The accuracy with which the 5 times sit-to-stand test, versus gait speed, can identify poor exercise tolerance in patients with COPD: A cross-sectional study

Identifying COPD patients with poor health status and low exercise tolerance through the five-repetition sit-to-stand test and modified Medical Research Council Dyspnea Score

BACKGROUND

The objective of this study was to determine whether the concomitant presence of poor health status (COPD Assessment Test, CAT ≥ 10 points) and low exercise tolerance (6-Minute Walking Test, 6MWT < 350 m) is associated with worse clinical characteristics in patients with COPD. In addition, we aimed to develop a readily applicable diagnostic model to discriminate COPD patients with these conditions.

METHODS

A cross-sectional multicenter study involving 208 stable COPD patients (FEV1/FVC < 0.7, smoking history of at least 10 pack-years, and chronic respiratory symptoms) was carried out. The outcome measures were the 6MWT, CAT score, 5-repetition sit-to-stand test (5STS) and modified Medical Research Council Dyspnea Scale (mMRC). Patients were categorized into three groups: no condition (6MWT ≥ 350 m and CAT < 10 points), one condition (6MWT < 350 m or CAT ≥ 10 points), and both conditions (6MWT < 350 m and CAT ≥ 10 points).

RESULTS

A total of 26 patients (12,5%) presented both conditions. These patients experienced a higher degree of dyspnea (p = 0.001), smoking pack-years (p = 0.011), severe obstruction (p = 0.006), and time on 5STS (p = 0.001). The probability of having both conditions directly increased with the time spent on the 5STS (β=0.188; p = 0.010) and the degree of dyspnea (β=1.920; p < 0.001) (R2=0.413). The scoring system, using the 5STS and dyspnea as surrogate measures, demonstrated adequate calibration between the predicted and observed risk (linear R2=0.852).

CONCLUSIONS

COPD patients with concurrent conditions have worse clinical status. The diagnostic model developed to discriminate these patients shows good internal validation.

Estimation of Functional Aerobic Capacity Using the Sit-to-Stand Test in Older Adults with Heart Failure with Preserved Ejection Fraction

Background: The 6-Min Walking Test (6MWT) has been proposed to assess functional aerobic capacity in patients with heart failure, but many older adults with heart failure cannot complete it. The adequacy of the 5-repetition Sit-To-Stand (5-STS), a simpler test than 6MWT, to assess the functional aerobic capacity in older adults with heart failure has not been evaluated. Objectives: This study aimed to assess the usefulness of 5-STS in estimating maximal oxygen uptake (VO2 peak) in older adults with heart failure with preserved ejection fraction (HFpEF). Methods: A cross-sectional study was carried out. Patients 70 years and older with HFpEF were included. A bivariant Pearson correlation and subsequent multivariate linear regression analysis were used to analyze the correlations between the 5-STS and the estimated VO2 peak. Results: Seventy-six patients (80.74 (5.89) years) were recruited. The 5-STS showed a moderate and inversely correlation with the estimated VO2 peak (r = −0.555, p < 0.001). The 5-STS explained 40.4% of the variance in the estimated VO2 peak, adjusted by age, sex, and BMI. When older adults were stratified by BMI, the 5-STS explained 70% and 31.4% of the variance in the estimated VO2 peak in older adults with normal weight and overweight/obesity, respectively. Conclusions: The 5-STS may be an easy tool to assess functional aerobic capacity in older adults with HFpEF, especially for those with normal weight.

Optimal cutoff values for physical function tests in elderly patients with heart failure

Six-minute walk distance (6MWD) of 300 and 400 m are important targets of functional capacity. The present study was performed to determine cutoff values of physical function associated with 6MWD < 300 m and < 400 m in elderly patients with heart failure (HF). 6MWD, handgrip strength, quadriceps isometric strength (QIS), one-leg standing time (OLST), and 5-times sit-to-stand (5STS) before hospital discharge were evaluated in 1001 patients > 65 years (median age, 75: interquartile range, 71-80, 607 men) with HF. 6MWD < 300 and < 400 m were seen in 323 patients (32.3%) and 658 patients (65.7%), respectively. Handgrip strength, QIS, OLST, and 5STS were associated with 6MWD < 300 and < 400 m, respectively (P < 0.001). The cutoff values of handgrip strength, QIS, OLST, and 5STS were 18.9 kg, 35.0% body mass (BM), 9.1 s, and 9.5 s for 6MWD < 300 m, and 21.9 kg, 40.0% BM, 12.0 s, and 8.8 s for < 400 m, respectively. The cutoff values of physical function could be used to set cardiac rehabilitation goals and limiting determinants of reduced functional capacity in a clinical setting in elderly patients with HF.

Improving the Reliability Between the BODE Index and the BODS Index in Which the 6-Min Walk Test Was Replaced with the Five-Repetition Sit-to-Stand Test

Purpose

The BODS index has been confirmed to have predictive properties similar to the original BODE index for mortality in COPD. We evaluated the agreement between the BODS index and the BODE and explored with an updated BODS how this agreement could be improved and its ability to correctly discriminate individual participants’ mortality in a prospective cohort study.

Patients and Methods

We included prospectively a consecutive sample of 137 patients with COPD, between 40 and 80 years, during 2014 and followed for 5 years (2014–2019) in the Pneumology section of a public university hospital in Spain. They participated in the baseline data collection, which included BODE- and BODS-related measurements and prognostic factors, and were followed up for 5-year mortality. We used Bland–Altman plots and the kappa coefficient to analyze the agreement between both the original and updated BODS and the BODE index, and we used the areas under ROC curves (AUC) to compare their discriminative abilities for 5-year all-cause mortality.

Results

The original BODS index scores and quartiles had weak agreement with the BODE index, and our updated BODS strengthened these agreements (a small, statistically nonsignificant mean bias [<0.03] with LoAs<2 points, and a substantial Kappa coefficient [k =0.63; IC 95%: 0.53–0.73]). In addition, the updated BODS index scores had better summarized ability than the BODS index in discriminating participants’ mortality during the following 5 years (AUC: 0.768 versus 0.736; p=0.04).

Conclusion

The updated BODS index scores and quartiles may provide prognostic information similar to that provided by the BODE index in COPD. Future research should focus on index improvement through external validation, as well as the assessment of safety and effectiveness in clinical practice by means of impact studies.

The prognosis of pre-frail chronic obstructive pulmonary disease patients for hospitalizations and mortality depends on their level of functional physical performance

Objective

To determine if pre-frail Chronic obstructive pulmonary disease (COPD) patients with poor and non-poor performance in the five-repetition sit-to-stand test (5-STS) had a worse prognosis for hospitalization and mortality at 2 years and for mortality at 5 years than non-frail patients.

Methods

We prospectively included patients with stable COPD, between 40 and 80 years, from a hospital in Spain. Patients were classified according their performance on the 5-STS test and level of frailty. Timing, number of hospitalizations, length of stay, and timing and rate of mortality were outcome measures. Patients were followed for 2 years for exacerbations and for 5 years for mortality. Kaplan-Meier curves and univariate and multivariate Cox proportional-hazard analyses, ANOVA tests and univariate and multivariate linear and logistic regression models were used.

Results

Of the 125 patients included, 25.6% were pre-frail with poor performance, 57% pre-frail with non-poor performance, and 17.4% non-frail with non-poor performance. Pre-frail patients with poor performance had a higher number of hospitalizations (adjusted beta: 0.49; 95% CI: 0.01–0.96), mortality rates (odds ratio: 11.33; 95% CI: 1.15–110.81), and risk at 5 years (adjusted hazard ratio: 8.77; 95% CI: 1.02–75.51) than non-frail patients. Pre-frail patients with poor performance also had worse prognoses than non-frail patients with respect to length of hospital stays (increased by 4.16 days) and timing to first hospitalization (HR: 6.01) in unadjusted models, but not when adjusted.

Conclusion

The COPD prognosis of pre-frail patients with respect to the number of exacerbations with hospitalization and the timing and rate of mortality is dependent of functional performance.

Harnessing Digital Health to Objectively Assess Functional Performance in Veterans with Chronic Obstructive Pulmonary Disease

INTRODUCTION

An early detection of impaired functional performance is critical to enhance symptom management for patients with chronic obstructive pulmonary disease (COPD). However, conventional functional measures based on walking assessments are often impractical for small clinics where the available space to administrate gait-based test is limited. This study examined the feasibility and effectiveness of an upper-extremity frailty meter (FM) in identifying digital measures of functional performance and assessing frailty in COPD patients.

METHODS

Forty-eight patients with COPD (age = 68.8 ± 8.5 years, body mass index [BMI] = 28.7 ± 5.8 kg/m2) and 49 controls (age = 70.0 ± 3.0 years, BMI = 28.7 ± 6.1 kg/m2) were recruited. All participants performed a 20-s repetitive elbow flexion-extension test using a wrist-worn FM sensor. Functional performance was quantified by FM metrics, including speed (slowness), range of motion (rigidity), power (weakness), flexion and extension time (slowness), as well as speed and power reduction (exhaustion). Conventional functional measures, including timed-up-and-go test, gait and balance tests, and 5 repetition sit-to-stand test, were also performed.

RESULTS

Compared to controls, COPD patients exhibited deteriorated performances in all conventional functional assessments (d = 0.64-1.26, p < 0.010) and all FM metrics (d = 0.45-1.54, p < 0.050). FM metrics had significant agreements with conventional assessment tools (|r| = 0.35-0.55, p ≤ 0.001). FM metrics efficiently identified COPD patients with pre-frailty and frailty (d = 0.82-2.12, p < 0.050).

CONCLUSION

This study proposes the feasibility of using a 20-s repetitive elbow flexion-extension test and wrist-worn sensor-derived frailty metrics as an alternative and practical solution to evaluate functional performance in COPD patients. Its simplicity and low risk for test administration may also facilitate its application for remote patient monitoring. Furthermore, in settings where the administration of walking test is impractical, for example, when ventilator support is needed or space is limited, FM may be used as an alternative solution. Future studies are encouraged to use the FM to quantitatively monitor the progressive decline in functional performance and quantify outcomes of rehabilitation interventions.

Prediction of Reduced Gait Speed Using 5-Time Sit-to-Stand Test in Healthy Older Adults

OBJECTIVES

To determine the accuracy of the 5-time stand-to-sit (5TSTS) test for the identification of older adults with reduced gait speed.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

A total of 559 community-dwelling older adults were included in the study, divided into groups of women (n=465) and men (n=94).

METHODS

5TSTS and gait speed were assessed. Multiple linear regression analysis with adjustment was performed in order to determine the association between 5TSTS and gait speed, followed by the receiver operating characteristic (ROC) curve for the identification of the usefulness of 5TSTS to discriminate older adults with reduced gait speed. Based on the ROC curve, we identified the area under the curve, the sensitivity, specificity, and cutoff points of the 5TSST. Statistical analyses were made using the SPSS software (version 25.0), and a significance level of 5% (P ≤ .05) was adopted.

RESULTS

The 5TSTS showed correlation with gait speed. Additionally, 5TSTS was able to discriminate reduced gait speed with moderate accuracy (P < .05; AUC between 0.7 and 0.8). For women, the cutoff scores for 5TSTS to identify gait speed <0.8 m/s was 14.15 seconds; for gait speed <1.0 m/s, it was 12.67 seconds. For men, the cutoff scores for 5TSTS to identify gait speed <0.8 m/s was 14.67 seconds, and for gait speed <1.0 m/s, it was 13.63 seconds.

CONCLUSION AND IMPLICATIONS

The 5TSTS is clinically useful and can be an alternative assessment for discriminating community-dwelling older adults with reduced gait speed, when the gait evaluation is not feasible. The study also suggests different cutoff values for 5TSTS considering the gait speeds <0.8 and <1.0 m/s for older women and men, respectively.

Prognostic value of the five-repetition sit-to-stand test for mortality in people with chronic obstructive pulmonary disease

BACKGROUND

Prognostic studies suggest that some musculoskeletal and functional capacity tests are independently associated with mortality in chronic obstructive pulmonary disease (COPD), but comparing their prognostic value is difficult because of differences in the selected covariates for regression modelling in those studies.

OBJECTIVES

To assess the prognostic value of five musculoskeletal and functional capacity tests in predicting mortality risk in patients with COPD after adjusting for existing and confounding prognostic factors and to compare their ability to correctly discriminate the mortality of individual participants using the 6-min walk test (6MWT). We hypothesized that the examined tests have different prognostic value.

METHODS

Prospective and longitudinal study. A total of 137 patients with stable COPD (mean [SD] age 67 [8.33] years; 87% male) were recruited from a hospital in Spain during 2014 and followed for 5 years (2014-2019). No one refused and only one was lost to follow-up. The outcome measure was 5 year all-cause mortality.

RESULTS

A total of 37 patients died within 5 years. All musculoskeletal tests were associated with 5 year all-cause mortality in Cox proportional-hazards regression models. However, only the five-repetition sit-to-stand test (5-STS) score was an independent prognostic factor (hazard ratio 1.04 per sec, 95% confidence interval 1.01-1.08) after adjusting for history of heart disease, number of previous severe exacerbations, and dyspnoea. This model explained 50.7% of the variance in mortality. This test exhibited similar discriminative ability as the 6MWT for 5 year mortality (area under the receiver operating characteristic curve: 0.741vs 0.722; p = 0.92), and a highly prognostic cut-off for discriminating (15.98 s). This cut-off had higher likelihood ratios (LRs) than the 6MWT cut-off (∼350 m), especially for negative LRs (1/LR-: 7.69vs 2.00).

CONCLUSIONS

The 5-STS is an objective measure for predicting mortality in patients with COPD and has good discriminative ability, with a cut-off for discriminating survival slight better than the 6MWT. The prognostic value of the other tests remains to be confirmed.

Specific Contribution of Quadriceps Muscle Strength, Endurance, and Power to Functional Exercise Capacity in People With Chronic Obstructive Pulmonary Disease: A Multicenter Study

OBJECTIVE

Various functional muscle properties affect different aspects of functional exercise capacity in people with chronic obstructive pulmonary disease (COPD). The purpose of this study was to investigate the contribution of quadriceps muscle strength, endurance, and power to 6-Minute Walking Distance (6MWD) and 1-minute sit-to-stand test (1STS) performance in people with COPD.

METHODS

The study was a prospective, multicenter, cross-sectional study. Anthropometrics, Medical Research Council dyspnea scale, lung function, 6MWD, and 1STS number of repetitions were assessed. Isometric quadriceps strength and endurance, isotonic quadriceps endurance, isokinetic quadriceps strength, and power were assessed on a computerized dynamometer while functional quadriceps power was determined during 5 sit-to-stand repetitions. Univariate and multivariate analyses were performed to determine the contribution of functional muscle properties to the 6MWD and the 1STS number of repetitions.

RESULTS

The study included 70 people with COPD (mean % predicted forced expiratory volume in 1 second = 58.9 [SD = 18.2]). The 6MWD correlated with each functional muscle property except the isometric quadriceps endurance. The number of repetitions during the 1STS correlated with each functional muscle property except isometric measurements. Multivariate models explained 60% and 39% of the variance in the 6MWD and 1STS number of repetitions, respectively, with quadriceps power determined during 5 sit-to-stand repetitions being the muscle functional property with the strongest contribution to the models.

CONCLUSION

Except for isometric endurance, quadriceps strength, endurance, and power were associated with functional exercise capacity in people with moderate COPD. Among these functional muscle properties, muscle power contributed the most to the 6MWD and 1STS number of repetitions, suggesting that muscle power is more relevant to functional exercise capacity than muscle strength or endurance in people with COPD.

IMPACT

Understanding the individual contribution of muscle properties to functional status is important to designing interventions. This study provides the guidance that muscle power may be more important to functional exercise capacity than muscle strength or endurance in people with COPD.

[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.

Effectiveness of Non-Presential Individualized Exercise Training PrOgram(NIETO) in Lower Limb Physical Performance in Advanced COPD

Muscle training, a component of pulmonary rehabilitation (PR), improves the physical performance of patients with chronic obstructive pulmonary disease (COPD). Despite the existing evidence, the traditional center-based PR model is applied to a small percentage of patients and presents numerous problems of accessibility, adherence, and costs. This study presents a home model of simple muscle training, non-presential, monitored by telephone and individualized, according to the severity of the COPD. In addition, to evaluate the results, simple tests associated with the physical performance of the lower limbs, previously validated in COPD, have been used, such as the four-meter walk, speed test (4MGS) and the five-repetition test sitting and standing (5STS). The objective was to evaluate whether the Individualized Non-Presential Exercise Training PrOgram (NIETO) induces improvements in the 4MGS, 5STS and quadriceps muscle strength (QMS) tests in outpatients with advanced COPD (FEV1 ≤ 50%). After one year, the QMS was significantly higher in the intervention group (IG) than in the control group (CG) (2.44 ± 4.07 vs. 0.05 ± 4.26 kg; p = 0.009). The 4MGS and 5STS tests were significantly shorter in IG than in CG (−0.39 ± 0.86 vs. 0.37 ± 0.96 s; p = 0.001) and (−1.55 ± 2.83 vs. 0.60 ± 2.06 s; p = 0.001), respectively. A home model of simple muscle training monitored by telephone such as NIETO, can improve 4MGS, 5STS, and quadriceps strength tests in outpatients with advanced COPD.

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.

Is it Possible to Use the Timed Performance Tests in Lung Transplantation Candidates to Determine the Exercise Capacity?

OBJECTIVES

Lung transplantation (LTx) candidates have severe exercise intolerance. This makes it difficult for them to complete the field tests used to determine the exercise capacity of patients. Therefore, there is a need for alternative tests that require less effort. We aimed to investigate the use of short-timed performance tests instead of 6-minute walk test (6MWT) in the determination of exercise capacity in LTx.

MATERIALS AND METHODS

A total of 63 LTx candidates were included in the study. Ten-meter walking speed test (10MWT), 5-times sit-to-stand test (5XSST), 6MWT were performed at one-hour intervals within the same day, and by the same physiotherapist in all patients. Maximal inspiratory (MIP) and expiratory pressure (MEP), peripheral muscle strengths, pulmonary function tests, and body mass index (BMI) were recorded for each patient.

RESULTS

The subjects' baseline mean 6-minute walking distance (6MWD) was 336m, 5XSST time was 11.59 sec, and 10MWT time was 8.45sec. There was a negative and moderate correlation between 6MWD and 10MWT (p<0.001, r=0.449). Similarly there was a negative but weak correlation between 6MWD and 5XSST (p=0.001, r=0.397). In addition, there was a strong relationship between 5XSST and 10MWT (p<0.001, r=0.767).

CONCLUSION

This study showed that 6MWT and short-timed performance tests were correlated in terms of exercise capacity assessment. In contrast, there was a strong relationship between 6MWT and 10MWT according to 6MWT and 5XSST. The timed performance tests may be alternative tests to determine exercise capacity in LTx candidates.

Home-based or remote exercise testing in chronic respiratory disease, during the COVID-19 pandemic and beyond: A rapid review

Objectives:

To identify exercise tests that are suitable for home-based or remote administration in people with chronic lung disease.

Methods:

Rapid review of studies that reported home-based or remote administration of an exercise test in people with chronic lung disease, and studies reporting their clinimetric (measurement) properties.

Results:

84 studies were included. Tests used at home were the 6-minute walk test (6MWT, two studies), sit-to-stand tests (STS, five studies), Timed Up and Go (TUG, 4 studies) and step tests (two studies). Exercise tests administered remotely were the 6MWT (two studies) and step test (one study). Compared to centre-based testing the 6MWT distance was similar when performed outdoors but shorter when performed at home (two studies). The STS, TUG and step tests were feasible, reliable (intra-class correlation coefficients >0.80), valid (concurrent and known groups validity) and moderately responsive to pulmonary rehabilitation (medium effect sizes). These tests elicited less desaturation than the 6MWT, and validated methods to prescribe exercise were not reported.

Discussion:

The STS, step and TUG tests can be performed at home, but do not accurately document desaturation with walking or allow exercise prescription. Patients at risk of desaturation should be prioritised for centre-based exercise testing when this is available.

Patterns and predictors of low physical activity in patients with stable COPD: a longitudinal study

Background:

Despite the frequency and negative impact of low physical activity among patients with chronic obstructive pulmonary disease (COPD), little is known about how it persists and remits over time or the factors predicting new states of low physical activity. The aim of the study was to determine the probability of a transition between states of low and nonlow physical activity in a cohort of patients with stable COPD followed for 2 years. We also investigated different potentially modifiable factors to determine whether they can predict new states of low physical activity.

Methods:

We prospectively included 137 patients with stable COPD (mean age 66.9 ± 8.3 years). Physical activity was measured at baseline and at 1 and 2 years of follow up. Low physical activity was defined according to energy expenditure by cut-off points from the Fried frailty model. The likelihood of annual transition towards new states and recovery was calculated. We evaluated demographic, frailty, nonrespiratory, and respiratory variables as potential predictors, using generalized estimating equations.

Results:

At baseline, 37 patients (27%) presented with low physical activity. During the study period, a total of 179 annual transitions were identified with nonlow physical activity at the beginning of the year; 17.5% transitioned to low physical activity. In contrast, 34.3% of the 67 transitions that started with low physical activity recovered. Predictors of transition to new states of low physical activity were dyspnea ⩾2 (odds ratio = 3.21; 95% confidence interval: 1.20–8.61) and poor performance on the five sit-to-stand test (odds ratio = 4.75; 95% confidence interval: 1.30–17.47).

Conclusions:

The change between levels of low and nonlow physical activity is dynamic, especially for recovery. Annual transitions toward new states of low physical activity are likely among patients with dyspnea or poor performance on the five sit-to-stand test.

The reviews of this paper are available via the supplemental material section.

Stability and Predictors of Poor 6-min Walking Test Performance over 2 Years in Patients with COPD

Poor performance in the 6-min walk test (6MWT < 350 m) is an important prognostic indicator of mortality and risk of exacerbations in patients with chronic obstructive pulmonary disease (COPD). Little is known about the stability of this state over time and what factors might predict a poor 6MWT performance. To determine the stability of 6MWT performance over a 2-year period in COPD patients participating in annual medical follow-up visits, and to assess the ability of several clinical, pulmonary, and non-pulmonary factors to predict poor 6MWT performance, we prospectively included 137 patients with stable COPD (mean age, 66.9 ± 8.3 years). The 6MWT was scored at baseline and 2-year follow-up. To evaluate clinical, pulmonary, and non-pulmonary variables as potential predictors of poor 6MWT performance, we used multiple logistic regression models adjusted for age, sex, weight, height, and 6MWT performance at baseline. Poor 6MWT performance was stable over 2 years for 67.4% of patients. Predictors of poor 6MWT performance included a five-repetition sit-to-stand test score ≤2 (OR, 3.01; 95% CI, 1.22-7.42), the percentage of mobility activities with limitations (OR, 1.03; 95% CI, 1.00-1.07), and poor 6MWT performance at baseline (OR, 4.64; 95% CI, 1.88-11.43). Poor 6MWT performance status was stable for the majority of COPD patients. Lower scores on the five-repetition sit-to-stand test and a higher number of mobility activities with limitations were relevant predictors of poor 6MWT performance over 2 years. Prognostic models based on these non-pulmonary factors can provide non-inferior discriminative ability in comparison with prognostic models based on only pulmonary factors.

Frailty transitions and associated clinical outcomes in patients with stable COPD: A longitudinal study

BACKGROUND

Although frailty is a frequent occurrence in chronic obstructive pulmonary disease (COPD) patients, evidence on the frequency of frailty transition is scarce.

AIMS

The present study aimed to describe the frailty status transition rates over a 2-year period and their associated clinical outcomes in stable COPD patients, and to determine predictors of improvement in frailty status.

METHODS

We prospectively included 119 patients with stable COPD (mean age ± SD, 66.9 ± 7.9 years) over a follow-up period of 2 years. Frailty was assessed using the Fried criteria (unintentional weight loss, weakness, exhaustion, low activity level, and slow walking speed). Several demographic, clinical, and health-related variables were measured. We calculated the rates for each of the frailty transitions (no change, improvement, or worsening) between baseline and 2 years. Outcomes were compared using one-way analysis of variance and predictors of improvement were identified in multivariate logistic regression.

RESULTS

After 2 years of follow-up, 21 (17.6%) patients had an improved frailty status, 14 (11.7%) had worsened, and 84 (70.5%) had maintained the same frailty status. The worsening group (vs no change group) had greater dyspnea (p = 0.013) and disability (p = 0.036) and lower handgrip strength (p = 0.001). In contrast, the improved group (vs no change group) had greater handgrip (p<0.001) and quadriceps strength (p = 0.032). Furthermore, the improved group had greater handgrip strength (p<0.001), quadriceps strength (p = 0.003), physical activity (p = 0.008), and lower disability (p = 0.019) than the worsening group. Additionally, we determined that the 5STS test (≤ 13.6s) and exacerbations (≥ 2) were independent predictors for improvement in frailty status [adjusted OR 9.46, p = 0.058 and adjusted OR 0.12, p = 0.026, respectively].

CONCLUSIONS

Frailty is a dynamic process for approximately one-third of patients with stable COPD and transitions in frailty status are associated with significant changes in clinical outcomes. The 5STS and exacerbations were independent predictors of improvement in frailty status.

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.

Associations between the measures of physical function, risk of falls and the quality of life in haemodialysis patients: a cross-sectional study

BACKGROUND

Impaired physical function due to muscle weakness and exercise intolerance reduces the ability to perform activities of daily living in patients with end-stage kidney disease, and by consequence, Health-Related Quality of Life (HRQoL). Furthermore, the risk of falls is an aggregate of physical function and, therefore, could be associated with HRQoL as well. The present study examined the associations between objective and subjective measures of physical function, risk of falls and HRQoL in haemodialysis patients.

METHODS

This cross-sectional multicentre study included patients on maintenance haemodialysis. Physical function (quadriceps force, handgrip force, Sit-to-Stand, and six-minute walking test), the risk of falls (Tinetti, FICSIT-4, and dialysis fall index) and HRQoL (PROMIS-29 and EQ-5D-3 L) were measured and analysed descriptively, by general linear models and logistic regression.

RESULTS

Of the 113 haemodialysis patients (mean age 67.5 ± 16.1, 57.5% male) enrolled, a majority had impaired quadriceps force (86.7%) and six-minute walking test (92%), and an increased risk of falls (73.5%). Whereas muscle strength and exercise capacity were associated with global HRQoL (R² = 0.32) and the risk of falls, the risk of falls itself was related to psycho-social domains (R² = 0.11) such as depression and social participation, rather than to the physical domains of HRQoL. Objective measures of physical function were not associated with subjective fatigue, nor with subjective appreciation of health status.

CONCLUSIONS

More than muscle strength, lack of coordination and balance as witnessed by the risk of falls contribute to social isolation and HRQoL of haemodialysis patients. Mental fatigue was less common than expected, whereas, subjective and objective physical function were decreased.

Patterns and Predictors of Recovery from Poor Health Status Measured with the Chronic Obstructive Pulmonary Disease (COPD) Assessment Test in Patients with Stable COPD: A Longitudinal Study

Recent recommendations for chronic obstructive pulmonary disease (COPD) suggest that evaluation and management should focus on patient health status. Despite the frequency of poor health status and its negative impact on patients with COPD, little is known about how poor or non-poor health status persists and/or remits over time or what factors might predict recovery from a poor health status. The aim was to determine the likelihood of transitioning between poor and non-poor health status in patients with stable COPD followed for 2 years and to investigate factors that might predict recovery from poor health status. We prospectively included 137 patients with stable COPD (mean age, 66.9 years ± 8.3). Health status was measured at baseline and after 1 and 2 years with the COPD assessment test (CAT). Higher scores indicated worse health status, and 10 was the cut-off score for discriminating between non-poor and poor health status. The likelihoods of annual transitions to new episodes and recovery were calculated. We evaluated demographic, non-respiratory, and respiratory variables as potential predictors with generalized estimating equations. At baseline, 37 patients (27%) reported non-poor health status. Within the group of patients displaying poor health status at the beginning of the year, 176 annual transitions were identified during the study period: 15.9% were transitions to recovery from poor health status. In contrast, of the 70 transitions from a starting non-poor health status, 32.4% worsened. Predictors of transitions to recovery were: current non-smoker status (odds ratio (OR) = 3.88; 95% confidence interval (CI): 0.64–5.54) and handgrip strength (OR = 1.08; 95% CI: 1.00–1.16). This study suggests that self-reported health status, measured with the CAT, has a dynamic nature in patients with COPD. Annual transitions towards recovery from poor health status are most likely among current non-smoking patients and those with high handgrip strength.

Enhancing our understanding of the time course of acute exacerbations of COPD managed on an outpatient basis

Purpose

Acute exacerbations of COPD (AECOPD) are associated with pulmonary/systemic changes; however, quantification of those changes during AECOPD managed on an outpatient basis and factors influencing recovery are lacking. This study aimed to characterize patients’ changes during AECOPD and identify factors influencing their recovery.

Methods

Body mass index, the modified British Medical Research Council questionnaire, number of exacerbations in the previous year, and the Charlson comorbidity index (independent variables) were collected within 24–48 hours of hospital presentation (T0). Peripheral oxygen saturation (SpO₂), forced expiratory volume in one second, percentage predicted (FEV₁% predicted), maximum inspiratory pressure, quadriceps muscle strength, 5 times sit-to-stand, and COPD assessment test (CAT) (dependent variables) were collected at T0 and approximately at days 8 (T1), 15 (T2), and 45 (T3) after T0.

Results

A total of 44 outpatients with AECOPD (31♂; 68.2±9.1 years; 51.1±20.3 FEV₁% predicted) were enrolled. All variables improved overtime (P<0.05); however, at day 8, only SpO₂ and CAT (P≤0.001) showed significant improvements. Changes in FEV₁% predicted and SpO₂ were not influenced by any independent measure, while changes in other outcome measures were influenced by at least one of the independent measures. Independently of the time of data collection, being underweight or overweight and having increased dyspnea, previous exacerbations, and severe comorbidities negatively affected patients’ outcomes.

Conclusion

FEV₁% predicted and SpO₂ were not influenced by any independent measure and, thus, seem to be robust measures to follow-up outpatients with AECOPD. No single indicator was able to predict patients’ recovery for all measures; thus, a comprehensive assessment at the onset of the AECOPD is required to personalize interventions.

A comparative study of the five-repetition sit-to-stand test and the 30-second sit-to-stand test to assess exercise tolerance in COPD patients

Purpose

The sit-to-stand test (STST) has been used to evaluate the exercise tolerance of patients with COPD. However, mutual comparisons to predict poor exercise tolerance have been hindered by the variety of STST modes used in previous studies, which also did not consider patients’ subjective perceptions of different STST modes. Our aim was to compare the five-repetition sit-to-stand test (5STS) with the 30-second sit-to-stand test (30STS) for predicting poor performance in the six-minute walking test and to evaluate patients’ subjective perceptions to determine the optimal mode for clinical practice.

Patients and methods

Patients with stable COPD performed 5STS, 30STS and the 6MWT and then evaluated their feelings about the two STST modes by Borg dyspnea score and a questionnaire. Moreover, we collected data through the pulmonary function test, mMRC dyspnea score, COPD assessment test and quadriceps muscle strength (QMS). A receiver operating characteristic curve analysis of the 5STS and 30STS results was used to predict 6-minute walk distance (6MWD) <350 m.

Results

The final analysis included 128 patients. Similar moderate correlations were observed between 6MWT and 5STS (r=−0.508, P<0.001) and between 6MWT and 30STS (r=0.528, P<0.001), and there were similar correlations between QMS and 5STS (r=−0.401, P<0.001) and between QMS and 30STS (r=0.398, P<0.001). The 5STS and 30STS score cutoffs produced sensitivity, specificity and positive and negative predictive values of 76.0%, 62.8%, 56.7% and 80.3% (5STS) and 62.0%, 75.0%, 62.0% and 75.0% (30STS), respectively, for predicting poor 6MWT performance. The 5STS exhibited obvious superiority in terms of the completion rate and the subjective feelings of the participants.

Conclusion

As a primary screening test for predicting poor 6MWD, the 5STS is similar to the 30STS in terms of sensitivity and specificity, but the 5STS has a better patient experience.

Measurement Properties of Short Lower Extremity Functional Exercise Tests in People With Chronic Obstructive Pulmonary Disease: Systematic Review

BACKGROUND

An increasing variety of short functional exercise tests are reported in people with chronic obstructive pulmonary disease (COPD). Systematic review of the psychometric properties of these exercise tests is indicated.

PURPOSE

The aim of this study was to determine the reliability, validity, and responsiveness of short (duration < 6 min) lower extremity functional exercise tests in people with COPD.

DATA SOURCES

Five databases were searched: MEDLINE, Embase, Scopus, AMED, and CINAHL.

STUDY SELECTION

Studies reporting psychometric properties of short functional exercise tests in people with COPD were included.

DATA EXTRACTION

Two reviewers independently extracted data and rated the quality of each measurement property using the COnsensus-based Standards for the Selection of Health Measurement INstrument (COSMIN).

DATA SYNTHESIS

Twenty-nine studies were identified reporting properties of 11 different tests. Four-meter gait speed [4MGS] and 5 repetition sit-to-stand [5STS] demonstrated high reliability (ICC = .95-.99; .97) with no learning effect (COSMIN study ratings = good--excellent). Their validity for use as a stratification tool anchored against an established prognostic indicator (area under receiver operator characteristics curve [AUC] = 0.72-0.87; 0.82) and responsiveness to change after pulmonary rehabilitation was greatest in more frail people with COPD. Studies of the Timed "Up and Go" [TUG] test support use of a practice test and show discriminative ability to detect falls history and low six-minute walk distance (AUC = 0.77; 0.82, COSMIN ratings = fair-excellent).

LIMITATIONS

Earlier studies were limited by small sample size. Limited data of lower study quality was identified for step tests and the Two-Minute Walk Test.

CONCLUSIONS

Selected short functional exercise tests can complement established exercise capacity measures, in stratification and measuring responsiveness to change especially in people with COPD and lower functional ability.