Gait differences between COPD and healthy controls: systematic review and meta-analysis.

BACKGROUND: Despite the importance of gait as a determinant of falls, disability and mortality in older people, understanding of gait impairment in COPD is limited. This study aimed to identify differences in gait characteristics during supervised walking tests between people with COPD and healthy controls. METHODS: We searched 11 electronic databases, supplemented by Google Scholar searches and manual collation of references, in November 2019 and updated the search in July 2021. Record screening and information extraction were performed independently by one reviewer and checked for accuracy by a second. Meta-analyses were performed in studies not considered at a high risk of bias. RESULTS: Searches yielded 21 085 unique records, of which 25 were included in the systematic review (including 1015 people with COPD and 2229 healthy controls). Gait speed was assessed in 17 studies (usual speed: 12; fast speed: three; both speeds: two), step length in nine, step duration in seven, cadence in six, and step width in five. Five studies were considered at a high risk of bias. Low-quality evidence indicated that people with COPD walk more slowly than healthy controls at their usual speed (mean difference (MD) -19 cm·s-1, 95% CI -28 to -11 cm·s-1) and at a fast speed (MD -30 cm·s-1, 95% CI -47 to -13 cm·s-1). Alterations in other gait characteristics were not statistically significant. CONCLUSION: Low-quality evidence shows that people with COPD walk more slowly than healthy controls, which could contribute to an increased falls risk. The evidence for alterations in spatial and temporal components of gait was inconclusive. Gait impairment appears to be an important but understudied area in COPD.

The Association between Objectively Measured Physical Activity and the Prevalence of Comorbidities in Lung Transplant Recipients.

INTRODUCTION: Lung transplant recipients are often physically inactive and are at risk of developing comorbidities. We investigated whether objectively measured physical activity was associated with the prevalence of comorbidities. METHODS: Physical activity (accelerometry) and the presence of cardiovascular disease, symptoms of depression and anxiety, diabetes, dyslipidaemia, hypertension, lower extremity artery disease, muscle weakness, obesity, and osteoporosis were assessed in 108 lung transplant recipients. Patients were divided into four groups based on daily step count. RESULTS: A cohort of 108 patients (60 ± 7 years, 51% male, 20 ± 14 months since transplantation) was included. Active patients (>7,500 steps/day) had significantly fewer comorbidities (4 comorbidities) compared to severely inactive patients (<2,500 steps/day, 6 comorbidities), and muscle weakness and high symptoms of depression were less prevalent. Severely inactive patients had significantly more cardiovascular comorbidities compared to all other groups. No other significant differences were observed. CONCLUSION: Physically active lung transplant recipients have fewer comorbidities, lower prevalence of muscle weakness, and fewer symptoms of depression compared to very inactive patients.

Physical activity coaching in patients with interstitial lung diseases: A randomized controlled trial.

OBJECTIVES: Physical activity is reduced in patients with interstitial lung disease (ILD) and physical inactivity is related to poor health outcomes. We investigated the effect of a telecoaching intervention to improve physical activity in patients with ILD. METHODS: Eighty patients with ILD were randomized into the intervention or control group. Patients in the intervention group received a 12-week telecoaching program including a step counter, a patient-tailored smartphone application, and coaching calls. Patients in the control group received usual care. Physical activity (primary outcome), physical fitness and quality of life were measured at baseline and 12 weeks later with an accelerometer, 6-min walking test and quadriceps muscle force and the King's Brief Interstitial Lung Disease questionnaire (K-BILD). RESULTS: Participation in telecoaching did not improve physical activity: between-group differences for step count: 386 ± 590 steps/day, p = .52; sedentary time: 4 ± 18 min/day, p = .81; movement intensity: 0.04 ± 0.05 m/s2, p = .45). Between-group differences for the 6-min walking test, quadriceps muscle force and K-BILD were 14 ± 10 m, p = .16; 2 ± 3% predicted, p = .61; 0.8 ± 1.7 points, p = .62 respectively. CONCLUSIONS: Twelve weeks of telecoaching did not improve physical activity, physical fitness or quality of life in patients with ILD. Future physical or behavioural interventions are needed for these patients to improve physical activity.

Development and feasibility of an exercise training program in primary care for patients with COPD experiencing an acute exacerbation.

BACKGROUND: Starting rehabilitation soon after an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is crucial to diminish the detrimental effects of this acute event on muscle function. However, uptake in outpatient pulmonary rehabilitation is low. OBJECTIVES: To design and test a feasible, acceptable and accessible exercise training program (ETP) in primary care for patients experiencing an AECOPD. DESIGN: (1) A literature review and qualitative study to develop an ETP and (2) A feasibility study of the ETP implemented in primary care. METHODS: (1) The development of the ETP proceeded in several phases with input from different stakeholders through focus group discussions. (2) Patients experiencing a moderate or severe AECOPD were included and followed the ETP for two weeks with a physiotherapist in primary care. Interviews with the participants took place and patients were given the choice to complete the eight-week program. RESULTS: (1) Six discussion sessions took place. The ETP contained a flexible set of progressively more difficult exercises applicable in a primary care practice. (2) Eight patients experiencing a moderate (n = 1) or severe (n = 7) AECOPD were included. Patients started the first physiotherapy session 5 (2-6) days after the start of their symptoms or hospital discharge. Seven patients wanted to complete the ETP. CONCLUSIONS: An ETP in primary care is feasible, acceptable and accessible for patients experiencing a moderate or severe AECOPD, and for physiotherapists. The effectiveness of this ETP on muscle function and physical activity is currently under investigation in a RCT. CONTRIBUTION OF THE PAPER.

Investigating the prognostic value of digital mobility outcomes in patients with chronic obstructive pulmonary disease: a systematic literature review and meta-analysis.

BACKGROUND: Reduced mobility is a central feature of COPD. Assessment of mobility outcomes that can be measured digitally (digital mobility outcomes (DMOs)) in daily life such as gait speed and steps per day is increasingly possible using devices such as pedometers and accelerometers, but the predictive value of these measures remains unclear in relation to key outcomes such as hospital admission and survival. METHODS: We conducted a systematic review, nested within a larger scoping review by the MOBILISE-D consortium, addressing DMOs in a range of chronic conditions. Qualitative and quantitative analysis considering steps per day and gait speed and their association with clinical outcomes in COPD patients was performed. RESULTS: 21 studies (6076 participants) were included. Nine studies evaluated steps per day and 11 evaluated a measure reflecting gait speed in daily life. Negative associations were demonstrated between mortality risk and steps per day (per 1000 steps) (hazard ratio (HR) 0.81, 95% CI 0.75-0.88, p<0.001), gait speed (<0.80 m·s-1) (HR 3.55, 95% CI 1.72-7.36, p<0.001) and gait speed (per 1.0 m·s-1) (HR 7.55, 95% CI 1.11-51.3, p=0.04). Fewer steps per day (per 1000) and slow gait speed (<0.80 m·s-1) were also associated with increased healthcare utilisation (HR 0.80, 95% CI 0.72-0.88, p<0.001; OR 3.36, 95% CI 1.42-7.94, p=0.01, respectively). Available evidence was of low-moderate quality with few studies eligible for meta-analysis. CONCLUSION: Daily step count and gait speed are negatively associated with mortality risk and other important outcomes in people with COPD and therefore may have value as prognostic indicators in clinical trials, but the quantity and quality of evidence is limited. Larger studies with consistent methodologies are called for.

The association of weather conditions with day-to-day variability in physical activity in patients with COPD.

Background: While patients with COPD often cite weather conditions as a reason for inactivity, little is known about the relationship between physical activity (PA) and weather conditions. The present study investigated the association of day-to-day weather changes on PA in patients with COPD and investigated patient characteristics related to being more or less influenced by weather conditions. Methods: In this longitudinal analysis, device-based day-by-day step counts were objectively measured in COPD patients for up to 12 months. Daily meteorological data (temperature, precipitation, wind speed, hours of sunlight and daylight) were linked to the daily step count and individual and multivariable relationships were investigated using mixed-model effects. Individual R2 was calculated for every subject to investigate the estimated influence of weather conditions on a patient level and its relationship with patient characteristics. Results: We included 50 patients with a mean±sd follow-up time of 282±93 days, totalling 14 117 patient-days. Daily temperature showed a positive linear pattern up until an inflexion point, after which a negative association with increasing temperature was observed (p<0.0001). Sunshine and daylight time had a positive association with PA (p<0.0001). Precipitation and wind speed were negatively associated with PA (p<0.0001). The median per-patient R2 for overall weather conditions was 0.08, ranging from 0.00 to 0.42. No strong associations between patient characteristics and per-patient R2 were observed. Conclusion: Weather conditions are partly associated with PA in patients with COPD, yet the overall explained variance of PA due to weather conditions is rather low and varied strongly between individuals.

Factors associated to physical activity in patients with COPD: An ecological approach.

BACKGROUND: Physical activity (PA) is low in patients with Chronic Obstructive Pulmonary Disease (COPD). Identifying modifiable and non-modifiable correlates of PA give understanding of the individual behavior and provide future directions for PA enhancing interventions. As PA is complex and multidimensional, it should be embedded within a thorough framework. OBJECTIVE: To identify correlates of PA in a comprehensive COPD population based on a broad ecological model, including physiological, psychological, socio-demographic and environmental dimensions. METHODS: PA was objectively measured using the Dynaport Movemonitor and a comprehensive data collection of physiological, psychological, socio-demographic and environmental factors were collected. Bivariable and multivariable regression analyses (including principle component analysis) were executed. RESULTS: For this cross-sectional analysis, we included 148 patients with COPD and valid PA data (mean (SD) age 68 (7) years, FEV1 57 (17) % predicted, 5613 (3596) steps per day). Significant bivariable associations were found for physiological (exercise capacity, muscle force, lung function, symptoms, comorbidities), psychological (e.g. fatigue, motivation, perceived difficulty with PA), socio-demographic (dog owning, use of activity tracker) and environmental (season, daylight, temperature) factors. Based on the multivariable regression model, exercise capacity, beliefs on motivation, importance and self-confidence regarding PA and weather conditions were independent correlates of mean steps per day (R2 = 0.35). Movement intensity during walking was only independently associated with exercise capacity and age (R2 = 0.41). CONCLUSION: Although a wide range of potential influence factors were evaluated, variance in PA was only partly explained, supporting that PA is a complex behavior which is difficult to predict.

In-hospital rehabilitation with the Geriatric Activation Program Pellenberg improves functional performance in a heterogeneous geriatric population.

BACKGROUND: Regaining independent living can be challenging in patients undergoing inpatient geriatric rehabilitation. Given the paucity of evidence-based physiotherapy programs for this particular heterogeneous group, the Geriatric Activation Program Pellenberg (GAPP) was developed. PURPOSE: Investigate the evolution of functional performance, and predict detectable changes throughout 4 weeks of GAPP. Methods: Participants in this observational study (2017-2019) followed GAPP as part of their rehabilitation program. Functional balance (Berg balance scale (BBS)) and independence (Katz scale) were the primary outcomes, with gait speed, elbow and knee extension strength, cognitive processing speed, and mood as secondary outcomes. All outcomes were assessed at baseline, 2 weeks and 4 weeks later. Prediction analysis was conducted using logistic regression modeling. Previously reported minimal detectable change with 95% confidence interval (MDC95) was used as detectable change. RESULTS: We recruited 111 participants, with 83 completing 4 weeks of GAPP and all assessments. Over 4 weeks, all outcome measures showed a significant improvement (p ≤ .007). Detectable change was found for BBS (mean improvement of 12.8 points (95% CI: 10.9-14.8), MDC95 = 6.6) and gait speed (mean improvement of 0.24 m/s (95% CI: 0.19-0.29), MDC95 = 0.1 m/s). We found that baseline scores lower than 26 on the BBS (75% sensitivity, 65% specificity) and gait speed lower than 0.34 m/s (53% sensitivity, 81% specificity) were associated with participants achieving detectable change at 4 weeks on BBS and gait speed, respectively. CONCLUSION: Functional performance of a heterogeneous group of geriatric inpatients improved notably after 4 weeks of GAPP. Baseline scores on BBS and gait speed can partially predict detectable changes in functional performance.

Physical activity pattern of patients with interstitial lung disease compared to patients with COPD: A propensity-matched study.

INTRODUCTION: Physical activity (PA) is reduced in patients with interstitial lung disease (ILD) and chronic obstructive pulmonary disease (COPD). Evidence about the PA pattern of patients with ILD is scarce. If PA of patients with ILD would be comparable to COPD, it is tempting to speculate that existing interventions focusing on enhancing PA could be as effective in ILD as already shown in COPD. Therefore, we aimed to compare PA and the correlates with PA in matched patients with ILD, COPD, and healthy subjects. MATERIALS AND METHODS: Patients with ILD (n = 45), COPD (n = 45) and healthy subjects (n = 30) were propensity matched. PA level, pattern, and PA correlations with lung function and physical performance (6-minute walking distance and quadriceps force) were compared between groups. RESULTS: Daily number of steps was similar in both patient groups (mean±SE: 5631±459 for ILD, 5544±547 for COPD, p = 0.900), but significantly lower compared to healthy subjects (10031±536, p<0.001 for both). Mean intensity of PA tended to be lower in the ILD group (mean±SE metabolic equivalents of task per day: 1.41±0.04) compared to COPD (1.52±0.05, p = 0.074) and healthy individuals (1.67±0.04, p<0.001). The pattern of PA over one day was found to be similar between the three groups. Lastly, the correlation between PA and 6-minute walking distance was significantly weaker in patients with ILD compared to patients with COPD (respectively r = 0.348 and r = 0.739; p<0.05 for both). CONCLUSIONS: For a given functional reserve, patients with ILD perform an equal amount of steps but perform PA at lower intensity compared to patients with COPD. Both groups are less active compared to healthy control subjects. Functional exercise capacity was shown to be only moderately related to PA. This can potentially influence the effectiveness of PA interventions that can be expected.

Walking on common ground: a cross-disciplinary scoping review on the clinical utility of digital mobility outcomes.

Physical mobility is essential to health, and patients often rate it as a high-priority clinical outcome. Digital mobility outcomes (DMOs), such as real-world gait speed or step count, show promise as clinical measures in many medical conditions. However, current research is nascent and fragmented by discipline. This scoping review maps existing evidence on the clinical utility of DMOs, identifying commonalities across traditional disciplinary divides. In November 2019, 11 databases were searched for records investigating the validity and responsiveness of 34 DMOs in four diverse medical conditions (Parkinson's disease, multiple sclerosis, chronic obstructive pulmonary disease, hip fracture). Searches yielded 19,672 unique records. After screening, 855 records representing 775 studies were included and charted in systematic maps. Studies frequently investigated gait speed (70.4% of studies), step length (30.7%), cadence (21.4%), and daily step count (20.7%). They studied differences between healthy and pathological gait (36.4%), associations between DMOs and clinical measures (48.8%) or outcomes (4.3%), and responsiveness to interventions (26.8%). Gait speed, step length, cadence, step time and step count exhibited consistent evidence of validity and responsiveness in multiple conditions, although the evidence was inconsistent or lacking for other DMOs. If DMOs are to be adopted as mainstream tools, further work is needed to establish their predictive validity, responsiveness, and ecological validity. Cross-disciplinary efforts to align methodology and validate DMOs may facilitate their adoption into clinical practice.

Can COPD Exacerbations Be Picked Up Early via a Weekly Medication Question Through a Smartphone Application?

Background: Exacerbations affect the disease trajectory of patients with COPD and result in an acute drop of functional status and physical activity. Timely detection of exacerbations by non-medical healthcare professionals is needed to counteract this decline. The use of digital health applications in patient interaction allows embedded detection of exacerbations. However, it is unknown if this is an effective way to pick up exacerbations. Method: We investigated the detection of exacerbations in patients with COPD enrolled in a physical activity coaching program, by prompting a weekly question on changes in medication via the smartphone application. Data on response rate and occurrence of exacerbations were collected. Results: Response rate to the medication question, evaluated in 42 patients, was 72% (n = 497). A change in medication was reported through the smartphone application in 38 (7.6%) of the answered questions. The response rate was significantly lower at 6 months follow-up compared to the first month (p =0.03). When evaluating the occurrence of adverse events in a subset of patients who completed 6 months of follow-up (n = 27), 18 exacerbations were registered in eight patients, of which 10 of these exacerbations (56%) were picked up by the medication question in the coaching application. Conclusion: Electronic interaction through a weekly medication question, embedded in a smartphone application, is feasible to support the detection of the occurrence of COPD exacerbations and can be used complementary to regular forms of detecting exacerbations. Compliance and smartphone literacy should be optimized when further using this method to report on COPD exacerbations.