% patients as "insufficiently active" and 26.4% as "sufficiently active". The BPAAT was weakly to moderately correlated with accelerometry (0.394 ≤ ρ ≤ 0.435, P < 0.05), except for VPA (P = 0.440). This was also observed in age (<65/≥65yrs), COPD grades (GOLD 1-2/3-4) and in male patients (0.363 ≤ ρ ≤ 0.518, P < 0.05 except for VPA). No significant correlations were found in female patients (P > 0.05). Agreement was fair to moderate (0.36 ≤ κ ≤ 0.43; 73.6% ≤ %agreement ≤ 74.5%; 0.50 ≤ sensitivity ≤ 0.52; 0.84 ≤ specificity ≤ 0.91, 0.55 ≤ PPV ≤ 0.79, 0.72 ≤ NPV ≤ 0.82).

CONCLUSION

The BPAAT may be useful to screen patients' PA, independently of age and COPD grade, and identify male patients who are insufficiently active. Care should be taken when using this tool to assess vigorous PA or female patients.

Towards a better understanding of physical activity in people with COPD: predicting physical activity after pulmonary rehabilitation using an integrative competence model

The integrative Physical Activity-related Health Competence (PAHCO) model specifies competences (movement competence, control competence, and self-regulation competence) that enable people to lead a physically active lifestyle. This longitudinal study analyses the predictive quality of a multidimensional PAHCO assessment for levels of physical activity (PA) and their relevance for quality of life in COPD patients after pulmonary rehabilitation. At the end of an inpatient pulmonary rehabilitation (T2), 350 COPD patients participating in the Stay Active after Rehabilitation (STAR) study underwent assessments, including a six-factor measurement of PAHCO. PA (triaxial accelerometry) and quality of life (Saint George's Respiratory Questionnaire) were recorded 6 weeks (T3) and 6 months (T4) after rehabilitation. Structural equation modelling (SEM) was used to regress the PAHCO assessment on PA, which should, in turn, influence quality of life. In univariable analysis, five and six factors of the PAHCO model were related to PA and quality of life, respectively. Multivariate modelling showed that the predictive analyses for the PA level were dominated by the 6-minute walking test representing movement competence (0.562 ≤ |β| ≤ 0.599). Affect regulation as an indicator of control competence co-predicted quality of life at T3 and levels of PA at T4. The PA level was, in turn, significantly associated with patients' quality of life (0.306 ≤ |β| ≤ 0.388). The integrative PAHCO model may be used as a theoretical framework for predicting PA in COPD patients following pulmonary rehabilitation. The results improve our understanding of PA behaviour in COPD patients and bear implications for person-oriented PA promotion.

The Impact of Pulmonary Rehabilitation on 24-Hour Movement Behavior in People With Chronic Obstructive Pulmonary Disease: New Insights From a Compositional Perspective

BACKGROUND

Physical activity levels are low in people with chronic obstructive pulmonary disease, and there is limited knowledge about how pulmonary rehabilitation transforms movement behaviors. This study analyzed data from a pulmonary rehabilitation trial and identified determinants of movement behaviors.

METHODS

Objectively assessed time in daily movement behaviors (sleep, sedentary, light-intensity physical activity, and moderate- to vigorous-intensity physical activity) from a randomized controlled trial (n = 73 participants) comparing home- and center-based pulmonary rehabilitation was analyzed using conventional and compositional analytical approaches. Regression analysis was used to assess relationships between movement behaviors, participant features, and response to the interventions.

RESULTS

Compositional analysis revealed no significant differences in movement profiles between the home- and center-based groups. At end rehabilitation, conventional analyses identified positive relationships between exercise capacity (6-min walk distance), light-intensity physical activity, and moderate- to vigorous-intensity physical activity time. Compositional analyses identified positive relationships between a 6-minute walk distance and moderate- to vigorous-intensity physical activity time, accompanied by negative relationships with sleep and sedentary time (relative to other time components) and novel relationships between body mass index and light-intensity physical activity/sedentary time.

CONCLUSION

Compositional analyses following pulmonary rehabilitation identified unique associations between movement behaviors that were not evident in conventional analyses.

Twitter-Based Social Support Added to Fitbit Self-Monitoring for Decreasing Sedentary Behavior: Protocol for a Randomized Controlled Pilot Trial With Female Patients From a Women's Heart Clinic

Background

Prolonged sitting is an independent risk behavior for the development of chronic disease. With most interventions focusing on physical activity and exercise, there is a separate need for investigation into innovative and accessible interventions to decrease sedentary behavior throughout the day. Twitter is a social media platform with application for health communications and fostering of social support for health behavior change.

Objective

This pilot study aims to test the feasibility, acceptability, and preliminary efficacy of delivering daily behavior change strategies within private Twitter groups to foster peer-to-peer support and decrease sedentary behavior throughout the day in women. The Twitter group was combined with a Fitbit for self-monitoring activity and compared to a Fitbit-only control group.

Methods

In a 2-group design, participants were randomized to a Twitter + Fitbit treatment group or a Fitbit-only control group. Participants were recruited via the Stanford Research Repository System, screened for eligibility, and then invited to an orientation session. After providing informed consent, they were randomized. All participants received 13 weeks of tailored weekly step goals and a Fitbit. The treatment group participants, placed in a private Twitter support group, received daily automated behavior change “tweets” informed by theory and regular automated encouragement via text to communicate with the group. Fitbit data were collected daily throughout the treatment and follow-up period. Web-based surveys and accelerometer data were collected at baseline, treatment end (13 weeks), and at 8.5 weeks after the treatment.

Results

The initial study design funding was obtained from the Women’s Heart Clinic and the Stanford Clayman Institute. Funding to run this pilot study was received from the National Institutes of Health’s National Heart, Lung, and Blood Institute under Award Number K01HL136702. All procedures were approved by Stanford University’s Institutional Review Board, #32127 in 2018, prior to beginning data collection. Recruitment for this study was conducted in May 2019. Of the 858 people screened, 113 met the eligibility criteria, 68 came to an information session, and 45 consented to participate in this pilot study. One participant dropped out of the intervention, and complete follow-up data were obtained from 39 of the 45 participants (87% of the sample). Data were collected over 6 months from June to December 2019. Feasibility, acceptability, and preliminary efficacy results are being analyzed and will be reported in the winter of 2021.

Conclusions

This pilot study is assessing the feasibility, acceptability, and preliminary efficacy of delivering behavior change strategies in a Twitter social support group to decrease sedentary behavior in women. These findings will inform a larger evaluation. With an accessible, tailorable, and flexible platform, Twitter-delivered interventions offer potential for many treatment variations and titrations, thereby testing the effects of different behavior change strategies, peer-group makeups, and health behaviors of interest.

Trial Registration

ClinicalTrials.gov NCT02958189, https://clinicaltrials.gov/ct2/show/NCT02958189

International Registered Report Identifier (IRRID)

DERR1-10.2196/20926

The Path Forward for Digital Measures: Suppressing the Desire to Compare Apples and Pineapples

Digital measures are becoming more prevalent in clinical development. Methods for robust evaluation are increasingly well defined, yet the primary barrier for digital measures to transition beyond exploratory usage often relies on a comparison to the existing standards. This article focuses on how researchers should approach the complex issue of comparing across assessment modalities. We discuss comparisons of subjective versus objective assessments, or performance-based versus behavioral measures, and we pay particular attention to the situation where the expected association may be poor or nonlinear. We propose that, rather than seeking to replace the standard, research should focus on a structured understanding of how the new measure augments established assessments, with the ultimate goal of developing a more complete understanding of what is meaningful to patients.

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 Use of Inertial Measurement Units for the Study of Free Living Environment Activity Assessment: A Literature Review

This article presents an overview of fifty-eight articles dedicated to the evaluation of physical activity in free-living conditions using wearable motion sensors. This review provides a comprehensive summary of the technical aspects linked to sensors (types, number, body positions, and technical characteristics) as well as a deep discussion on the protocols implemented in free-living conditions (environment, duration, instructions, activities, and annotation). Finally, it presents a description and a comparison of the main algorithms and processing tools used for assessing physical activity from raw signals.

Development of Novel, Value-Based, Digital Endpoints for Clinical Trials: A Structured Approach Toward Fit-for-Purpose Validation

Novel digital endpoints gathered via wearables, small devices, or algorithms hold great promise for clinical trials. However, implementation has been slow because of a lack of guidelines regarding the validation process of these new measurements. In this paper, we propose a pragmatic approach toward selection and fit-for-purpose validation of digital endpoints. Measurements should be value-based, meaning the measurements should directly measure or be associated with meaningful outcomes for patients. Devices should be assessed regarding technological validity. Most importantly, a rigorous clinical validation process should appraise the tolerability, difference between patients and controls, repeatability, detection of clinical events, and correlation with traditional endpoints. When technically and clinically fit-for-purpose, case building in interventional clinical trials starts to generate evidence regarding the response to new or existing health-care interventions. This process may lead to the digital endpoint replacing traditional endpoints, such as clinical rating scales or questionnaires in clinical trials. We recommend initiating more data-sharing collaborations to prevent unnecessary duplication of research and integration of value-based measurements in clinical care to enhance acceptance by health-care professionals. Finally, we invite researchers and regulators to adopt this approach to ensure a timely implementation of digital measurements and value-based thinking in clinical trial design and health care. SIGNIFICANCE STATEMENT: Novel digital endpoints are often cited as promising for the clinical trial of the future. However, clear validation guidelines are lacking in the literature. This paper contains pragmatic criteria for the selection, technical validation, and clinical validation of novel digital endpoints and provides recommendations for future work and collaboration.

First-Line Treatment with Tiotropium/Olodaterol Improves Physical Activity in Patients with Treatment-Naïve Chronic Obstructive Pulmonary Disease

Background

Comparative effects on physical activity of mono and dual bronchodilators remain unclear in patients with treatment-naïve chronic obstructive pulmonary disease (COPD). We sought to compare the changes in physical activity before and after tiotropium and tiotropium/olodaterol treatment in treatment-naïve COPD patients.

Methods

A prospective, multicenter, randomized, open-labeled, and parallel interventional study was conducted. Eighty Japanese patients with treatment-naïve COPD were randomized to receive either tiotropium or tiotropium/olodaterol treatment for 12 weeks. Spirometry and dyspnea index were assessed, and COPD assessment test (CAT) and the 6-minute walk distance (6MWD) were conducted before and after treatment. Evaluation of physical activity was assessed by a triaxle accelerometer over a 2-week period before and after treatment.

Results

There were no differences in the mean age (69.8 vs 70.4 years), body mass index (BMI) (22.5 vs 22.6 kg/m²) and mean % forced expiratory volume in 1 second (%FEV1) at baseline (61.5 vs 62.6%) between the two groups. Changes in FEV1 (mean±standard error, 242.8±28.8 mL) and transient dyspnea index (TDI) (2.4±0.3 points) before and after tiotropium/olodaterol treatment were greater than with tiotropium treatment (104.1±31.9 mL, p<0.01 and 1.5±0.3, p=0.02, respectively). Changes in the duration of physical activity with 1.0–1.5 metabolic equivalents (METs) estimated in the sedentary position following tiotropium/olodaterol treatment (−38.7±14.7 min) tended to be reduced more than with tiotropium treatment (−4.6±10.6 min) (p=0.06), although those with ≥2.0 METs numerically increased with both treatments (+10.8±7.6 min for tiotropium/olodaterol vs +8.3±7.6 min for tiotropium, p=0.82). Tiotropium/olodaterol treatment reduced the duration of physical activity with 1.0–1.5 METs (regression coefficient, −43.6 [95% CI −84.1, −3.1], p=0.04) in a multiple regression model adjusted for cofounding factors such as age, FEV1, total CAT scores, 6MWD, and TDI.

Conclusion

This is the first study to report the impact of dual bronchodilator on physical activity in treatment-naïve COPD patients of Japanese with low BMI.

Digital Measures That Matter to Patients: A Framework to Guide the Selection and Development of Digital Measures of Health

Background

With the rise of connected sensor technologies, there are seemingly endless possibilities for new ways to measure health. These technologies offer researchers and clinicians opportunities to go beyond brief snapshots of data captured by traditional in-clinic assessments, to redefine health and disease. Given the myriad opportunities for measurement, how do research or clinical teams know what they should be measuring? Patient engagement, early and often, is paramount to thoughtfully selecting what is most important. Regulators encourage stakeholders to have a patient focus but actionable steps for continuous engagement are not well defined. Without patient-focused measurement, stakeholders risk entrenching digital versions of poor traditional assessments and proliferating low-value tools that are ineffective, burdensome, and reduce both quality and efficiency in clinical care and research.

Summary

This article synthesizes and defines a sequential framework of core principles for selecting and developing measurements in research and clinical care that are meaningful for patients. We propose next steps to drive forward the science of high-quality patient engagement in support of measures of health that matter in the era of digital medicine.

Key Messages

All measures of health should be meaningful, regardless of the product's regulatory classification, type of measure, or context of use. To evaluate meaningfulness of signals derived from digital sensors, the following four-level framework is useful: Meaningful Aspect of Health, Concept of Interest, Outcome to be measured, and Endpoint (exclusive to research). Incorporating patient input is a dynamic process that requires more than a single, transactional touch point but rather should be conducted continuously throughout the measurement selection process. We recommend that developers, clinicians, and researchers reevaluate processes for more continuous patient engagement in the development, deployment, and interpretation of digital measures of health.

Advances in accelerometry for cardiovascular patients: a systematic review with practical recommendations

Aims

Accelerometers are becoming increasingly commonplace for assessing physical activity; however, their use in patients with cardiovascular diseases is relatively substandard. We aimed to systematically review the methods used for collecting and processing accelerometer data in cardiology, using the example of heart failure, and to provide practical recommendations on how to improve objective physical activity assessment in patients with cardiovascular diseases by using accelerometers.

Methods and results

Four electronic databases were searched up to September 2019 for observational, interventional, and validation studies using accelerometers to assess physical activity in patients with heart failure. Study and population characteristics, details of accelerometry data collection and processing, and description of physical activity metrics were extracted from the eligible studies and synthesized. To assess the quality and completeness of accelerometer reporting, the studies were scored using 12 items on data collection and processing, such as the placement of accelerometer, days of data collected, and criteria for non‐wear of the accelerometer. In 60 eligible studies with 3500 patients (of those, 536 were heart failure with preserved ejection fraction patients), a wide variety of accelerometer brands (n = 27) and models (n = 46) were used, with Actigraph being the most frequent (n = 12), followed by Fitbit (n = 5). The accelerometer was usually worn on the hip (n = 32), and the most prevalent wear period was 7 days (n = 22). The median wear time required for a valid day was 600 min, and between two and five valid days was required for a patient to be included in the analysis. The most common measures of physical activity were steps (n = 20), activity counts (n = 15), and time spent in moderate‐to‐vigorous physical activity (n = 14). Only three studies validated accelerometers in a heart failure population, showing that their accuracy deteriorates at slower speeds. Studies failed to report between one and six (median 4) of the 12 scored items, with non‐wear time criteria and valid day definition being the most underreported items.

Conclusions

The use of accelerometers in cardiology lacks consistency and reporting on data collection, and processing methods need to be improved. Furthermore, calculating metrics based on raw acceleration and machine learning techniques is lacking, opening the opportunity for future exploration. Therefore, we encourage researchers and clinicians to improve the quality and transparency of data collection and processing by following our proposed practical recommendations for using accelerometers in patients with cardiovascular diseases, which are outlined in the article.

Determining Minimum Wear Time for Mobile Sensor Technology

Part 1 in the DIA Study Endpoint Community Working Group on Mobile Sensor Technology (MST) series addresses considerations that may be useful when determining the minimum wear time associated with mobile sensor use to ensure reliable estimation of the clinical endpoint under consideration. What constitutes a minimum valid data set is a dilemma facing those using MSTs in clinical studies. If this alignment does not occur, the integrity of the data collected and conclusions drawn from these data may be in incorrect. While study participants should consent to engage with MSTs as defined in a protocol, participant behavior or technology lapses may result in capturing incomplete data. Drawing from the literature, we review what constitutes a minimum data set, the risks associated with missing data, alignment with the clinical endpoint(s) and goals of a study, as well as managing patient burden.