Gait speed and readmission following hospitalisation for acute exacerbations of COPD: a prospective study

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

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

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.

Digital measurement of mobility in pulmonary arterial hypertension: A structured review of an emerging area

This review examined literature that has examined mobility in pulmonary arterial hypertension (PAH) using digital technology. Specifically, the review focussed on: (a) digital mobility measurement in PAH; (b) commonly reported mobility outcomes in PAH; (c) PAH specific impact on mobility outcomes; and (d) recommendations concerning protocols for mobility measurement in PAH. PubMed, Scopus, and Medline databases were searched. Two independent reviewers screened articles that described objective measurement of mobility in PAH using digital technology. Twenty-one articles were screened, and 16 articles met the inclusion/exclusion criteria and were reviewed. Current methodologies for mobility measurement in PAH with digital technologies are discussed. In brief, the reviewed evidence demonstrated that there is a lack of standardisation across studies for instrumentation, outcomes, and interpretation in PAH. The validity and reliability of digital approaches were insufficiently reported in all studies. Future research is required to standardise digital mobility measurement and characterise mobility impairments in PAH across clinical and real-world settings. The reviewed evidence suggests that digital mobility outcomes may be useful clinical measures and may be impaired in PAH, but further research is required to accurately and robustly establish findings. Recommendations are provided for future studies that encompass comprehensive reporting, validation, and measurement.

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.

Physical status, symptoms and health-related quality of life during a severe exacerbation of COPD: Recovery and discriminative capacity for future events

OBJECTIVE

Severe acute exacerbations of chronic obstructive pulmonary disease (AECOPD) can have a negative impact on functional capacity, symptoms and health-related quality of life (HRQOL). This study aimed to i) investigate the recovery of muscle strength, functional capacity, symptoms, and HRQOL in patients after a severe AECOPD; ii) compare with matched patients with stable COPD (SCOPD); and iii) assess whether these assessments at hospital discharge could discriminate patients' risk for future events.

METHODS

This observational study assessed patients with AECOPD during hospital discharge (T1) and one month after discharge (T2). Patients with SCOPD were assessed once. Quadriceps force, handgrip strength, short physical performance battery (SPPB), 6-min walk distance (6 MWD), COPD assessment test (CAT), London chest activity of daily living (LCADL), modified medical research council, checklist individual strength-fatigue, patient health questionnaire, and physical activity (Actigraph) were measured. Exacerbation-related readmission and mortality within six months and 1-year were collected.

RESULTS

Forty-four patients with AECOPD were matched with 44 patients with SCOPD. At T2, a significant improvement was found for the SPPB total score, 6 MWD, CAT score, and LCADL score. Compared to patients with SCOPD, a worse LCADL score was found at T2 in patients with AECOPD. Patients with AECOPD that were readmitted or died had a worse SPPB classification and five-repetition sit-to-stand test at T1.

CONCLUSION

Patients after severe AECOPD improved in functional capacity and HRQOL one month after hospital discharge, but ADL performance was still worse compared to SCOPD. Patients who were readmitted or died had significantly worse scores on functional tests at hospital discharge.

Change in gait speed and adverse outcomes in patients with idiopathic pulmonary fibrosis: A prospective cohort study

BACKGROUND AND OBJECTIVE

Gait speed is associated with survival in individuals with idiopathic pulmonary fibrosis (IPF). The extent to which four-metre gait speed (4MGS) decline predicts adverse outcome in IPF remains unclear. We aimed to examine longitudinal 4MGS change and identify a cut-point associated with adverse outcome.

METHODS

In a prospective cohort study, we recruited 132 individuals newly diagnosed with IPF and measured 4MGS change over 6 months. Death/first hospitalization at 6 months were composite outcome events. Complete data (paired 4MGS plus index event) were available in 85 participants; missing 4MGS data were addressed using multiple imputation. Receiver-Operating Curve plots identified a 4MGS change cut-point. Cox proportional-hazard regression assessed the relationship between 4MGS change and time to event.

RESULTS

4MGS declined over 6 months (mean [95% CI] change: -0.05 [-0.09 to -0.01] m/s; p = 0.02). A decline of 0.07 m/s or more in 4MGS over 6 months had better discrimination for the index event than change in 6-minute walk distance, forced vital capacity, Composite Physiologic Index or Gender Age Physiology index. Kaplan-Meier curves demonstrated a significant difference in time to event between 4MGS groups (substantial decline: >-0.07 m/s versus minor decline/improvers: ≤-0.07 m/s; p = 0.007). Those with substantial decline had an increased risk of hospitalization/death (adjusted hazard ratio [95% CI] 4.61 [1.23-15.83]). Similar results were observed in multiple imputation analysis.

CONCLUSION

In newly diagnosed IPF, a substantial 4MGS decline over 6 months is associated with shorter time to hospitalization/death at 6 months. 4MGS change has potential as a surrogate endpoint for interventions aimed at modifying hospitalization/death.

Rehabilitation for People with Respiratory Disease and Frailty: An Official American Thoracic Society Workshop Report

People with respiratory disease have increased risk of developing frailty, which is associated with worse health outcomes. There is growing evidence of the role of rehabilitation in managing frailty in people with respiratory disease. However, several challenges remain regarding optimal methods of identifying frailty and delivering rehabilitation for this population. The aims of this American Thoracic Society workshop were to outline key definitions and concepts around rehabilitation for people with respiratory disease and frailty, synthesize available evidence, and explore how programs may be adapted to align to the needs and experiences of this population. Across two half-day virtual workshops, 20 professionals from diverse disciplines, professions, and countries discussed key developments and identified opportunities for future research, with additional input via online correspondence. Participants highlighted a "frailty rehabilitation paradox" whereby pulmonary rehabilitation can effectively reduce frailty, but programs are challenging for some individuals with frailty to complete. Frailty should not limit access to rehabilitation; instead, the identification of frailty should prompt comprehensive assessment and tailored support, including onward referral for additional specialist input. Exercise prescriptions that explicitly consider symptom burden and comorbidities, integration of additional geriatric or palliative care expertise, and/or preemptive planning for disruptions to participation may support engagement and outcomes. To identify and measure frailty in people with respiratory disease, tools should be selected on the basis of sensitivity, specificity, responsiveness, and feasibility for their intended purpose. Research is required to expand understanding beyond the physical dimensions of frailty and to explore the merits and limitations of telerehabilitation or home-based pulmonary rehabilitation for people with chronic respiratory disease and frailty.

Risk Factors of Readmission Within 90 Days for Chronic Obstructive Pulmonary Disease Patients with Frailty and Construction of an Early Warning Model

Objective

This study aimed to explore the risk factors for readmission within 90 d in Chronic Obstructive Pulmonary Disease (COPD) patients with frailty and construct a clinical warning model.

Methods

COPD patients with frailty hospitalized in the Department of Respiratory and Critical Care Medicine of Yixing Hospital, Affiliated to Jiangsu University, were retrospectively collected from January 1, 2020, to June 30, 2022. Patients were divided into readmission and control groups according to readmission within 90 d. The clinical data of the two groups were evaluated by univariate and multivariate logistic regression analyses to identify readmission risk factors within 90 d in COPD patients with frailty. Then, a risk quantitative early warning model was constructed. Finally, the model's prediction efficiency was evaluated, and external verification was carried out.

Results

The multivariate logistic regression analysis showed that BMI, number of hospitalizations in the past year ≥ 2, CCI, REFS, and 4MGS were independent risk factors for readmission within 90 d in COPD patients with frailty. The early warning model for these patients was established as follows: Logit (p) = -1.896 + (-0.166 × BMI) + (0.969 × number of hospitalizations in the past year ≥ 2) + (0.265 × CCI) + (0.405 × REFS) + (-3.209 × 4MGS), and presented an area under the ROC curve (AUC) of 0.744 [95% CI: 0.687-0.801]. The AUC of the external validation cohort was 0.737 (95% CI: 0.648-0.826), and the AUC of the LACE warning model was 0.657 (95% CI:0.552-0.762).

Conclusion

The BMI, number of hospitalizations in the past year ≥ 2, CCI, REFS, and 4MGS were independent risk factors for readmission within 90 d in COPD patients with frailty. The early warning model presented a moderate predictive value for assessing the risk of readmission within 90 d in these patients.

Effect of Long-Term Oxygen Therapy on Reducing Rehospitalization of Patients with Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

INTRODUCTION

The aim of this work is to evaluate whether the addition of home oxygen therapy (HOT) would reduce readmission in chronic obstructive pulmonary disease (COPD) patients.

METHODS

PubMed, ScopeMed, Cochrane, Scopus, and Google Scholar databases were searched. The search strategy used the following keywords "chronic obstructive pulmonary disease", the intervention "long-term oxygen therapy", and the outcome "readmission" combined with the AND operator. The Newcastle-Ottawa Scale and Jadad Scale were used for assessing the quality of cohort studies and clinical trials, respectively. A random-effects model was employed in this study after calculating the standard errors by 95% confidence intervals. The I2 statistic and Cochran's Q-test were used to measure heterogeneity. To address heterogeneity, subgroup analyses were carried out according to the length of LTOT, which was classified as "over 8 months" and "under 8 months".

RESULTS

Seven studies were included in the analysis. In the pooled analysis, the RR [CI95%, p value], heterogeneity criteria for readmission reduced by 1.542 [1.284-1.851, < 0.001], I² = 60%, and 1.693 [1.645-1.744, < 0.001], I² = 60% for patients with a length of LTOT treatment under and above 8 months, respectively. A sensitivity analysis was conducted by systematically omitting each study, and it showed no influential studies. Egger's test indicated no publication bias (p = 0.64).

CONCLUSIONS

Based on our results in this systematic review, long-tern oxygen therapy (LTOT) at home was associated with a significantly lower risk ratio of hospital readmission. However, the sample sizes in the studies necessitate larger RCTs to evaluate the effect of LTOT on readmission in COPD patients.

Association between inpatient palliative care encounter and 30-day all-cause readmissions after index hospitalization for chronic obstructive pulmonary disease

BACKGROUND

Studies exist on the association between inpatient Palliative Care Encounter (iPCE) and 30-day rehospitalization among cancer and several non-cancer conditions but limited in persons with Chronic Obstructive Pulmonary Disease (COPD).

OBJECTIVE

To assess the association between an iPCE with the risk of 30-day rehospitalization after an index hospitalization for COPD.

METHODS

We conducted a cross-sectional analysis of the Nationwide Readmissions Database (2010-2014). Index hospitalizations were defined as persons ≥ 18 years of age, discharge destinations of either Home/Routine, Home with Home Care, or a Facility, and an index hospitalization with Diagnosis Related Group of COPD. The International Classification of Diseases, 9th revision codes were used to extract comorbidities and a Palliative Care Encounter (V66.7).

RESULTS

There were 3,163,889 index hospitalizations and iPCE occurred in 21,330 (0.67%). There were 558,059 (17.63%) with a 30-day rehospitalization. An iPCE was associated with a significantly lower adjusted odds of 30-day readmission (Odds Ratio [OR], 0.50; 95% Confidence Interval [CI], 0.46 to 0.54).  By discharge destination, the odds of 30-day rehospitalization were for a discharged to a facility (OR, 0.37; 95% CI, 0.32 to 0.42), to home with home health (OR, 0.42; 95% CI, 0.37 to 0.47), and to home (OR, 0.98; 95% CI, 0.85 to 1.12) for those with relative to without iPCE.

CONCLUSION

Inpatient PCE was associated with a 50% lower relative odds of 30-day rehospitalization after an index hospitalization for COPD. This association varied by discharge destination being statistically significant among those with a discharge destination of a facility (63%) and home with home care (58%).

Selective androgen receptor modulation for muscle weakness in chronic obstructive pulmonary disease: a randomised control trial

BACKGROUND

Selective androgen receptor modulators (SARMs) increase muscle mass via the androgen receptor. This phase 2A trial investigated the effects of a SARM, GSK2881078, in conjunction with exercise, on leg strength in patients with chronic obstructive pulmonary disease (COPD) and impaired physical function.

METHODS

47 postmenopausal women and 50 men with COPD (forced expiratory volume in 1 s 30%-65% predicted; short physical performance battery score: 3-11) were enrolled into a randomised double-blind, placebo control trial. Patients were randomised 1:1 to once daily placebo or oral GSK2881078 (females: 1.0 mg; males: 2.0 mg) for 13 weeks with a concurrent home-exercise programme, involving strength training and physical activity. Primary endpoints were change from baseline in leg strength at 90 days (one-repetition maximum; absolute (kg) and relative (% change)) and multiple safety outcomes. Secondary endpoints included lean body mass, physical function and patient-reported outcomes.

RESULTS

GSK2881078 increased leg strength in men. The difference in adjusted mean change from baseline and adjusted mean percentage change from baseline between treatment and placebo were: for women, 8.0 kg (90% CI -2.5 to 18.4) and 5.2% (90% CI -4.7 to 15.0), respectively; for men, 11.8 kg (90% CI -0.5 to 24.0) and 7.0% (90% CI 0.5 to 13.6), respectively. Lean body mass increased, but no changes in patient-reported outcomes were observed. Reversible reductions in high-density lipoprotein-cholesterol and transient elevations in hepatic transaminases were the main treatment-related safety findings.

CONCLUSIONS

GSK2881078 was well tolerated and short-term treatment increased leg strength, when expressed as per cent predicted, in men with COPD more than physical training alone.

TRIAL REGISTRATION NUMBER

NCT03359473.

All-cause readmission rate and risk factors of 30- and 90-day after discharge in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

The readmission rate following hospitalization for chronic obstructive pulmonary disease (COPD) is surprisingly high, and frequent readmissions represent a higher risk of mortality and a heavy economic burden. However, information on all-cause readmissions in patients with COPD is limited.

OBJECTIVE

This study aimed to systematically summarize all-cause COPD readmission rates within 30 and 90 days after discharge and their underlying risk factors.

METHODS

Eight electronic databases were searched to identify relevant observational studies about COPD readmission from inception to 1 August 2022. Newcastle-Ottawa Scale was used for methodological quality assessment. We adopt a random effects model or a fixed effects model to estimate pooled all-cause COPD readmission rates and potential risk factors.

RESULTS

A total of 28 studies were included, of which 27 and 8 studies summarized 30- and 90-day all-cause readmissions, respectively. The pooled all-cause COPD readmission rates within 30 and 90 days were 18% and 31%, respectively. The World Health Organization region was initially considered to be the source of heterogeneity. We identified alcohol use, discharge destination, two or more hospitalizations in the previous year, and comorbidities such as heart failure, diabetes, chronic kidney disease, anemia, cancer, or tumor as potential risk factors for all-cause readmission, whereas female and obesity were protective factors.

CONCLUSIONS

Patients with COPD had a high all-cause readmission rate, and we also identified some potential risk factors. Therefore, it is urgent to strengthen early follow-up and targeted interventions, and adjust or avoid risk factors after discharge, so as to reduce the major health economic burden caused by frequent readmissions.

TRIAL REGISTRATION

This systematic review and meta-analysis protocol was prospectively registered with PROSPERO (no. CRD42022369894).

Exploiting Resistive Matrix Technology to Build a Stretchable Sensorised Sock for Gait Analysis in Daily Life

We describe the development and preliminary evaluation of an innovative low-cost wearable device for gait analysis. We have developed a sensorized sock equipped with 32 piezoresistive textile-based sensors integrated in the heel and metatarsal areas for the detection of signals associated with the contact pressures generated during walking phases. To build the sock, we applied a sensing patch on a commercially available sock. The sensing patch is a stretchable circuit based on the resistive matrix method, in which conductive stripes, based on conductive inks, are coupled with piezoresistive fabrics to form sensing elements. In our sensorized sock, we introduced many relevant improvements to overcome the limitations of the classical resistive matrix method. We preliminary evaluated the sensorized sock on five healthy subjects by performing a total of 80 walking tasks at different speeds for a known distance. Comparison of step count and step-to-step frequency versus reference measurements showed a high correlation between the estimated measure and the real one.

Reference Values for 7 Different Protocols of Simple Functional Tests: A Multicenter Study

OBJECTIVES

To establish reference values and equations (ages 20-80y) for 7 simple functional tests based on a multicenter study.

DESIGN

Cross-sectional data collection in 4 research centers across different regions of a continental dimension country.

SETTING

Healthy subjects from general community were assessed in different research laboratories.

PARTICIPANTS

Data collection of 296 volunteer subjects (N=296; 45% men; aged 50±18y, forced expiratory volume in the first second 95±13% pred, body mass index 26.9±4.5 kg/m²) aged 20-80 years; representing both sexes; with the ability to understand and perform all proposed assessments; and with no severe and/or unstable condition that could limit functional assessments occurred simultaneously in all centers.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

All participants randomly performed the following 7 functional tests twice: (1) the 4-meter gait speed test at usual walking speed; (2) the 4-meter gait speed test at maximal walking speed; (3) the Sit-to-Stand test performed with 5 repetitions; (4) the Sit-to-Stand test performed in 30 seconds; (5) the Sit-to-Stand test performed in 1 minute; (6) the Timed Up and Go test at usual speed; and (7) the Timed Up and Go test at maximal speed. Spirometry, quality of life, depression, anxiety, physical activity, and comorbidities were also assessed to better characterize the sample. The best performance of each test was used to propose reference values for men and women and reference equations for all.

RESULTS

Participants similarly distributed by age groups from the 4 centers were included. All tests were correlated with age (0.34<r<0.53) and body mass index (0.24<r< 0.31; P<.05 for all). Reference values with limits of normality were provided by each 10-year age group and regression models identified reference equations for all tests. Reliability of the reference equations were confirmed in an independent sample.

CONCLUSIONS

Reference values and equations for 7 widely used simple functional tests were provided in this study and might help researchers and clinicians to identify and quantify functional impairments using easy-to-perform assessments.

Gait speed is associated with death or readmission among patients surviving acute hypercapnic respiratory failure

Objectives

Death or hospital readmission are frequent among patients surviving acute hypercapnic respiratory failure (AHRF). Severity scores are not valid to predict death or readmission after AHRF. Gait speed, a simple functional parameter, has been associated with hospital admission and death in the general population. The purpose of this study is to highlight an association between gait speed at hospital discharge and death or readmission among AHRF survivors.

Design

Secondary analysis of a prospective cohort study.

Settings

Single Swiss tertiary hospital, pulmonary division.

Participants

Patients were prospectively recruited to form a cohort of patients surviving AHRF in the intensive care unit between January 2012 and May 2015.

Outcome measure

Gait speed was derived from a 6 min walking test (6MWT) before hospital discharge. All predictive variables were prospectively collected. Death or hospital readmission were recorded for 6 months. Univariate and multivariate analyses were performed to evaluate the association between predictive variables and death or hospital readmission.

Results

71 patients performed a 6MWT. 34/71 (48%) patients died or were readmitted to the hospital during the observation period. Median gait speed was 0.7 (IQR 0.3–1.0) m/s. At 6 months, 66% (25/38) of slow walkers (gait speed <0.7 m/s) and 27% (9/33) of non-slow walkers died or were readmitted to the hospital (p=0.002). In univariate analysis, gait speed was associated with death or readmission (HR 0.41; 95% CI 0.19 to 0.90, p=0.025). In a multivariate model adjusted for age, gender, body mass index, forced expired volume, heart failure and home mechanical ventilation, gait speed remained the only variable associated with death or readmission (multivariate HR: 0.35; 95% CI 0.14 to 0.88, p=0.025).

Conclusion

This study suggests that a simple functional parameter such as gait speed is associated with death or hospital readmission in patients surviving AHRF.

Trial registration number

NCT02111876.

Frailty and aging-associated syndromes in lung transplant candidates and recipients

Many lung transplant candidates and recipients are older and frailer compared to previous eras. Older patients are at increased risk for pre- and posttransplant mortality, but this risk is not explained by numerical age alone. This manuscript represents the product of the American Society of Transplantation (AST) conference on frailty. Experts in the field reviewed the latest published research on assessment of elderly and frail lung transplant candidates. Physical frailty, often defined as slowness, weakness, low physical activity, shrinking, and exhaustion, and frailty evaluation is an important tool for evaluation of age-associated dysfunction. Another approach is assessment by cumulative deficits, and both types of frailty are common in lung transplant candidates. Frailty is associated with death or delisting before transplant, and may be associated with posttransplant mortality. Sarcopenia, cognitive dysfunction, depression, and nutrition are other important components for patient evaluation. Aging-associated inflammation, telomere dysfunction, and adaptive immune system senescence may also contribute to frailty. Developing tools for frailty assessment and interventions holds promise for improving patient outcomes before and after lung transplantation.

Gait speed and adverse outcomes following hospitalised exacerbation of COPD

Four-metre gait speed (4MGS) is a simple physical performance measure and surrogate marker of frailty that is associated with adverse outcomes in older adults. We aimed to assess the ability of 4MGS to predict prognosis in patients hospitalised with acute exacerbations of COPD (AECOPD).213 participants hospitalised with AECOPD (52% male, mean age and FEV₁, 72 years and 35% predicted) were enrolled. 4MGS and baseline demographics were recorded at hospital discharge. All-cause readmission and mortality were collected for 1 y after discharge, and multivariable Cox-proportional hazards regression were performed. Kaplan-Meier and Competing risk analysis was conducted comparing time to all-cause readmission and mortality between 4MGS quartiles.111 participants (52%) were readmitted, and 35 (16%) died during the follow-up period. 4MGS was associated with all-cause readmission, with an adjusted subdistribution hazard ratio of 0.868 (95% CI 0.797-0.945; p=0.001) per 0.1 m·s^-1 increase in gait speed, and with all-cause mortality with an adjusted subdistribution hazard ratio of 0.747 (95% CI: 0.622-0.898; p=0.002) per 0.1 m·s^-1 increase in gait speed. Readmission and mortality models incorporating 4MGS had higher discrimination than age or FEV₁% predicted alone, with areas under the receiver operator characteristic curves of 0.73 and 0.80 respectively. Kaplan-Meier and Competing Risk curves demonstrated that those in slower gait speed quartiles had reduced time to readmission and mortality (log rank both p<0.001).4MGS provides a simple means of identifying at-risk patients with COPD at hospital discharge. This provides valuable information to plan post-discharge care and support.

Correlation of 4-meter gait speed with clinical indicators of chronic obstructive pulmonary disease

BACKGROUND

Measuring daily physical activity and exercise capacity is recommended in the routine care of patients with chronic obstructive pulmonary disease (COPD). The 4-m gait speed (4mGS) is simple and effective in stratifying patients according to exercise performance, dyspnea, health status, and prognosis. We assessed the reliability of the 4mGS as a clinical marker by examining its association with established clinical indicators among hospitalized patients with COPD.

METHODS

This retrospective study included 78 patients hospitalized with COPD (mean age: 76.3 ± 0.9 years; males, n = 69) between January 2016 and June 2018 who were assessed using the 4mGS and divided into slow (<0.8 m/s) and normal (≥0.8 m/s) 4mGS groups. Clinical characteristics were compared, including death during the observation period, time to first exacerbation, and long-term oxygen therapy requirement.

RESULTS

There were strong relationships between 4mGS performance, the 6-min walk test (R = 0.70; p < 0.0001), and the modified Medical Research Council dyspnea scale (R = 0.68; p < 0.0001) among the 78 patients. The slow 4mGS group had a higher frequency of death during the observation period (p = 0.0095) and a greater requirement for long-term oxygen therapy (p = 0.0063). The 4mGS correlated with inspiratory capacity (IC) and IC/total lung capacity ratios, which are respiratory failure indicators.

CONCLUSIONS

The 4mGS is a simple and easy method of assessing the physical condition as well as estimating the prognosis of patients with COPD, and may serve as a useful marker in home medical treatment or clinical settings.

[Which physical tests for which objectives in pulmonary rehabilitation?]

Chronic respiratory disease is a major cause of morbidity and mortality worldwide and an important cause of disability including a reduction of exercise, functional and muscle capacity contributing to a decreased quality of life. In the context of pulmonary rehabilitation, a thorough patient-centered outcome assessment, including not only measures of lung function, but also exercise functional and muscle capacity, is imperative for a comprehensive disease management. Assessment of these impairments and dysfunctions with appropriate and change-sensitive procedures is thus necessary for personalizing the physical interventions and assessing the short- and long-term effectiveness of the intervention. The clinician currently has a wide variety of tests and measurements available to assess the physical and functional capacity of people with chronic respiratory disease. The aim of this review is to provide a pragmatic synthesis of the physical, functional and muscle capacity tests most commonly used in pulmonary rehabilitation. Ultimately, it should help the clinician to identify the relevant evaluations according to the objectives of the patients but also according to the available resources, the setting of pulmonary rehabilitation and the specific qualities of each test.

Weak Handgrip at Index Admission for Acute Exacerbation of COPD Predicts All-Cause 30-Day Readmission

Rationale: Identifying patients hospitalized for acute exacerbations of COPD (AECOPD) who are at high risk for readmission is challenging. Traditional markers of disease severity such as pulmonary function have limited utility in predicting readmission. Handgrip strength, a component of the physical frailty phenotype, may be a simple tool to help predict readmission. Objective(s): To investigate if handgrip strength, a component of the physical frailty phenotype and surrogate for weakness, is a predictive biomarker of COPD readmission. Methods: This was a prospective, observational study of patients admitted to the inpatient general medicine unit at the University of Chicago Medicine, US. This study evaluated age, sex, ethnicity, degree of obstructive lung disease by spirometry (FEV1 percent predicted), and physical frailty phenotype (components include handgrip strength and walk speed). The primary outcome was all-cause hospital readmission within 30 days of discharge. Results: Of 381 eligible patients with AECOPD, 70 participants agreed to consent to participate in this study. Twelve participants (17%) were readmitted within 30 days of discharge. Weak grip at index hospitalization, defined as grip strength lower than previously established cut-points for sex and body mass index (BMI), was predictive of readmission (OR 11.2, 95% CI 1.3, 93.2, p = 0.03). Degree of airway obstruction (FEV1 percent predicted) did not predict readmission (OR 1.0, 95% CI 0.95, 1.1, p = 0.7). No non-frail patients were readmitted. Conclusions: At a single academic center weak grip strength was associated with increased 30-day readmission. Future studies should investigate whether geriatric measures can help risk-stratify patients for likelihood of readmission after admission for AECOPD.

The five-repetition sit-to-stand test is a predictive factor of severe exacerbations in COPD

BACKGROUND

Although the six-minute-walk test (6MWT) has been used to predict chronic obstructive pulmonary disease (COPD) exacerbations, additional research is necessary to identify more rapid, simpler tests that are directly associated with exacerbations, such as the five-repetition sit-to-stand (5STS) test and 4-m gait speed (4MGS) test.

AIMS

To determine the ability of the 5STS and 4MGS tests in predicting severe exacerbations in stable COPD over the following year, and to assess the ability of the best prognostic test to identify patients at high risk of hospital admission correctly.

METHODS

This prospective study included 137 patients with stable COPD. Multiple logistic regression models were constructed to assess whether the 6MWT, 5STS, and 4MGS tests were associated with severe exacerbations in the year following the test. Receiver-operating characteristic curves and the area under the curve (AUC) were evaluated to determine the accuracy of each test for identifying patients with severe exacerbations.

RESULTS

Scores of <350 m for the 6WMT and ⩽2 for the 5STS test were associated with severe exacerbations in the model adjusted for age and the number of exacerbations in the previous year. The 5STS test and the 6MWT had very similar predictive and discriminative abilities. Odds ratios were 3.20 (95% confidence interval [CI] 1.14-8.96) and 3.84 (95% CI 1.14-12.94) and AUCs were 0.793 (95% CI 0.704-0.882) and 0.783 (95% CI 0.686-0.879), respectively.

CONCLUSIONS

The 5STS test predicted the risk of severe exacerbation within the following year among patients with COPD. The 5STS test could replace the 6MWT for identifying patients at high risk of hospital admission.

COPD in the time of COVID-19: an analysis of acute exacerbations and reported behavioural changes in patients with COPD

INTRODUCTION

The impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and associated "lockdown" measures on acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is unknown. We aimed to evaluate the change in AECOPD treatment frequency during the first 6 weeks of lockdown in the UK compared with 2019 and assess changes in self-reported behaviour and wellbeing.

METHODS

In this observational study in Leicestershire, UK, patients with COPD under a secondary care clinic were recruited. Exacerbation frequency in the first 6 weeks of COVID-19 lockdown was compared with the same period in 2019 using electronic health records. A telephone survey was used to assess changes in anxiety, inhaler adherence, physical activity and behaviour during the pre-lockdown and lockdown periods compared with normal.

RESULTS

160 participants were recruited (mean±sd age 67.3±8.1 years, 88 (55%) males, mean±sd forced expiratory volume in 1 s 34±13% pred). 140 (88%) reported at least one AECOPD in the previous year. Significantly more community managed exacerbations were observed in 2020 compared with 2019 (126 versus 99; p=0.026). The increase was a result of multiple courses of treatment, with a similar proportion of patients receiving at least one course (34.4% versus 33.8%).

DISCUSSION

During lockdown participants reported significantly increased anxiety, adherence to their preventative inhalers and good adherence to shielding advice (all p<0.001). A significant reduction in self-reported physical activity and visitors was reported (both p<0.001).

CONCLUSIONS

Treatment for AECOPD events increased during the first 6 weeks of the SARS-CoV-2 pandemic in the UK compared with 2019. This was associated with increased symptoms of anxiety and significant behavioural change.

The Effects of a Video Intervention on Posthospitalization Pulmonary Rehabilitation Uptake. A Randomized Controlled Trial

Rationale: Pulmonary rehabilitation (PR) after hospitalizations for exacerbations of chronic obstructive pulmonary disease (COPD) improves exercise capacity and health-related quality of life and reduces readmissions. However, posthospitalization PR uptake is low. To date, no trials of interventions to increase uptake have been conducted.Objectives: To study the effect of a codesigned education video as an adjunct to usual care on posthospitalization PR uptake.Methods: The present study was an assessor- and statistician-blinded randomized controlled trial with nested, qualitative interviews of participants in the intervention group. Participants hospitalized with COPD exacerbations were assigned 1:1 to receive either usual care (COPD discharge bundle including PR information leaflet) or usual care plus the codesigned education video delivered via a handheld tablet device at discharge. Randomization used minimization to balance age, sex, FEV₁ % predicted, frailty, transport availability, and previous PR experience.Measurements and Main Results: The primary outcome was PR uptake within 28 days of hospital discharge. A total of 200 patients were recruited, and 196 were randomized (51% female, median FEV_1% predicted, 36 [interquartile range, 27-48]). PR uptake was 41% and 34% in the usual care and intervention groups, respectively (P = 0.37), with no differences in secondary (PR referral and completion) or safety (readmissions and death) endpoints. A total of 6 of the 15 participants interviewed could not recall receiving the video.Conclusions: A codesigned education video delivered at hospital discharge did not improve posthospitalization PR uptake, referral, or completion.

Experimental dyspnoea interferes with locomotion and cognition: a randomised trial

BACKGROUND

Chronic respiratory diseases are associated with cognitive dysfunction, but whether dyspnoea by itself negatively impacts on cognition has not been demonstrated. Cortical networks engaged in subjects experiencing dyspnoea are also activated during other tasks that require cognitive input and this may provoke a negative impact through interference with each other.

METHODS

This randomised, crossover trial investigated whether experimentally-induced dyspnoea would negatively impact on locomotion and cognitive function among 40 healthy adults. Crossover conditions were unloaded breathing or loaded breathing using an inspiratory threshold load. To evaluate locomotion, participants were assessed by the Timed Up and Go (TUG) test. Cognitive function was assessed by categorical and phonemic verbal fluency tests, the Trail Making Tests (TMTs) A and B (executive function), the CODE test from the Wechsler Adult Intelligence Scale (WAIS)-IV (processing speed) and by direct and indirect digit span (working memory).

RESULTS

The mean time difference to perform the TUG test between unloaded and loaded breathing was -0.752 s (95% CI -1.012 to -0.492 s) (p<0.001). Executive function, processing speed and working memory performed better during unloaded breathing, particularly for subjects starting first with the loaded breathing condition.

CONCLUSION

Our data suggest that respiratory threshold loading to elicit dyspnoea had a major impact on locomotion and cognitive function in healthy adults.

Risk factors for all-cause hospital readmission following exacerbation of COPD: a systematic review and meta-analysis

BACKGROUND

Readmission rates following hospitalisation for COPD exacerbations are unacceptably high, and the contributing factors are poorly understood. Our objective was to summarise and evaluate the factors associated with 30- and 90-day all-cause readmission following hospitalisation for an exacerbation of COPD.

METHODS

We systematically searched electronic databases from inception to 5 November 2019. Data were extracted by two independent authors in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Study quality was assessed using a modified version of the Newcastle-Ottawa Scale. We synthesised a narrative from eligible studies and conducted a meta-analysis where this was possible using a random-effects model.

RESULTS

In total, 3533 abstracts were screened and 208 full-text manuscripts were reviewed. A total of 32 papers met the inclusion criteria, and 14 studies were included in the meta-analysis. The readmission rate ranged from 8.8-26.0% at 30 days and from 17.5-39.0% at 90 days. Our narrative synthesis showed that comorbidities, previous exacerbations and hospitalisations, and increased length of initial hospital stay were the major risk factors for readmission at 30 and 90 days. Pooled adjusted odds ratios (95% confidence intervals) revealed that heart failure (1.29 (1.22-1.37)), renal failure (1.26 (1.19-1.33)), depression (1.19 (1.05-1.34)) and alcohol use (1.11 (1.07-1.16)) were all associated with an increased risk of 30-day all-cause readmission, whereas being female was a protective factor (0.91 (0.88-0.94)).

CONCLUSIONS

Comorbidities, previous exacerbations and hospitalisation, and increased length of stay were significant risk factors for 30- and 90-day all-cause readmission after an index hospitalisation with an exacerbation of COPD.

Gait Speed at Discharge and Risk for Readmission or Death: A Prospective Study of an Emergency Ward Population

Background

There has been a growing interest in measuring gait speed for assessing long-term mortality and risk for hospital readmission in different populations.

Objective

We studied the association between a 10-meter gait speed test at hospital discharge and the risk for 30- and 90-day hospital readmission or death in a mixed population of patients hospitalized for emergency care.

Patients and Methods

Patients were prospectively included from 5 wards at the Karolinska University Hospital. The 10-meter gait speed test was measured on the day of discharge. Statistical analysis was performed using logistic regression.

Results

A total of 344 patients were included. Forty-one patients (n=41) were readmitted to hospital or died within 30 days, and 81 were readmitted or died within 90 days after discharge. Readmitted patients were older and had more comorbidities. A 0.1 m/s reduction in gait speed was associated with a 13% greater odds of readmission or death within 30 days (OR 1.13 [95% CI 1.00–1.26]). The area under the receiver operating characteristic curve (AUC) was 0.59 (95% CI 0.51–0.68). The results were similar for 90-day readmission or death where a 0.1 m/s decrement in gait speed was associated with an OR of 1.13 (95% CI 1.04–1.24). When age, eGFR, hemoglobin concentration, and active cancer, which all were univariate predictors of 30-day readmissions, were added to the model it yielded an AUC of 0.68 (95% CI 0.60 to 0.77).

Conclusion

In a mixed population of patients hospitalized for emergency care, low gait speed at discharge was associated with an increased risk of 30- and 90-day readmission or death. However, the test did not discriminate well between those who were readmitted or died and those who did not; therefore we do not recommend its use as a stand-alone test in this population.

Improving Exercise-Based Interventions for People Living with Both COPD and Frailty: A Realist Review

Background

People living with both chronic obstructive pulmonary disease (COPD) and frailty have high potential to benefit from exercise-based interventions, including pulmonary rehabilitation, but face challenges completing them. Research to understand ways to optimise exercise-based interventions in this group is lacking. We aimed to understand how exercise-based interventions might improve outcomes for people living with both COPD and frailty.

Methods

This realist review used database searches and handsearching until October 2019 to identify articles of relevance to exercise-based interventions for people living with COPD and frailty. A scoping search explored what is important about the context of living with COPD and frailty, and what mechanisms might be important in how exercise-based interventions result in their intended outcomes. Through discussion with stakeholders, the review scope was refined to areas deemed pertinent to improving care. We retained articles within this refined scope and identified additional articles through targeted handsearching. Data were extracted and synthesised in a narrative, prioritised by relevance and rigour.

Results

Of 344 records identified, 35 were included in the review and 20 informed the final synthesis. Important contextual factors to consider included: negative beliefs about themselves and exercise-based interventions; heterogenous presentation and comorbidities; decreased reserves and multidimensional loss; and experiencing unpredictable health and disruptions. In these circumstances, mechanisms that may help maximise outcomes from exercise-based interventions included: trusting relationships; creating a shared understanding of needs; having the capacity to address multidimensional concerns; being able to individualise approaches to needs and priorities; and flexible approaches to intervention delivery. Mixed-methods research and explicit theorising were often absent.

Conclusion

Building trusting relationships, understanding priorities, using individualised and multidisciplinary approaches, and flexible service delivery can improve the value of exercise-based interventions for people living with both COPD and frailty. Development and evaluation of new and adapted interventions should consider these principles.

Predicting and preventing hospital readmission for exacerbations of COPD

More than a third of patients hospitalised for acute exacerbation of COPD are readmitted to hospital within 90 days. Healthcare professionals and service providers are expected to collaboratively drive efforts to improve hospital readmission rates, which can be challenging due to the lack of clear consensus and guidelines on how best to predict and prevent readmissions. This review identifies these risk factors, highlighting the contribution of multimorbidity, frailty and poor socioeconomic status. Predictive models of readmission that address the multifactorial nature of readmissions and heterogeneity of the disease are reviewed, recognising that in an era of precision medicine, in-depth understanding of the intricate biological mechanisms that heighten the risk of COPD exacerbation and re-exacerbation is needed to derive modifiable biomarkers that can stratify accurately the highest risk groups for targeted treatment. We evaluate conventional and emerging strategies to reduce these potentially preventable readmissions. Here, early recognition of exacerbation symptoms and the delivery of prompt treatment can reduce risk of hospital admissions, while patient education can improve treatment adherence as a key component of self-management strategies. Care bundles are recommended to ensure high-quality care is provided consistently, but evidence for their benefit is limited to date. The search continues for interventions which are effective, sustainable and applicable to a diverse population of patients with COPD exacerbations. Further research into mechanisms that drive exacerbation and affect recovery is crucial to improve our understanding of this complex, highly prevalent disease and to advance the development of more effective treatments.

The validity and reliability of four-meter gait speed test for stable interstitial lung disease patients: the prospective study

Background

The 4-m gait speed test is a simple functional performance measure for older adults or patients with chronic obstructive lung disease. However, limited data exist regarding these measures for patients with interstitial lung disease. We evaluated the correlation between the 4-m gait speed and 6-min walk distance tests for interstitial lung disease patients and examined their underlying physiological factors.

Methods

The 4-m gait speed and 6-min walk tests were prospectively conducted for 51 patients with interstitial lung disease. Other measurements included health-related quality of life, modified Medical Research Council score, arterial blood gas levels, pulmonary function, muscle strength according to the skeletal muscle mass index and physical activity.

Results

Thirty-five patients were male (68.6%). Thirty-four patients had idiopathic pulmonary fibrosis (66.7%). There were significant correlations between the 4-m gait speeds and 6-min walk distances (r=0.57; P<0.001). Multivariate analyses showed that both the 4-m gait speed and 6-min walk distance were correlated with the modified Medical Research Council score. In addition, the 6-min walk distance was correlated with age and the percentage of the predicted diffusion capacity of carbon monoxide.

Conclusions

The 4-m gait speed test is a simple, easy to perform and reliable functional performance measure for interstitial lung disease patients.

Risk assessment for hospital admission in patients with COPD; a multi-centre UK prospective observational study

In chronic obstructive pulmonary disease (COPD), acute exacerbation of COPD requiring hospital admission is associated with mortality and healthcare costs. The ERICA study assessed multiple clinical measures in people with COPD, including the short physical performance battery (SPPB), a simple test of physical function with 3 components (gait speed, balance and sit-to-stand). We tested the hypothesis that SPPB score would relate to risk of hospital admissions and length of hospital stay. Data were analysed from 714 of the total 729 participants (434 men and 280 women) with COPD. Data from this prospective observational longitudinal study were obtained from 4 secondary and 1 tertiary centres from England, Scotland, and Wales. The main outcome measures were to estimate the risk of hospitalisation with acute exacerbation of COPD (AECOPD and length of hospital stay derived from hospital episode statistics (HES). In total, 291 of 714 individuals experienced 762 hospitalised AECOPD during five-year follow up. Poorer performance of SPPB was associated with both higher rate (IRR 1.08 per 1 point decrease, 95% CI 1.01 to 1.14) and increased length of stay (IRR 1.18 per 1 point decrease, 95% CI 1.10 to 1.27) for hospitalised AECOPD. For the individual sit-to-stand component of the SPPB, the association was even stronger (IRR 1.14, 95% CI 1.02 to 1.26 for rate and IRR 1.32, 95% CI 1.16 to 1.49 for length of stay for hospitalised AECOPD). The SPPB, and in particular the sit-to-stand component can both evaluate the risk of H-AECOPD and length of hospital stay in COPD. The SPPB can aid in clinical decision making and when prioritising healthcare resources.

Gait Measurement at Home Using A Single RGB Camera

BACKGROUND

An individual's gait is a key factor for consideration in evaluating their overall health. Several medical studies have demonstrated the correlation between gait and incidence rate of diseases, mortality, and risk of fall. However, gait is only occasionally evaluated during medical visits, which may delay the detection of health problems.

METHODS

In this paper, we propose a gait measurement system that is suitable for use at home. Our method requires only a single RGB camera, whereas other visionary sensor-based methods require depth sensors or multiple RGB cameras. In addition, the setup for the measurement is easy. What the user has to do is only putting a single camera in a room and choosing four location known points on the floor. Our method can measure step positions and step timings, and therefore, other important parameters such as stride length, step width, walking speed, and cadence may also be captured. The individual's gait is captured by the camera, and therefore the user is not required to wear any devices.

RESULTS

In the experiment described herein, we demonstrate our method's accuracy by comparing it with the motion capture system. The results indicate that our method can measure walking speed with an error of 3.62 cm/s from the side view, and which is too small a change to be clinically meaningful.

Short Physical Performance Battery: What Does Each Sub-Test Measure in Patients with Chronic Obstructive Pulmonary Disease?

Objective

To identify phenotypic factors associated with the Short Physical Performance Battery (SPPB) and its individual sub-tests: standing balance, 4‑meter gait speed (4mGS) and 5-repetition sit-to-stand (5STS).

Methods

The Evaluation of the Role of Inflammation in non-pulmonary disease manifestations in Chronic Airways disease (ERICA) study recruited adult participants with stable chronic obstructive pulmonary disease (COPD). Proportional odds models identified factors associated with the SPPB, and a principal component analysis (PCA) evaluated how much SPPB variance was explainable by each of its 3 sub-tests.

Results

Of 729 enrolled participants, 717 (60% male, mean age 67 years) had full SPPB data. Overall, 76% of patients had some evidence of functional limitations (SPPB total score < 12). Scores < 4 were observed in 71%, 31%, and 22% of participants for the 5STS, 4mGS, and balance sub-tests, respectively. A longer 6-minute walk test and greater quadriceps maximal voluntary contraction decreased the odds of being in a lower score category for SPPB total score and for all 3 sub-tests. Aging, self-reported hypertension and higher dyspnea increased the odds, and being married decreased the odds of being in a lower category for total score. All sub-tests contributed equally to total score.

Conclusion

Each of the 3 sub-tests contributed independent information to the SPPB, demonstrating their usefulness for assessing COPD when considered together rather than individually. The 5STS sub-test had the greatest variation in scores and may thus have the best discriminatory power for clinical COPD studies of lower limb performance where only one SPPB test is feasible.

Is it possible to reverse frailty in patients with chronic obstructive pulmonary disease?

In recent years, frailty has attracted increasing attention from clinicians and health care workers. The influence of frailty on the elderly, especially those with chronic diseases of the respiratory system, is highly significant. Frailty is particularly more common in patients with chronic obstructive pulmonary disease (COPD). Frailty and COPD share many risk factors and pathophysiological mechanisms. As a comprehensive interventional method for chronic respiratory diseases, pulmonary rehabilitation is an important basic measure for the management of patients with COPD. Frailty in these patients can be reversed using pulmonary rehabilitation by targeting five components of the frailty phenotype at the entry point. The present review discusses the benefits of pulmonary rehabilitation in patients with COPD complicated by frailty and provides a theoretical basis for pulmonary rehabilitation treatment in this population. In addition, the timing of pulmonary rehabilitation is also addressed, with the prefrail stage being the "golden" period. The implementation of pulmonary rehabilitation must vary among individuals, and individualized treatment strategies will help maximize benefits.

Deterioration of Limb Muscle Function during Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Important features of both stable and acute exacerbation of chronic obstructive pulmonary disease (COPD) are skeletal muscle weakness and wasting. Limb muscle dysfunction during an exacerbation has been linked to various adverse outcomes, including prolonged hospitalization, readmission, and mortality. The contributing factors leading to muscle dysfunction are similar to those seen in stable COPD: disuse, nutrition/energy balance, hypercapnia, hypoxemia, electrolyte derangements, inflammation, and drugs (i.e., glucocorticoids). These factors may be the trigger for a downstream cascade of local inflammatory changes, pathway process alterations, and structural degradation. Ultimately, the clinical effects can be wide ranging and include reduced limb muscle strength. Current therapies, such as pulmonary/physical rehabilitation, have limited impact because of low participation rates. Recently, novel drugs have been developed in similar disorders, and learnings from these studies can be used as a foundation to facilitate discovery in patients hospitalized with a COPD exacerbation. Nevertheless, investigators should approach this patient population with knowledge of the limitations of each intervention. In this Concise Clinical Review, we provide an overview of acute muscle dysfunction in patients hospitalized with acute exacerbation of COPD and a strategic approach to drug development in this setting.

Four-meter gait speed predicts daily physical activity in patients with chronic respiratory diseases

BACKGROUND

Physical activity measures are valuable for assessing the progression of chronic respiratory diseases. The 4-m gait speed (4MGS) test is an established functional assessment in the elderly. However, the relationship between the 4MGS and daily activity in patients with chronic respiratory diseases has not been fully understood. The present study aimed to investigate whether the 4MGS predicted daily activity, including physical activity level (PAL), in patients with chronic respiratory diseases.

METHODS

We enrolled 57 patients with chronic respiratory diseases, including interstitial lung disease and chronic obstructive pulmonary disease, and evaluated the correlations between the 4MGS and various clinical parameters, including respiratory function, the 6-min walk test (6MWT), and daily activities, by using an accelerometer. Linear regression analysis was performed to identify significant predictors of daily activity.

RESULTS

The 4MGS was significantly correlated with daily step counts and PAL, as well as the 6 min walk distance (r = 0.477, p < 0.001; r = 0.433, p = 0.001; and r = 0.593, p < 0.001, respectively). In the multivariate linear regression analysis, the 4MGS, % predicted forced expiratory volume in 1 s, and body mass index were independent predictors of PAL. Receiver operating characteristic analysis revealed that a 4MGS <1.07 m/s was the optimal cutoff for predicting an inactive PAL (area under the curve, 0.728; 95% confidence interval, 0.589-0.866). Patients with a slower 4MGS had significantly reduced daily activity than did those with a preserved 4MGS, despite similar modified Medical Research Council dyspnea scale measures and respiratory parameters, such as oxygenation profiles.

CONCLUSIONS

The 4MGS test is a simple screening test and a useful predictor of worsening daily activity in patients with chronic respiratory diseases.

The use of wearable technology to monitor physical activity in patients with COPD: a literature review

Background: Physical activity is an important predictor for survival in patients with COPD. Wearable technology, such as pedometer or accelerometer, may offer an opportunity to quantify physical activity and evaluate related health benefits in these patients.

Objectives: To assess the performance of wearable technology in monitoring and improving physical activity in COPD patients from published studies.

Methods: Literature search of Medline, Cochrane, Dare, Embase and PubMed databases was made to find relevant articles that used wearable technology to monitor physical activity in COPD patients.

Results: We identified 13 studies that used wearable technology, a pedometer or an accelerator, to monitor physical activity in COPD patients. Of these, six studies were randomized controlled trials (RCTs) which used the monitors as part of the intervention. Two studies reported the same outcomes and comparable units. They had measured the difference that the intervention makes on the number of steps taken daily by the patients. The results were highly heterogeneous with I²=92%. The random-effects model gave an effect outcome on the number of steps taken daily of 1,821.01 [−282.71; 3,924.74] in favor of the wearable technology. Four of the 13 studies have reported technical issues with the use of the wearable technology, including high signal-to-noise ratio, memory storage problems and inaccuracy of counts. While other studies did not mention any technical issues, it is not clear whether these did not experience them or chose not to report them.

Conclusions: Our literature search has shown that data on the use of wearable technology to monitor physical activity in COPD patients are limited by the small number of studies and their heterogeneous study design. Further research and better-designed RCTs are needed to provide reliable results before physical activity monitors can be implemented routinely for COPD patients.

Biomarkers and clinical outcomes in COPD: a systematic review and meta-analysis

BACKGROUND

Conventional measures to evaluate COPD may fail to capture systemic problems, particularly musculoskeletal weakness and cardiovascular disease. Identifying these manifestations and assessing their association with clinical outcomes (ie, mortality, exacerbation and COPD hospital admission) is of increasing clinical importance.

OBJECTIVE

To assess associations between 6 min walk distance (6MWD), heart rate, fibrinogen, C reactive protein (CRP), white cell count (WCC), interleukins 6 and 8 (IL-6 and IL-8), tumour necrosis factor-alpha, quadriceps maximum voluntary contraction, sniff nasal inspiratory pressure, short physical performance battery, pulse wave velocity, carotid intima-media thickness and augmentation index and clinical outcomes in patients with stable COPD.

METHODS

We systematically searched electronic databases (August 2018) and identified 61 studies, which were synthesised, including meta-analyses to estimate pooled HRs, following Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Shorter 6MWD and elevated heart rate, fibrinogen, CRP and WCC were associated with higher risk of mortality. Pooled HRs were 0.80 (95% CI 0.73 to 0.89) per 50 m longer 6MWD, 1.10 (95% CI 1.02 to 1.18) per 10 bpm higher heart rate, 3.13 (95% CI 2.14 to 4.57) per twofold increase in fibrinogen, 1.17 (95% CI 1.06 to 1.28) per twofold increase in CRP and 2.07 (95% CI 1.29 to 3.31) per twofold increase in WCC. Shorter 6MWD and elevated fibrinogen and CRP were associated with exacerbation, and shorter 6MWD, higher heart rate, CRP and IL-6 were associated with hospitalisation. Few studies examined associations with musculoskeletal measures.

CONCLUSION

Findings suggest 6MWD, heart rate, CRP, fibrinogen and WCC are associated with clinical outcomes in patients with stable COPD. Use of musculoskeletal measures to assess outcomes in patients with COPD requires further investigation.

TRIAL REGISTRATION NUMBER

CRD42016052075.

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.

Rehabilitation in chronic respiratory diseases: In-hospital and post-exacerbation pulmonary rehabilitation

Exacerbations of chronic obstructive pulmonary disease (COPD) that require hospitalization are important events for patients. Functional impairment and skeletal muscle dysfunction can increase the risk of hospitalization and readmission, independent of lung function. In addition, once a patient is admitted, multiple factors can lead to worsening outcome including immobility, systemic inflammation and nutritional depletion. These non-pulmonary factors are potentially amenable to exercise therapy, as part of pulmonary rehabilitation (PR). Peri-exacerbation PR has an important role in the management of exacerbations of COPD. In this review, we explore how functional limitation and skeletal muscle dysfunction affect patients having a severe exacerbation of COPD, the systemic impact of hospitalization on patients including potential aetiologies and the role of PR around the time of an exacerbation. This includes rehabilitation during the inpatient phase, post-exacerbation rehabilitation and rehabilitation bridging hospital discharge. We also describe potential future developments in peri-exacerbation PR.

Gait speed and prognosis in patients with idiopathic pulmonary fibrosis: a prospective cohort study

The 4-m gait speed (4MGS), a simple physical performance measure and surrogate marker of frailty, consistently predicts adverse prognosis in older adults. We hypothesised that 4MGS could predict all-cause mortality and nonelective hospitalisation in patients with idiopathic pulmonary fibrosis (IPF).4MGS and lung function were measured at baseline in 130 outpatients newly diagnosed with IPF. Survival status and nonelective hospital admissions were recorded over 1 year. We assessed the predictive value of 4MGS (as a continuous variable and as a binary variable: slow versus preserved 4MGS) by calculating hazard ratios using Cox proportional regression, adjusting for potential confounding variables. Receiver operating characteristic curves assessed discrimination between the multivariable regression models and established prognostic indices.Continuous 4MGS and slow 4MGS were independent predictors of all-cause mortality (4MGS: HR 0.03, 95% CI 0.01-0.31; p=0.004; slow 4MGS: 2.63, 95% CI 1.01-6.87; p=0.049) and hospitalisation (4MGS: HR 0.02, 95% CI 0.01-0.14; p<0.001; slow 4MGS: 2.76, 95% CI 1.16-6.58; p=0.02). Multivariable models incorporating 4MGS or slow 4MGS had better discrimination for predicting mortality than either the gender, age and lung physiology index or Composite Physiologic Index.In patients with IPF, 4MGS is an independent predictor of all-cause mortality and nonelective hospitalisation.

Predictive factors for exacerbation and re-exacerbation in chronic obstructive pulmonary disease: an extension of the Cox model to analyze data from the Swiss COPD cohort

Background

The Swiss COPD cohort was established in 2006 to collect data in a primary care setting. The objective of this study was to evaluate possible predictive factors for exacerbation and re-exacerbation.

Methods

In order to predict exacerbation until the next visit based on the knowledge of exacerbation since the last visit, a multistate model described by Therneau and Grambsch was performed.

Results

Data of 1,247 patients (60.4% males, 46.6% current smokers) were analyzed, 268 (21.5%) did not fulfill spirometric diagnostic criteria for COPD. Data of 748 patients (63% males, 44.1% current smokers) were available for model analysis. In order to predict exacerbation an extended Cox Model was performed. Mean FEV₁/FVC-ratio was 53.1% (±11.5), with a majority of patients in COPD GOLD classes 2 or 3. Hospitalization for any reason (HR1.7; P = 0.04) and pronounced dyspnea (HR for mMRC grade four 3.0; P < 0.001) at most recent visit as well as prescription of short-acting bronchodilators (HR1.7; P < 0.001), inhaled (HR1.2; P = 0.005) or systemic corticosteroids (HR1.8; P = 0.015) were significantly associated with exacerbation when having had no exacerbation at most recent visit. Higher FEV₁/FVC (HR0.9; P = 0.008) and higher FEV₁ values (HR0.9; P = 0.001) were protective. When already having had an exacerbation at the most recent visit, pronounced dyspnea (HR for mMRC grade 4 1.9; P = 0.026) and cerebrovascular insult (HR2.1; P = 0.003) were significantly associated with re-exacerbation. Physical activity (HR0.6; P = 0.031) and treatment with long-acting anticholinergics (HR0.7; P = 0.044) seemed to play a significant protective role. In a best subset model for exacerbation, higher FEV₁ significantly reduced and occurrence of sputum increased the probability of exacerbation. In the same model for re-exacerbation, coronary heart disease increased and hospitalization at most recent visit seemed to reduce the risk for re-exacerbation.

Conclusion

Our data confirmed well-established risk factors for exacerbations whilst analyzing their predictive association with exacerbation and re-exacerbation. This study confirmed the importance of spirometry in primary care, not only for diagnosis but also as a risk evaluation for possible future exacerbations.

Trial registration

Our study got approval by local ethical committee in 2006 (EK Nr. 170/06) and was registered retrospectively on ClinicalTrials.gov (NCT02065921, 19^th of February 2014).

Activin Type II Receptor Blockade for Treatment of Muscle Depletion in Chronic Obstructive Pulmonary Disease. A Randomized Trial

RATIONALE

Bimagrumab is a fully human monoclonal antibody that blocks the activin type II receptors, preventing the activity of myostatin and other negative skeletal muscle regulators.

OBJECTIVES

To assess the effects of bimagrumab on skeletal muscle mass and function in patients with chronic obstructive pulmonary disease (COPD) and reduced skeletal muscle mass.

METHODS

Sixty-seven patients with COPD (mean FEV1, 1.05 L [41.6% predicted]; aged 40-80 yr; body mass index < 20 kg/m2 or appendicular skeletal muscle mass index ≤ 7.25 [men] and ≤ 5.67 [women] kg/m2), received two doses of either bimagrumab 30 mg/kg intravenously (n = 33) or placebo (n = 34) (Weeks 0 and 8) over 24 weeks.

MEASUREMENTS AND MAIN RESULTS

We assessed changes in thigh muscle volume (cubic centimeters) as the primary endpoint along with 6-minute-walk distance (meters), safety, and tolerability. Fifty-five (82.1%) patients completed the study. Thigh muscle volume increased by Week 4 and remained increased at Week 24 in bimagrumab-treated patients, whereas no changes were observed with placebo (Week 4: +5.9% [SD, 3.4%] vs. 0.0% [3.3%], P < 0.001; Week 8: +7.0% [3.7%] vs. -0.7% [2.8%], P < 0.001; Week 16: +7.8% [5.1%] vs. -0.9% [4.5%], P < 0.001; Week 24: +5.0% [4.9%] vs. -1.3% [4.3%], P < 0.001). Over 24 weeks, 6-minute-walk distance did not increase significantly in either group. Adverse events in the bimagrumab group included muscle-related symptoms, diarrhea, and acne, most of which were mild in severity.

CONCLUSIONS

Blocking the action of negative muscle regulators through the activin type II receptors with bimagrumab treatment safely increased skeletal muscle mass but did not improve functional capacity in patients with COPD and low muscle mass. Clinical trial registered with www.clinicaltrials.gov (NCT01669174).

Unravelling the mystery of the 'minimum important difference' using practical outcome measures in chronic respiratory disease

It is important for clinicians and researchers to understand the effects of treatments on their patients, both at an individual and group level. In clinical studies, treatment effects are often reported as a change in the outcome measure supported by a measure of variability; for example, the mean change with 95% confidence intervals and a probability ( p) value to indicate the level of statistical significance. However, a statistically significant change may not indicate a clinically meaningful or important change for clinicians or patients to interpret. The minimum clinically important difference (MCID) or minimally important difference (MID) has therefore been developed to add clinical relevance or patient experience to the reporting of an outcome measure. In this article, we consider the concept of the MID using the example of practical outcome measures in patients with CRD. We describe the various ways in which an MID can be calculated via anchor- and distribution-based methods, looking at practical examples and considering the importance of understanding how an MID was derived when seeking to apply it to a particular situation. The terms MID and MCID are challenging and often used interchangeably. However, we propose all MIDs are described as such, but they could be qualified by a suffix: MIDS (MID - Statistical), MID-C (MID - Clinical outcome), MID-P (MID - Patient determined). However, this type of classification would only work if accepted and adopted. In the meantime, we advise clinicians and researchers to use an MID where possible to aid their interpretation of functional outcome measures and effects of interventions, to add meaning above statistical significance alone.

Upper-extremity function prospectively predicts adverse discharge and all-cause COPD readmissions: a pilot study

Background

Frailty can inform management approaches for individuals with COPD. However, inpatient measures of frailty are seldom employed because they are time-consuming or inapplicable for bed-bound patients. We investigated the feasibility and potential of an innovative sensor-based upper-extremity function (UEF) test for frailty assessment in predicting adverse outcomes.

Methods

Hospitalized patients with COPD-related exacerbations (aged ≥55 years) were recruited and performed the UEF test within 24 hours of admission. UEF parameters were obtained and fed into our previously developed frailty model to calculate frailty status (non-frail, pre-frail, and frail) and frailty score (0: extreme resilience to 1: extreme frailty). In-hospital (length of stay) and post-discharge (discharge disposition, 30-day exacerbation with treatment, and all-cause 30-day readmission) outcomes were collected. Associations between UEF frailty and outcomes were investigated using ANOVA and logistic models adjusted for demographic data.

Results

In total, 42 patients were recruited. All participants were able to perform the UEF test. Based on UEF, participants were stratified into three groups of non-frail (n=6, frailty score =0.18±0.09), pre-frail (n=14, frailty score =0.45±0.09), and frail (n=22, frailty score =0.78±0.11). Both frailty status and frailty score were significantly associated with unfavorable discharge disposition (P<0.005) and all-cause 30-day readmission (P<0.05). On the other hand, UEF frailty measures were associated with neither hospital length of stay (P>0.5) nor 30-day exacerbation with treatment (P>0.70). Age was only significantly associated with unfavorable discharge disposition (P=0.048).

Conclusion

In agreement with previous work, the current findings underline the importance of measuring frailty for risk-stratification of COPD patients. The UEF was feasible and easily performed among all hospitalized COPD patients. In this study, we have shown that, using our quick and objective frailty measures, COPD patients can be prospectively risk-stratified in terms of unfavorable discharge disposition and all-cause 30-day readmissions.

Pulmonary rehabilitation in patients with an acute exacerbation of chronic obstructive pulmonary disease

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are one of the most common causes of emergency hospital admission and place great burden upon healthcare systems. Furthermore, AECOPD represent an important life event for patients, and are associated with significant reductions in physical activity, skeletal muscle function, exercise tolerance and health-related quality of life. Pulmonary rehabilitation, an intervention comprising supervised exercise-training and education, may counteract these negative consequences and target modifiable risk factors for hospital readmission. A recent Cochrane systematic review included 20 randomized controlled trials comparing pulmonary rehabilitation after exacerbation of COPD versus conventional care. Overall, the evidence supports moderate to large effects on health-related quality of life and exercise capacity. However, there is substantial heterogeneity across studies, and more recent studies have been more equivocal, including around hospital readmissions, particularly when rehabilitation is started in the inpatient setting. In this narrative review, we examine the rationale for pulmonary rehabilitation following AECOPD with a particular focus on skeletal muscle function, review the current evidence for pulmonary rehabilitation in the AECOPD setting, and identify areas that require future research, including the structure and nature of the intervention, improving uptake and adherence, and the role of alternative rehabilitation strategies for patients with AECOPD.

Investigating the impact of intervention refusal on hospital readmission

OBJECTIVES

To identify characteristics and readmission risks associated with opting out of a social work-driven transition intervention.

STUDY DESIGN

Secondary data analysis of a randomized controlled pilot study at a large nonprofit urban community hospital.

METHODS

Hospitalized English-speaking, cognitively intact adults 65 years or older with expected discharge back to the community were eligible for enrollment. Additionally, patients met at least 1 of the 3 criteria: 1) 75 years or older, 2) taking 5 or more medications, or 3) had 1 or more prior inpatient stays or emergency department visits in the previous 6 months. The transition intervention consisted of up to 2 in-home visits (the first occurring within 48 hours after discharge) and up to 4 telephone follow-up calls (for a maximum of 6 total contacts) by a transition social worker. This study analyzed participants randomized to the intervention arm on measures including demographics, medical diagnoses, presence of advance directive, and all-cause 30-day hospital readmissions.

RESULTS

Of the 90 patients randomized to the Social Work Intervention Focused on Transitions intervention group, 10% were readmitted within 30 days and nearly one-third refused (ie, opted out of) the home visit component of the intervention. Multivariate analyses revealed that those opting out of the intervention had 3 times greater odds of having a respiratory condition compared with intervention recipients (odds ratio [OR], 3.10; 95% CI, 1.09-8.80; P = .034). Additionally, opting out of the intervention (OR, 6.75; 95% CI, 1.05-43.52; P = .045) and having a diagnosis of cancer (OR, 29.59; 95% CI, 2.01-435.45; P = .014) significantly predicted readmission.

CONCLUSIONS

Findings suggest that some at-risk patients may not be receptive to services and programs aimed at improving care transitions, resulting in a higher risk for readmission.