Development of the ESEx index: a tool for predicting risk of recurrent severe COPD exacerbations.

Background: In chronic obstructive pulmonary disease (COPD), multiple recurrent severe exacerbations that require hospitalization can occur. These events are strongly associated with death and other clinical complications. Objectives: We aimed to develop a prognostic model that could identify patients with COPD that are at risk of multiple recurrent severe exacerbations within 3 years. Design: Prospective cohort. Methods: The derivation cohort comprised patients with stable, moderate-to-severe COPD. Multivariable logistic regression analyses were performed to develop the final model. Based on regression coefficients, a simplified index (ESEx) was established. Both, model and index, were assessed for predictive performance by measuring discrimination and calibration. Results: Over 3 years, 16.4% of patients with COPD experienced at least three severe recurrent exacerbations. The prognostic model showed good discrimination of high-risk patients, based on three characteristics: the number of severe exacerbations in the previous year, performance in the five-repetition sit-to-stand test, and in the 6-minute-walk test. The ESEx index provided good level of discrimination [areas under the receiver operating characteristic curve (AUCs): 0.913]. Conclusions: The ESEx index showed good internal validation for the identification of patients at risk of three recurrent severe COPD exacerbations within 3 years. These tools could be used to identify patients who require early interventions and motivate patients to improve physical performance to prevent recurrent exacerbations.

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.

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.

Responsiveness and Minimal Clinically Important Difference of the Five Times Sit-to-Stand Test in Patients with Stroke.

This study aimed to analyze the responsiveness of the 5STS test among stroke patients and to estimate the MCIDs (minimal clinically important differences) for different severity levels of community ambulation and stages of recovery. The 5STS and comparator instruments (gait speed and Functional Ambulatory Category (FAC)) were evaluated at baseline. These measures were repeated at 4 (Stage 1) and 8 weeks (Stage 2), together with the Global Rating of Change (GROC). The MCIDs were calculated with two anchor-based methods using the GROC as the external criterion. Responsiveness to change for the 5STS was estimated analyzing the correlation with changes in the two comparator instruments and their capacity to discriminate improvement. For the 5STS test, while the MCIDs of the limited community ambulators were similar in the two stages (around 3 s), those of the household ambulators decreased from 1.9 s to 0.72 s. Spearman's rho coefficients showed an acceptable correlation between changes in 5STS and changes for both the FAC and gait speed changes in both stages of recovery. Our study revealed that the 5STS is responsive to functional changes in patients with stroke and that their degree of severity and stage of recovery influence the MCID values of the 5STS.

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.

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.