The PROactive instruments to measure physical activity in patients with chronic obstructive pulmonary disease

Measurement of physical activity in clinical practice and research: advances in cancer and chronic respiratory disease

PURPOSE OF REVIEW

Physical activity has emerged as an important health outcome and its assessment, in particular with objective monitors, has proliferated in recent years. This review considers recent advances in physical activity measurement and clinical trials in cancer and chronic respiratory diseases where physical activity was a primary or key secondary outcome focusing on methodological learning points.

RECENT FINDINGS

There is growing data on (i) the validity of commercial 'consumer' physical activity monitors, e.g. FitBit, and (ii) the role of hybrid physical activity assessments; combining objective and subjective measures to understand physical activity quantity and quality. In both cases, adherence is challenging and can be optimized using short monitoring protocols, e.g., 3-4 days, and by providing clear instructions and support materials to participants. Studies in cancer and chronic respiratory disease have found mixed effects from physical activity interventions based on pedometers, behavior change techniques, online resources, and/or therapeutic nutrition. The most responsive physical activity outcomes and minimum clinically important differences are still to be understood.

SUMMARY

Physical activity measures provide an opportunity to detect changes in health behavior. However, measuring physical activity as a trial endpoint is challenging and focusing effort to ensure optimal participant compliance is important.

Physical Inactivity in Pulmonary Sarcoidosis

PURPOSE

Reduced physical activity in many chronic diseases is consistently associated with increased morbidity. Little is known about physical activity in sarcoidosis. The aim of this study was to objectively assess physical activity in patients with pulmonary sarcoidosis and investigate its relationship with lung function, exercise capacity, symptom burden, and health status.

METHODS

Physical activity was assessed over one week in 15 patients with pulmonary sarcoidosis and 14 age-matched healthy controls with a tri-axial accelerometer (ActivPal™) and the International Physical Activity Questionnaire (IPAQ). All participants underwent pulmonary function tests, 6-min walk test (6MWT) and completed the Fatigue Assessment Scale (FAS), Medical Research Council (MRC) Dyspnoea Scale and the King's Sarcoidosis Questionnaire (KSQ).

RESULTS

Patients with sarcoidosis had significantly lower daily step counts than healthy controls; mean (SD) 5624 (1875) versus 10,429 (2942) steps (p < 0.01) and a trend towards fewer sit-to-stand transitions each day (p = 0.095). Only two patients (13%) self-reported undertaking vigorous physical activity (IPAQ) compared to half of healthy individuals (p < 0.01). Daily step count was significantly associated with 6MWT distance in sarcoidosis (r = 0.634, p = 0.01), but not with forced vital capacity (r = 0.290), fatigue (r = 0.041), dyspnoea (r = -0.466) or KSQ health status (r = 0.099-0.484). Time spent upright was associated with fatigue (r = -0.630, p = 0.012) and health status (KSQ Lung scores r = 0.524, p = 0.045), and there was a significant correlation between the number of sit-to-stand transitions and MRC dyspnoea score (r = -0.527, p = 0.044).

CONCLUSION

Physical activity is significantly reduced in sarcoidosis and is associated with reduced functional exercise capacity (6MWD). Fatigue, exertional symptoms and health status were more closely associated with time spent upright and the number of bouts of physical activity, as compared to step counts. Further studies are warranted to identify the factors that determine different physical activity profiles in sarcoidosis.

Determinants of study completion and response to a 12-month behavioral physical activity intervention in chronic obstructive pulmonary disease: A cohort study

OBJECTIVES

Physical activity is key to improve the prognosis of chronic obstructive pulmonary disease (COPD). To help to tailor future interventions we aimed to identify the baseline characteristics of COPD patients which predict 12-month completion and response to a behavioral physical activity intervention.

METHODS

This is a 12-month cohort study of the intervention arm of the Urban Training randomized controlled trial (NCT01897298), an intervention proven to be efficacious to increase physical activity. We considered baseline sociodemographic, interpersonal, environmental, clinical and psychological characteristics as potential determinants of completion and response. We defined completion as attending the 12-month study visit. Among completers, we defined response as increasing physical activity ≥1100 steps/day from baseline to 12 months, measured by accelerometer. We estimated the factors independently for completion and response using multivariable logistic regression models.

RESULTS

Of a total of 202 patients (m (SD) 69 (9) years, 84% male), 132 (65%) completed the study. Among those, 37 (28%) qualified as responders. Higher numbers of baseline steps/day (OR [95% CI] 1.11 [1.02-1.21] per increase of 1000 steps, p<0.05) and living with a partner (2.77 [1.41-5.48], p<0.01) were related to a higher probability of completion while more neighborhood vulnerability (0.70 [0.57-0.86] per increase of 0.1 units in urban vulnerability index, p<0.01) was related to a lower probability. Among the completers, working (3.14 [1.05-9.33], p<0.05) and having an endocrino-metabolic disease (4.36 [1.49-12.80], p<0.01) were related to a higher probability of response while unwillingness to follow the intervention (0.21 [0.05-0.98], p<0.05) was related to a lower probability.

CONCLUSIONS

This study found that 12-month completion of a behavioral physical activity intervention was generally determined by previous physical activity habits as well as interpersonal and environmental physical activity facilitators while response was related to diverse factors thought to modify the individual motivation to change to an active lifestyle.

Activity monitors in pulmonary disease

Physical activity is reduced in patients with chronic pulmonary diseases. Activity monitors can measure physical activity objectively and accurately over prolonged periods of time. Research grade and commercially available devices, using accelerometer technology, are being increasingly used in clinical studies. Physical activity levels have been found to have a moderate to strong correlation with important measures such as pulmonary function, exercise capacity, quality of life, and mortality and hospitalizations in patients with COPD, interstitial lung disease, pulmonary arterial hypertension and cystic fibrosis. Their use as a clinical trial end-point and as a tool to augment rehabilitation efforts has also been explored in patients with COPD with variable results. Due to the ease of use, economic viability, widespread availability and good patient compliance, their use in adult and pediatric medicine is expanding. This narrative review summarizes the current evidence of use of activity monitors in COPD, interstitial lung disease, asthma, pulmonary arterial hypertension, cystic fibrosis and lung transplant patients for the purposes of prognostication, monitoring, outcome measures and intervention.

Changes in physical activity during hospital admission for chronic respiratory disease

BACKGROUND AND OBJECTIVE

Establishing the amount of inpatient physical activity (PA) undertaken by individuals hospitalized for chronic respiratory disease is needed to inform interventions. This observational study investigated whether PA changes when a person is an inpatient, how long is required to obtain representative PA measures and whether PA varies within a day and between patients of differing lengths of stay.

METHODS

A total of 389 participants were recruited as early as possible into their hospitalization. Patients wore a PA monitor from recruitment until discharge. Step count was extracted for a range of wear time criteria. Single-day intraclass correlation coefficients (ICC) were calculated, with an ICC ≥ 0.80 deemed acceptable.

RESULTS

PA data were available for 259 participants. No changes in daily step count were observed during the inpatient stay (586 (95% CI: 427-744) vs 652 (95% CI: 493-812) steps/day for day 2 and 7, respectively). ICC across all wear time criteria were > 0.80. The most stringent wear time criterion, retaining 80% of the sample, was ≥11 h on ≥1 day. More steps were taken during the morning and afternoon than overnight and evening. After controlling for the Medical Research Council (MRC) grade or oxygen use, there was no difference in step count between patients admitted for 2-3 days (short stay) and those admitted for 7-14 days (long stay).

CONCLUSION

Patients move little during their hospitalization, and inpatient PA did not increase during their stay. A wear time criterion of 11 waking hours on any single day was representative of the entire admission whilst retaining an acceptable proportion of the initial sample size. Patients may need encouragement to move more during their hospital stay.

Effects of a long-term home-based exercise training programme using minimal equipment vs. usual care in COPD patients: a study protocol for two multicentre randomised controlled trials (HOMEX-1 and HOMEX-2 trials)

BACKGROUND

Exercise training is an important component of pulmonary rehabilitation (PR) programmes in chronic obstructive pulmonary disease (COPD), but the great majority of COPD patients who would benefit from PR never follow such programmes or fail to maintain exercise training after PR completion. Against this background, we developed an exercise training programme that requires minimal equipment and can be implemented long-term in the patient's home-setting. The aims of the HOMEX-1 and HOMEX-2 trials are to assess the effectiveness of this home-based exercise training programme in two groups of COPD patients over the course of one year: patients who have completed PR (HOMEX-1 trial) and patients who did not enrol in existing PR programmes within the last two years (HOMEX-2 trial).

METHODS

HOMEX-1 and HOMEX-2 are multicentre, parallel group, randomised controlled trials. For both trials each, it is planned to include 120 study participants with a diagnosis of COPD. Participants will be randomised with a 1:1 ratio into the intervention group or the control group (usual care/no intervention). The intervention consists of minimal-equipment exercise training elements with progressive level of intensity, conducted by the participant during six days per week and instructed and coached by a trained health care professional during three home visits and regular telephone calls during one year. Primary outcome is change in dyspnoea (domain of Chronic Respiratory Questionnaire) from baseline to 12-months follow-up. Secondary outcomes are change in dyspnoea over the course of the year (assessed at 3, 6 and 12 month) and change in functional exercise capacity, physical activity, health-related quality of life, health status, exacerbations and symptoms from baseline to 12 months follow-up. In addition, explanatory, safety and cost-effectiveness outcomes will be assessed. We will conduct intention-to-treat analyses separately per trial and per protocol analyses as sensitivity analyses.

DISCUSSION

The HOMEX-1 and HOMEX-2 trials assess a novel intervention that provides an innovative way of making exercise training as accessible as possible for COPD patients. If the intervention proves to be effective long-term, it will fill the gap of providing an easily accessible and feasible intervention so that more COPD patients can follow an exercise programme.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: HOMEX-1 NCT03461887 (registration date: March 12, 2018; retrospectively registered); HOMEX-2 NCT03654092 (registration date: August 31, 2018).

Real-world use of rescue inhaler sensors, electronic symptom questionnaires and physical activity monitors in COPD

Background

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterised by airflow obstruction and other morbidities such as respiratory symptoms, reduced physical activity and frequent bronchodilator use. Recent advances in personal digital monitoring devices can permit continuous collection of these data in COPD patients, but the relationships among them are not well understood.

Methods

184 individuals from a single centre of the COPDGene cohort agreed to participate in this 3-week observational study. Each participant used a smartphone to complete a daily symptom diary (EXAcerbations of Chronic pulmonary disease Tool, EXACT), wore a wrist-worn accelerometer to record continuously physical activity and completed the Clinical Visit PROactive Physical Activity in COPD questionnaire. 58 users of metered dose inhalers for rescue (albuterol) were provided with an inhaler sensor, which time stamped each inhaler actuation.

Results

Rescue inhaler use was strongly correlated with E-RS:COPD score, while step counts were correlated with neither rescue use nor E-RS:COPD score. Frequent, unpatterned inhaler use pattern was associated with worse respiratory symptoms and less physical activity compared with frequent inhaler use with a regular daily pattern. There was a strong week-by-week correlation among measurements, suggesting that 1 week of monitoring is sufficient to characterise stable patients with COPD.

Discussion

The study highlights the interaction and relevance of personal real-time monitoring of respiratory symptoms, physical activity and rescue medication in patients with COPD. Additionally, visual displays of longitudinal data may be helpful for disease management to help drive conversations between patients and caregivers and for risk-based monitoring in clinical trials.

Functional status measures for the COPD patient: A practical categorization

The objective of this study is to review available functional status measures (FSMs) validated for use in the chronic obstructive pulmonary disease (COPD) population and categorizing the measures by their commonalities to formulate a framework that supports clinicians in the selection and application of FSMs. A literature review identifying valid and reliable measures of functional status for people with COPD was undertaken. Measures were thematically analyzed and categorized to develop a framework for clinical application. A variety of measures of activity levels exist, with 35 included in this review. Thematic categorization identified five categories of measures: daily activity, impact, surrogate, performance-based, and disability-based measures. The vast variety of FSMs available for clinicians to apply with people who have COPD may be overwhelming, and selection must be thoughtfully based on the nature of the population being studied/evaluated, and aims of evaluation being conducted, not simply as a standard measure used at the institution. Psychometric testing is a critical feature to a strong instrument and issues of reliability, validity, and responsiveness need to be understood prior to measurement use. Contextual nature of measures such as language used and activities measured is also important. A categorical framework to support clinicians in the selection and application of FSMs has been presented in this article.

The once-daily fixed-dose combination of olodaterol and tiotropium in the management of COPD: current evidence and future prospects

Long-acting bronchodilators are the cornerstone of pharmacologic treatment of chronic obstructive pulmonary disease (COPD). Spiolto® or Stiolto® is a fixed-dose combination (FDC) containing two long-acting bronchodilators, the long-acting muscarinic receptor antagonist tiotropium (TIO) and the long-acting β2-adrenoceptor agonist olodaterol (OLO), formulated in the Respimat® Soft Mist™ inhaler. A total of 13 large, multicentre studies of up to 52 weeks' duration have documented its efficacy in more than 15,000 patients with COPD. TIO/OLO 5/5 µg FDC significantly increases pulmonary function compared with placebo and its respective constituent mono-components TIO 5 µg and OLO 5 µg. TIO/OLO 5/5 µg also results in statistically and clinically significant improvements in patient-reported outcomes, such as dyspnoea, use of rescue medication, and health status. Addition of OLO 5 µg to TIO 5 µg reduces the rate of moderate-to-severe exacerbations by approximately 10%. Compared with placebo and TIO 5 µg, TIO/OLO 5/5 µg significantly improves exercise capacity (e.g. endurance time) and physical activity, the latter increase being reached by a unique combination behavioural modification intervention, dual bronchodilatation and exercise training. Overall, the likelihood for patients to experience a clinically significant benefit is higher with TIO/OLO 5/5 µg than with its constituent mono-components, which usually yield smaller improvements which do not always reach statistical significance, compared with baseline or placebo. This supports the early introduction of TIO/OLO 5/5 µg in the management of patients with symptomatic COPD.

Long-term efficacy and effectiveness of a behavioural and community-based exercise intervention (Urban Training) to increase physical activity in patients with COPD: a randomised controlled trial

There is a need to increase and maintain physical activity in patients with chronic obstructive pulmonary disease (COPD). We assessed 12-month efficacy and effectiveness of the Urban Training intervention on physical activity in COPD patients.

This randomised controlled trial (NCT01897298) allocated 407 COPD patients from primary and hospital settings 1:1 to usual care (n=205) or Urban Training (n=202). Urban Training consisted of a baseline motivational interview, advice to walk on urban trails designed for COPD patients in outdoor public spaces and other optional components for feedback, motivation, information and support (pedometer, calendar, physical activity brochure, website, phone text messages, walking groups and a phone number). The primary outcome was 12-month change in steps·day⁻¹ measured by accelerometer.

Efficacy analysis (with per-protocol analysis set, n=233 classified as adherent to the assigned intervention) showed adjusted (95% CI) 12-month difference +957 (184–1731) steps·day⁻¹ between Urban Training and usual care. Effectiveness analysis (with intention-to-treat analysis set, n=280 patients completing the study at 12 months including unwilling and self-reported non-adherent patients) showed no differences between groups. Leg muscle pain during walks was more frequently reported in Urban Training than usual care, without differences in any of the other adverse events.

Urban Training, combining behavioural strategies with unsupervised outdoor walking, was efficacious in increasing physical activity after 12 months in COPD patients, with few safety concerns. However, it was ineffective in the full population including unwilling and self-reported non-adherent patients.

Urban Training in COPD increased physical activity after 12 months but not in self-reported non-adherent patientshttp://ow.ly/dc2C30lnAEs

CELEB trial: Comparative Effectiveness of Lung volume reduction surgery for Emphysema and Bronchoscopic lung volume reduction with valve placement: a protocol for a randomised controlled trial

INTRODUCTION

Although lung volume reduction surgery and bronchoscopic lung volume reduction with endobronchial valves have both been shown to improve lung function, exercise capacity and quality of life in appropriately selected patients with emphysema, there are no direct comparison data between the two procedures to inform clinical decision-making.

METHODS AND ANALYSIS

We describe the protocol of the CELEB study, a randomised controlled trial which will compare outcomes at 1 year between the two procedures, using a composite disease severity measure, the iBODE score, which includes body mass index, airflow obstruction, dyspnoeaand exercise capacity (incremental shuttle walk test).

ETHICS AND DISSEMINATION

Ethical approval to conduct the study has been obtained from the Fulham Research Ethics Committee, London (16/LO/0286). The outcome of this trial will provide information to guide treatment choices in this population and will be presented at national and international meetings and published in peer-reviewed journals. We will also disseminate the main results to all participants in a letter.

TRIAL REGISTRATION NUMBER

ISRCTN19684749; Pre-results.

Incorporating telemedicine into the integrated care of the COPD patient a summary of an interdisciplinary workshop held in Stresa, Italy, 7-8 September 2017

This report is a summary of a workshop focusing on using telemedicine to facilitate the integrated care of chronic obstructive pulmonary disease (COPD). Twenty-five invited participants from 8 countries met for one and one-half days in Stresa, Italy on 7-8 September 2017, to discuss this topic. Participants included physiotherapists, nurses, a nurse practitioner, and physicians. While evidence-based data are always at the center of sound inference and recommendations, at this point in time the science behind telemedicine in COPD remains under-developed; therefore, this document reflects expert opinion and consensus. While telemedicine has great potential to expand and improve the care of our COPD patients, its application is still in its infancy. While studies have demonstrated its effectiveness in some patient-centered outcomes, the results are by no means consistently positive. Whereas this tool may potentially reduce health care costs by moving some medical interventions from centralized locations in to patient's home, its cost-effectiveness has had mixed results and telemonitoring has yet to prove its worth in the COPD population. These discordant results should not be unexpected in view of patient complexity and the heterogeneity of telemedicine. This is reflected in the very limited support offered by the National Health Services to a wider application of telemedicine in the integrated care of COPD patients. However, this situation should challenge us to develop the necessary science to clarify the role of telemedicine in the medical management of our patients, providing a better and definitive scientific basis to this approach.

Redefining Cut-Points for High Symptom Burden of the Global Initiative for Chronic Obstructive Lung Disease Classification in 18,577 Patients With Chronic Obstructive Pulmonary Disease

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) can be classified into groups A/C or B/D based on symptom intensity. Different threshold values for symptom questionnaires can result in misclassification and, in turn, different treatment recommendations. The primary aim was to find the best fitting cut-points for Global initiative for chronic Obstructive Lung Disease (GOLD) symptom measures, with an modified Medical Research Council dyspnea grade of 2 or higher as point of reference.

METHODS

After a computerized search, data from 41 cohorts and whose authors agreed to provide data were pooled. COPD studies were eligible for analyses if they included, at least age, sex, postbronchodilator spirometry, modified Medical Research Council, and COPD Assessment Test (CAT) total scores.

MAIN OUTCOMES

Receiver operating characteristic curves and the Youden index were used to determine the best calibration threshold for CAT, COPD Clinical Questionnaire, and St. Georges Respiratory Questionnaire total scores. Following, GOLD A/B/C/D frequencies were calculated based on current cut-points and the newly derived cut-points.

FINDINGS

A total of 18,577 patients with COPD [72.0% male; mean age: 66.3 years (standard deviation 9.6)] were analyzed. Most patients had a moderate or severe degree of airflow limitation (GOLD spirometric grade 1, 10.9%; grade 2, 46.6%; grade 3, 32.4%; and grade 4, 10.3%). The best calibration threshold for CAT total score was 18 points, for COPD Clinical Questionnaire total score 1.9 points, and for St. Georges Respiratory Questionnaire total score 46.0 points.

CONCLUSIONS

The application of these new cut-points would reclassify about one-third of the patients with COPD and, thus, would impact on individual disease management. Further validation in prospective studies of these new values are needed.

Self-reported task-oriented physical activity: A comparison with objective daily step count in COPD

BACKGROUND

Low physical activity (PA) is associated with adverse health outcomes independent of airflow limitation in COPD. Self-reported assessments are often limited to global estimates of PA and may not be directly translatable to patients' goals and motivations. We developed a task-oriented PA checklist and examined its performance relative to pedometer-assessed daily step count in two COPD cohorts.

METHODS

Task-oriented daily physical activity (DPA) was assessed in two COPD cohorts using either interviewer-administered recall questionnaire (DPA-R, Cohort 1, n = 109) or a self-administered diary-format daily checklist (DPA-C, Cohort 2, n = 175). Daily step count was measured in both cohorts using the Omron HJ-720 ITC pedometer. Univariate associations between individual DPA items and [a] cross-sectional and [b] longitudinal change (Cohort 1) in daily step count were assessed using a Pearson's correlation. Composite scores comprised of individual DPA items with univariate association p-values <0.1 were tested for association with daily step count using multivariate models.

RESULTS

Tasks associated with average daily step count in both cohorts included putting on shoes, showering, washing hair, walking for exercise, the frequency of walks >10 min, and walking on an incline (Pearson's rho range = 0.14-0.43). A composite score of these 6 DPA items demonstrated significant associations with baseline average daily step count in both cohorts (ρ = 0.5 & 0.47, Cohorts 1 & 2, respectively) and longitudinal change in daily step count (ρ = 0.46, Cohort 1).

CONCLUSIONS

Self-reported task-oriented assessments complement direct monitoring and have potential clinical utility in exercise counseling to increase PA among COPD patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01772082.

The prevalence of patient engagement in published trials: a systematic review

PLAIN ENGLISH SUMMARY

With the growing movement to engage patients in research, questions are being asked about who is engaging patients and how they are being engaged. Internationally, research groups are supporting and funding patient-oriented research studies that engage patients in the identification of research priorities and the design, conduct and uptake of research. As we move forward, we need to know what meaningful patient engagement looks like, how it benefits research and clinical practice, and what are the barriers to patient engagement?We conducted a review of the published literature looking for trials that report engaging patients in the research. We included both randomized controlled trials and non-randomized comparative trials. We looked at these trials for important study characteristics, including how patients were engaged, to better understand the practices used in trials. Importantly, we also discuss the number of trials reporting patient engagement practices relative to all published trials. We found that very few trials report any patient engagement activities even though it is widely supported by many major funding organizations. The findings of our work will advance patient-oriented research by showing how patients can be engaged and by stressing that patient engagement practices need to be better reported.

BACKGROUND

Patient-Oriented Research (POR) is research informed by patients and is centred on what is of importance to them. A fundamental component of POR is that patients are included as an integral part of the research process from conception to dissemination and implementation, and by extension, across the research continuum from basic research to pragmatic trials [J Comp Eff Res 2012, 1:181-94, JAMA 2012, 307:1587-8]. Since POR's inception, questions have been raised as to how best to achieve this goal.We conducted a systematic review of randomized controlled trials and non-randomized comparative trials that report engaging patients in their research. Our main goal was to describe the characteristics of published trials engaging patients in research, and to identify the extent of patient engagement activities reported in these trials.

METHODS

The MEDLINE®, EMBASE®, Cinahl, PsycINFO, Cochrane Methodology Registry, and Pubmed were searched from May 2011 to June 16th, 2016. Title, abstract and full text screening of all reports were conducted independently by two reviewers. Data were extracted from included trials by one reviewer and verified by a second. All trials that report patient engagement for the purposes of research were included.

RESULTS

Of the 9490 citations retrieved, 2777 were reviewed at full text, of which 23 trials were included. Out of the 23 trials, 17 were randomized control trials, and six were non-randomized comparative trials. The majority of these trials (83%, 19/23) originated in the United States and United Kingdom. The trials engaged a range of 2-24 patients/ community representatives per study. Engagement of children and minorities occurred in 13% (3/23) and 26% (6/23) of trials; respectively. Engagement was identified in the development of the research question, the selection of study outcomes, and the dissemination and implementation of results.

CONCLUSIONS

The prevalence of patient engagement in patient-oriented interventional research is very poor with 23 trials reporting activities engaging patients. Research dedicated to determining the best practice for meaningful engagement is still needed, but adequate reporting measures also need to be defined.

ACTIVATE: the effect of aclidinium/formoterol on hyperinflation, exercise capacity, and physical activity in patients with COPD

The Phase IV, 8-week, randomized, double-blind, placebo-controlled ACTIVATE study (NCT02424344) evaluated the effect of aclidinium/formoterol (AB/FF) 400/12 μg twice daily on lung hyperinflation, exercise capacity, and physical activity in patients with moderate-to-severe COPD. Patients received AB/FF (n=134) or placebo (n=133) (1:1) via the Genuair™/Pressair^® dry powder inhaler for 8 weeks. From Weeks 5 to 8, all patients participated in behavioral intervention (BI; daily messages providing step goals). The primary end point was trough functional residual capacity (FRC) at Week 4. Exercise endurance time and physical activity were assessed at Week 4 (pharmacotherapy only) and at Week 8 (8 weeks of pharmacotherapy plus 4 weeks of BI). Other end points included post-dose FRC, residual volume, and inspiratory capacity (IC) at rest and during exercise. After 4 weeks, trough FRC improved with AB/FF versus placebo but did not reach significance (125 mL; P=0.0690). However, post-dose FRC, residual volume, and IC at rest improved significantly with AB/FF at Week 4 versus placebo (all P<0.0001). AB/FF significantly improved exercise endurance time and IC at isotime versus placebo at Week 4 (P<0.01 and P<0.0001, respectively) and Week 8 (P<0.05 and P<0.0001, respectively). AB/FF achieved higher step counts (P<0.01) with fewer inactive patients (P<0.0001) at Week 4 versus placebo. Following BI, AB/FF maintained improvements in physical activity at Week 8 and nonsignificant improvements were observed with placebo. AB/FF 400/12 μg demonstrated improvements in lung hyperinflation, exercise capacity, and physical activity versus placebo that were maintained following the addition of BI. A 4-week period of BI might be too short to augment the improvements of physical activity observed with AB/FF.

Physical activity in patients with COPD: the impact of comorbidities

INTRODUCTION

Comorbidities are common in patients with chronic obstructive pulmonary disease (COPD) and it plays an important role on physical activity (PA) in this population. Since low PA levels have been described as a key factor to predict morbi-mortality in COPD, it seems crucial to review the current literature available on this topic. Areas covered: This review covers the most common comorbidities found in COPD, their prevalence and prognostic implications. We explore the differences in PA between COPD patients with and without comorbidities, as well as the impact of the number or type of comorbidities on activity levels of this population. The effect of different comorbidities on activities of daily living in patients with COPD is also reviewed. Finally, we discuss options for the treatment of inactivity in COPD patients considering their comorbidities and limitations. Expert commentary: Comorbidities are highly prevalent in patients with COPD and further deteriorate PA levels in this population. Despite the wide range of interventions available in COPD, the evidence in the field seems to point at PA coaching with feedback on individual goals and longer lasting PR programmes with more than 12 weeks of duration when attempting to raise the activity levels of this population.

Accelerometer- versus questionnaire-based assessment of physical activity and their changes over time in patients with COPD

Background and objective

Physical activity (PA) is an important outcome parameter in patients with COPD regarding hospitalizations and mortality. Both objective assessment by accelerometers and self-evaluation by questionnaires were used in studies investigating PA in COPD. Whether self-reported questionnaires can adequately reflect PA and its changes over time compared to objective assessments has not been thoroughly investigated in COPD. In this COPD cohort study, we evaluated whether PA measured by accelerometer and its annual changes can also be assessed by self-reported questionnaires.

Methods

In 178 COPD patients with at least two assessments of PA, the agreement between objectively measured and self-reported activity was analyzed by Bland–Altman plots. Daily PA was assessed by a triaxial activity monitor over 1 week and by the self-reported German PA questionnaire 50+.

Results

Comparison between the two methods of measurement revealed no convincing agreement with a mean difference and limits of agreement (±1.96 standard deviation [SD]) of time spent in at least moderate PA (>3 metabolic equivalent of task [MET]) of −77.6 (−340.3/185.2) min/day, indicating a self-reported overestimation of PA by the questionnaire. The mean difference and limits of agreement (±1.96SD) in the annual change of PA was 1.2 min/day (−208.2/282.6 min/day), showing also a poor agreement on an individual level.

Conclusion

Evaluation of objectively measured and self-reported PA and their annual changes revealed no agreement in patients with COPD. Therefore, the evaluated questionnaire seems not helpful for measurement of PA and its changes over time.

Validity and reliability of strain gauge measurement of volitional quadriceps force in patients with COPD

This study investigated the validity and reliability of fixed strain gauge measurements of isometric quadriceps force in patients with chronic obstructive pulmonary disease (COPD). A total cohort of 138 patients with COPD were assessed. To determine validity, maximal volitional quadriceps force was evaluated during isometric maximal voluntary contraction (MVC) manoeuvre via a fixed strain gauge dynamometer and compared to (a) potentiated non-volitional quadriceps force obtained via magnetic stimulation of the femoral nerve (twitch (Tw); n = 92) and (b) volitional computerized dynamometry (Biodex; n = 46) and analysed via correlation coefficients. Test-retest and absolute reliability were determined via calculations of intra-class correlation coefficients (ICCs), smallest real differences (SRDs) and standard errors of measurement (SEMs). For this, MVC recordings in each device were performed across two test sessions separated by a period of 7 days ( n = 46). Strain gauge measures of MVC demonstrated very large correlation with Tw and Biodex results ( r = 0.86 and 0.88, respectively, both p < 0.0001). ICC, SEM and SRD were numerically comparable between strain gauge and Biodex devices (ICC = 0.96 vs. 0.93; SEM = 8.50 vs. 10.54 N·m and SRD = 23.59 vs. 29.22 N·m, respectively). The results support that strain gauge measures of quadriceps force are valid and reliable in patients with COPD.

Comparing accelerometer, pedometer and a questionnaire for measuring physical activity in bronchiectasis: a validity and feasibility study?

Background

There are challenges for researchers and clinicians to select the most appropriate physical activity tool, and a balance between precision and feasibility is needed. Currently it is unclear which physical activity tool should be used to assess physical activity in Bronchiectasis. The aim of this research is to compare assessment methods (pedometer and IPAQ) to our criterion method (ActiGraph) for the measurement of physical activity dimensions in Bronchiectasis (BE), and to assess their feasibility and acceptability.

Methods

Patients in this analysis were enrolled in a cross-sectional study. The ActiGraph and pedometer were worn for seven consecutive days and the IPAQ was completed for the same period. Statistical analyses were performed using SPSS 20 (IBM). Descriptive statistics were used; the percentage agreement between ActiGraph and the other measures were calculated using limits of agreement. Feedback about the feasibility of the activity monitors and the IPAQ was obtained.

Results

There were 55 (22 male) data sets available. For step count there was no significant difference between the ActiGraph and Pedometer, however, total physical activity time (mins) as recorded by the ActiGraph was significantly higher than the pedometer (mean ± SD, 232 (75) vs. 63 (32)). Levels of agreement between the two devices was very good for step count (97% agreement); and variation in the levels of agreement were within accepted limits of ±2 standard deviations from the mean value.

IPAQ reported more bouted- moderate - vigorous physical activity (MVPA) [mean, SD; 167(170) vs 6(9) mins/day], and significantly less sedentary time than ActiGraph [mean, SD; 362(115) vs 634(76) vmins/day]. There were low levels of agreement between the two tools (57% sedentary behaviour; 0% MVPA₁₀₊), with IPAQ under-reporting sedentary behaviour and over-reporting MVPA₁₀₊ compared to ActiGraph. The monitors were found to be feasible and acceptable by participants and researchers; while the IPAQ was accepta ble to use, most patients required assistance to complete it.

Conclusions

Accurate measurement of physical activity is feasible in BE and will be valuable for future trials of therapeutic interventions. ActiGraph or pedometer could be used to measure simple daily step counts, but ActiGraph was superior as it measured intensity of physical activity and was a more precise measure of time spent walking. The IPAQ does not appear to represent an accurate measure of physical activity in this population.

Trial registration

Clinical Trials Registration Number NCT01569009: Physical Activity in Bronchiectasis.

Oxygen for breathlessness in patients with chronic obstructive pulmonary disease who do not qualify for home oxygen therapy

BACKGROUND

Breathlessness is a cardinal symptom of chronic obstructive pulmonary disease (COPD). Long-term oxygen therapy (LTOT) is given to improve survival time in people with COPD and severe chronic hypoxaemia at rest. The efficacy of oxygen therapy for breathlessness and health-related quality of life (HRQOL) in people with COPD and mild or no hypoxaemia who do not meet the criteria for LTOT has not been established.

OBJECTIVES

To determine the efficacy of oxygen versus air in mildly hypoxaemic or non-hypoxaemic patients with COPD in terms of (1) breathlessness; (2) HRQOL; (3) patient preference whether to continue therapy; and (4) oxygen-related adverse events.

SEARCH METHODS

We searched the Cochrane Airways Group Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase, to 12 July 2016, for randomised controlled trials (RCTs). We handsearched the reference lists of included articles.

SELECTION CRITERIA

We included RCTs of the effects of non-invasive oxygen versus air on breathlessness, HRQOL or patient preference to continue therapy among people with COPD and mild or no hypoxaemia (partial pressure of oxygen (PaO₂) > 7.3 kPa) who were not already receiving LTOT. Two review authors independently assessed articles for inclusion in the review.

DATA COLLECTION AND ANALYSIS

Two review authors independently collected and analysed data. We assessed risk of bias by using the Cochrane 'Risk of bias tool'. We pooled effects recorded on different scales as standardised mean differences (SMDs) with 95% confidence intervals (CIs) using random-effects models. Lower SMDs indicated decreased breathlessness and reduced HRQOL. We performed subanalyses and sensitivity analyses and assessed the quality of evidence according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

MAIN RESULTS

Compared with the previous review, which was published in 2011, we included 14 additional studies (493 participants), excluded one study and included data for meta-analysis of HRQOL. In total, we included in this review 44 studies including 1195 participants, and we included 33 of these (901 participants)in the meta-analysis.We found that breathlessness during exercise or daily activities was reduced by oxygen compared with air (32 studies; 865 participants; SMD -0.34, 95% CI -0.48 to -0.21; I² = 37%; low-quality evidence). This translates to a decrease in breathlessness of about 0.7 points on a 0 to 10 numerical rating scale. In contrast, we found no effect of short-burst oxygen given before exercise (four studies; 90 participants; SMD 0.01, 95% CI -0.26 to 0.28; I² = 0%; low-quality evidence). Oxygen reduced breathlessness measured during exercise tests (25 studies; 442 participants; SMD -0.34, 95% CI -0.46 to -0.22; I² = 29%; moderate-quality evidence), whereas evidence of an effect on breathlessness measured in daily life was limited (two studies; 274 participants; SMD -0.13, 95% CI, -0.37 to 0.11; I² = 0%; low-quality evidence).Oxygen did not clearly affect HRQOL (five studies; 267 participants; SMD 0.10, 95% CI -0.06 to 0.26; I² = 0%; low-quality evidence). Patient preference and adverse events could not be analysed owing to insufficient data.

AUTHORS' CONCLUSIONS

We are moderately confident that oxygen can relieve breathlessness when given during exercise to mildly hypoxaemic and non-hypoxaemic people with chronic obstructive pulmonary disease who would not otherwise qualify for home oxygen therapy. Most evidence pertains to acute effects during exercise tests, and no evidence indicates that oxygen decreases breathlessness in the daily life setting. Findings show that oxygen does not affect health-related quality of life.

Multimorbidity, frailty and chronic obstructive pulmonary disease: Are the challenges for pulmonary rehabilitation in the name?

The overwhelming majority of people with chronic obstructive pulmonary disease (COPD) have at least one coexisting medical condition often conceptualized as 'comorbidities'. These coexisting conditions vary in severity and impact; it is likely that for some patients, COPD is not their most important or severe condition. The concepts of multimorbidity and frailty may be useful to understand the broader needs of people with COPD undergoing pulmonary rehabilitation. Multimorbidity describes the coexistence of two or more chronic conditions, without reference to a primary condition. Best care for people with multimorbidity has been described as a shift from providing disease-focused to patient-centred care. Pulmonary rehabilitation is well placed to deliver such care as it focuses on optimizing function, encourages integration across care settings, values input from multidisciplinary teams and measures patient-important outcomes. When designing optimal pulmonary rehabilitation services for people with multimorbidity, the concept of frailty may be useful. Frailty focuses on impairments rather than medical conditions including impairments in mobility, strength, balance, cognition, nutrition, endurance, mood and physical activity. Emerging data suggest that frailty may be modifiable with pulmonary rehabilitation. The challenge for pulmonary rehabilitation clinicians is to broaden our perspective on the role and outcomes of pulmonary rehabilitation for people with multimorbidity.

Plasma Fibrinogen Qualification as a Drug Development Tool in Chronic Obstructive Pulmonary Disease. Perspective of the Chronic Obstructive Pulmonary Disease Biomarker Qualification Consortium

The COPD Foundation Biomarker Qualification Consortium (CBQC) is a unique public-private partnership established in 2010 between the COPD Foundation, the pharmaceutical industry, and academic chronic obstructive pulmonary disease (COPD) experts with advisors from the U.S. NHLBI and the Food and Drug Administration (FDA). This was a direct response to the 2009 publication of a guidance on qualification of drug development tools by the FDA. Although data were believed to be available from publicly funded and industry-funded studies that could support qualification of several tools, the necessary data resided in disparate databases. The initial intent of the CBQC was to integrate these data and submit a dossier for the qualification. This led to the FDA qualification of plasma fibrinogen as a prognostic or enrichment biomarker for all-cause mortality and COPD exacerbations in July 2015. It is the first biomarker drug development tool qualified for use in COPD under the FDA's drug development tool qualification program. This perspective summarizes the FDA's qualification process, the formation of the CBQC, and the effort that led to a successful outcome for plasma fibrinogen and discusses implications for future biomarker qualification efforts.

Determinants of Physical Activity in Patients with Chronic Obstructive Pulmonary Disease: A 5-Year Prospective Follow-Up Study

BACKGROUND

Although many studies examined determinants of physical activity in patients with chronic obstructive pulmonary disease (COPD), most were cross-sectional and focused on single determinants only.

OBJECTIVES

The aim of this study was to determine how COPD patients' physical activity changes over time and to identify the determinants of physical activity using multivariable and longitudinal methods.

METHODS

In a prospective cohort study, 409 primary care patients with COPD in the Netherlands and Switzerland were followed for up to 5 years. Physical activity was assessed at baseline and every 6 months using the Longitudinal Aging Study Amsterdam Physical Activity Questionnaire (LAPAQ) adapted to a 0- to 23-point scale. We studied the associations between determinants at baseline and patients' long-term physical activity levels using linear mixed models.

RESULTS

Unadjusted analysis showed an overall gradual decline in physical activity (0.22 points of the LAPAQ scale every 6 months, 95% CI: 0.17-0.28; p < 0.001). In multivariable analyses, baseline determinants that were independently associated (p ≤ 0.05) with lower long-term physical activity levels included (starting from coefficients with the smallest p value) lower exercise capacity, older age, working, more smoking pack-years, more fatigued, male sex, lower educational levels, previously not in fitness programs, more depressed, lower lung function, lower overall health status, and more prescription drug use.

CONCLUSIONS

We found that physical activity of COPD patients may decline more than reported in the healthy elderly. Longitudinal analysis identified independent determinants of physical activity, which allows the identification of patients having low physical activity levels and who may benefit from physical activity interventions.

Depression symptoms reduce physical activity in COPD patients: a prospective multicenter study

Background

The role of anxiety and depression in the physical activity (PA) of patients with COPD is controversial. We prospectively assessed the effect of symptoms of anxiety and depression on PA in COPD patients.

Methods

We evaluated anxiety and depression (Hospital Anxiety and Depression Scale [HADS]), PA (Dynaport^® accelerometer), and other relevant characteristics in 220 COPD patients from five European countries at baseline and at 6 and 12 months of follow-up. HADS score was categorized as: no symptoms (score 0–7), suggested (8–10), and probable (>11) anxiety or depression. We estimated the association between anxiety and depression at t (baseline and 6 months) and PA at t+1 (6 and 12 months) using regression models with a repeated measures approach.

Results

Patients had a mean (standard deviation) age of 67 (8) years, forced expiratory volume in 1 second 57 (20)% predicted. At baseline, the prevalence of probable anxiety and depression was 10% and 5%, respectively. In multivariable models adjusted by confounders and previous PA, patients performed 81 fewer steps/day (95% confidence interval, −149 to −12, P=0.02) per extra point in HADS-depression score. HADS-anxiety symptoms were not associated with PA.

Conclusion

In COPD patients, symptoms of depression are prospectively associated with a measurable reduction in PA 6 months later.

The Minimal Important Difference in Physical Activity in Patients with COPD

BACKGROUND

Changes in physical activity (PA) are difficult to interpret because no framework of minimal important difference (MID) exists. We aimed to determine the minimal important difference (MID) in physical activity (PA) in patients with Chronic Obstructive Pulmonary Disease and to clinically validate this MID by evaluating its impact on time to first COPD-related hospitalization.

METHODS

PA was objectively measured for one week in 74 patients before and after three months of rehabilitation (rehabilitation sample). In addition the intraclass correlation coefficient was measured in 30 patients (test-retest sample), by measuring PA for two consecutive weeks. Daily number of steps was chosen as outcome measurement. Different distribution and anchor based methods were chosen to calculate the MID. Time to first hospitalization due to an exacerbation was compared between patients exceeding the MID and those who did not.

RESULTS

Calculation of the MID resulted in 599 (Standard Error of Measurement), 1029 (empirical rule effect size), 1072 (Cohen's effect size) and 1131 (0.5SD) steps.day-1. An anchor based estimation could not be obtained because of the lack of a sufficiently related anchor. The time to the first hospital admission was significantly different between patients exceeding the MID and patients who did not, using the Standard Error of Measurement as cutoff.

CONCLUSIONS

The MID after pulmonary rehabilitation lies between 600 and 1100 steps.day-1. The clinical importance of this change is supported by a reduced risk for hospital admission in those patients with more than 600 steps improvement.

Enhancing exercise tolerance and physical activity in COPD with combined pharmacological and non-pharmacological interventions: PHYSACTO randomised, placebo-controlled study design

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is associated with exercise limitation and physical inactivity, which are believed to have significant long-term negative health consequences for patients. While a number of COPD treatments and exercise training programmes increase exercise capacity, there is limited evidence for their effects on physical activity levels, with no clear association between exercise capacity and physical activity in clinical trials. Physical activity depends on a number of behaviour, environmental and physiological factors. We describe the design of the PHYSACTO trial, which is investigating the effects of bronchodilators, either alone or with exercise training, in combination with a standardised behaviour-change self-management programme, on exercise capacity and physical activity in patients with COPD. It is hypothesised that bronchodilators in conjunction with a behaviour-change self-management programme will improve physical activity and that this effect will be amplified by the addition of exercise training.

METHODS AND ANALYSIS

Patients are being recruited from 34 sites in Australia, New Zealand, the USA, Canada and Europe. Patients receiving a multicomponent intervention designed to support behaviour change related to physical activity are randomised to four treatment arms: placebo, tiotropium, tiotropium+olodaterol, and tiotropium+olodaterol+exercise training. The primary outcome is improvement in exercise capacity after 8 weeks, measured by endurance time during a shuttle walk test. The secondary outcome is improvement in physical activity, including objective accelerometer assessment and patient-reported functioning using the Functional Performance Inventory-Short Form and the novel hybrid PROactive instrument. Additionally, the influence of moderating variables (ie, factors influencing a patient's choice to be physically active) on increases in physical activity is also explored.

ETHICS AND DISSEMINATION

The study has been approved by the relevant Institutional Review Boards, Independent Ethics Committee and Competent Authority according to national and international regulations. The findings of the trial will be disseminated through relevant peer-reviewed journals and international conference presentations.

TRIAL REGISTRATION NUMBER

NCT02085161.

Physical Activity Characteristics across GOLD Quadrants Depend on the Questionnaire Used

BACKGROUND

The GOLD multidimensional classification of COPD severity combines the exacerbation risk with the symptom experience, for which 3 different questionnaires are permitted. This study investigated differences in physical activity (PA) in the different GOLD quadrants and patient's distribution in relation to the questionnaire used.

METHODS

136 COPD patients (58±21% FEV1 predicted, 34F/102M) completed COPD assessment test (CAT), clinical COPD questionnaire (CCQ) and modified Medical Research Council (mMRC) questionnaire. Exacerbation history, spirometry and 6MWD were collected. PA was objectively measured for 2 periods of 1 week, 6 months apart, in 5 European centres; to minimise seasonal and clinical variation the average of these two periods was used for analysis.

RESULTS

GOLD quadrants C+D had reduced PA compared with A+B (3824 [2976] vs. 5508 [4671] steps.d-1, p<0.0001). The choice of questionnaire yielded different patient distributions (agreement mMRC-CAT κ = 0.57; CCQ-mMRC κ = 0.71; CCQ-CAT κ = 0.72) with different clinical characteristics. PA was notably lower in patients with an mMRC score ≥2 (3430 [2537] vs. 5443 [3776] steps.d-1, p <0.001) in both the low and high risk quadrants.

CONCLUSIONS

Using different questionnaires changes the patient distribution and results in different clinical characteristics. Therefore, standardization of the questionnaire used for classification is critical to allow comparison of different studies using this as an entry criterion.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT01388218.

COPD: the patient perspective

Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease characterized by nonreversible airway obstruction. Well-characterized symptoms such as exertional dyspnea and fatigue have a negative impact on patients' quality of life (QoL) and restrict physical activity in daily life. The impact of COPD symptoms on QoL is often underestimated; for example, 36% of patients who describe their symptoms as being mild-to-moderate also admit to being too breathless to leave the house. Additionally, early morning and nighttime symptoms are a particular problem. Methods are available to allow clinicians to accurately assess COPD symptoms, including patient questionnaires. Integrated approaches to COPD management, particularly pulmonary rehabilitation, are effective strategies for addressing symptoms, improving exercise capacity and, potentially, also increasing physical activity. Inhaled bronchodilators continue to be the mainstay of drug therapy in COPD, where options can be tailored to meet patients' needs with careful selection of the inhaled medication and the device used for its delivery. Overall, an integrated approach to disease management should be considered for improving QoL and subsequent patient outcomes in COPD.

Patient reported outcome measures in chronic obstructive pulmonary disease: Which to use?

Patient-reported outcomes (PROs), such as symptoms and perceived health status, are essential in chronic obstructive pulmonary disease (COPD) for determining disease severity, impact on daily life, effect of treatment and recovery from exacerbations. This field has evolved rapidly and there are a plethora of instruments assessing different PROs. The aim of this review is to provide an understanding of the concept of PROs in COPD. The PROs reflect important aspects of COPD which have a direct impact on daily life. Common symptoms such as dyspnea, cough, phlegm, anxiety, fatigue, and pain and as well as physical function and the risk for and occurrence of acute exacerbations should be assessed both in the clinic and in research. Besides impact on daily life, some of the PROs are related to disease progress and mortality. Construction of composite variables including different disease specific and generic PROs provide a general estimation of health status.

Comparative study of linear and curvilinear ultrasound probes to assess quadriceps rectus femoris muscle mass in healthy subjects and in patients with chronic respiratory disease

Introduction

Ultrasound measurements of rectus femoris cross-sectional area (RF_CSA) are clinically useful measurements in chronic obstructive pulmonary disease (COPD) and critically ill patients. Technical considerations as to the type of probe used, which affects image resolution, have limited widespread clinical application. We hypothesised that measurement of RF_CSA would be similar with linear and curvilinear probes.

Methods

Four studies were performed to compare the use of the curvilinear probe in measuring RF_CSA. Study 1 investigated agreement of RF_CSA measurements using linear and curvilinear probes in healthy subjects, and in patients with chronic respiratory disease. Study 2 investigated the intra-rater and inter-rater agreement using the curvilinear probe. Study 3 investigated the agreement of RF_CSA measured from whole and spliced images using the linear probe. Study 4 investigated the applicability of ultrasound in measuring RF_CSA during the acute and recovery phases of an exacerbation of COPD.

Results

Study 1 showed demonstrated no difference in the measurement of RF_CSA using the curvilinear and linear probes (308±104 mm² vs 320±117 mm², p=0.80; intraclass correlation coefficient (ICC)>0.97). Study 2 demonstrated high intra-rater and inter-rater reliability of RF_CSA measurement with ICC>0.95 for both. Study 3 showed that the spliced image from the linear probe was similar to the whole image RF_CSA (308±103.5 vs 263±147 mm², p=0.34; ICC>0.98). Study 4 confirmed the clinical acceptability of using the curvilinear probe during an exacerbation of COPD. There were relationships observed between admission RF_CSA and body mass index (r=+0.65, p=0.018), and between RF_CSA at admission and physical activity levels at 4 weeks post-hospital discharge (r=+0.75, p=0.006).

Conclusions

These studies have demonstrated that clinicians can employ whole and spliced images from the linear probe or use images from the curvilinear probe, to measure RF_CSA. This will extend the clinical applicability of ultrasound in the measurement of muscle mass in all patient groups.