Predictors of mortality in patients with COPD after 9 years

Identification of sleep phenotypes in COPD using machine learning-based cluster analysis

BACKGROUND

Disturbed sleep in patients with COPD impact quality of life and predict adverse outcomes.

RESEARCH QUESTION

To identify distinct phenotypic clusters of patients with COPD using objective sleep parameters and evaluate the associations between clusters and all-cause mortality to inform risk stratification.

STUDY DESIGN AND METHODS

A longitudinal observational cohort study using nationwide Veterans Health Administration data of patients with COPD investigated for sleep disorders. Sleep parameters were extracted from polysomnography physician interpretation using a validated natural language processing algorithm. We performed cluster analysis using an unsupervised machine learning algorithm (K-means) and examined the association between clusters and mortality using Cox regression analysis, adjusted for potential confounders, and visualized with Kaplan-Meier estimates.

RESULTS

Among 9992 patients with COPD and a clinically indicated baseline polysomnogram, we identified five distinct clusters based on age, comorbidity burden and sleep parameters. Overall mortality increased from 9.4 % to 42 % and short-term mortality (<5.3 years) ranged from 3.4 % to 24.3 % in Cluster 1 to 5. In Cluster 1 younger age, in 5 high comorbidity burden and in the other three clusters, total sleep time and sleep efficiency had significant associations with mortality.

INTERPRETATION

We identified five distinct clinical clusters and highlighted the significant association between total sleep time and sleep efficiency on mortality. The identified clusters highlight the importance of objective sleep parameters in determining mortality risk and phenotypic characterization in this population.

Dynamic hyperinflation is a risk factor for mortality and severe exacerbations in COPD patients

OBJECTIVE

To assess if dynamic hyperinflation is an independent risk factor for mortality and severe exacerbations in COPD patients.

METHODS

A cohort of 141 patients with stable COPD and moderate to very severe airflow limitation, treated according to conventional guidelines, was followed for a median of 9 years. Clinical characteristics were recorded and arterial blood gases, pulmonary function tests, 6-min walk and incremental exercise test with measurement of respiratory pattern and operative lung volumes were performed. Endpoints were all-cause mortality and hospitalization for COPD exacerbation.

RESULTS

58 patients died during the follow-up period (1228 patients x year). The mortality rate was higher in patients with dynamic hyperinflation (n = 106) than in those without it (n = 35) (14.6; 95% CI, 14.5-14.8 vs. 7.2; 95% CI, 7.1-7.4 per 1000 patients-year). After adjusting for sex, age, body mass index, pack-years and treatment with inhaled corticosteroids, dynamic hyperinflation was associated with a higher mortality risk (adjusted hazard ratio [aHR], 2.725; 95% CI, 1.010-8.161), and in a multivariate model, comorbidity, peak oxygen uptake and dynamic hyperinflation were retained as independent predictors of mortality. The time until first severe exacerbation was shorter for patients with dynamic hyperinflation (aHR, 3.961; 95% CI, 1.385-11.328), and dynamic hyperinflation, FEV1 and diffusing capacity were retained as independent risk factors for severe exacerbation. Moreover, patients with dynamic hyperinflation had a higher hospitalization risk than those without it (adjusted incidence rate ratio, 1.574; 95% CI, 1.087-2.581).

CONCLUSION

In stable COPD patients, dynamic hyperinflation is an independent prognostic factor for mortality and severe exacerbations.

Association between computed tomography-quantified respiratory muscles and chronic obstructive pulmonary disease: a retrospective study

BACKGROUND

This study examined the association between chest muscles and chronic obstructive pulmonary disease (COPD) and the relationship between chest muscle areas and acute exacerbations of COPD (AECOPD).

METHODS

There were 168 subjects in the non-COPD group and 101 patients in the COPD group. The respiratory and accessory respiratory muscle areas were obtained using 3D Slicer software to analysis the imaging of  computed tomography (CT). Univariate and multivariate Poisson regressions were used to analyze the number of AECOPD cases during the preceding year. The cutoff value was obtained using a receiver operating characteristic (ROC) curve.

RESULTS

We scanned 6342 subjects records, 269 of which were included in this study. We then measured the following muscle areas (non-COPD group vs. COPD group): pectoralis major (19.06 ± 5.36 cm2 vs. 13.25 ± 3.71 cm2, P < 0.001), pectoralis minor (6.81 ± 2.03 cm2 vs. 5.95 ± 1.81 cm2, P = 0.001), diaphragmatic dome (1.39 ± 0.97 cm2 vs. 0.85 ± 0.72 cm2, P = 0.011), musculus serratus anterior (28.03 ± 14.95 cm2 vs.16.76 ± 12.69 cm2, P < 0.001), intercostal muscle (12.36 ± 6.64 cm2 vs. 7.15 ± 5.6 cm2, P < 0.001), pectoralis subcutaneous fat (25.91 ± 13.23 cm2 vs. 18.79 ± 10.81 cm2, P < 0.001), paravertebral muscle (14.8 ± 4.35 cm2 vs. 13.33 ± 4.27 cm2, P = 0.007), and paravertebral subcutaneous fat (12.57 ± 5.09 cm2 vs. 10.14 ± 6.94 cm2, P = 0.001). The areas under the ROC curve for the pectoralis major, intercostal, and the musculus serratus anterior muscle areas were 81.56%, 73.28%, and 71.56%, respectively. Pectoralis major area was negatively associated with the number of AECOPD during the preceding year after adjustment (relative risk, 0.936; 95% confidence interval, 0.879-0.996; P = 0.037).

CONCLUSION

The pectoralis major muscle area was negative associated with COPD. Moreover, there was a negative correlation between the number of AECOPD during the preceding year and the pectoralis major area.

Insomnia in chronic obstructive pulmonary disease and associations with healthcare utilization and costs

Insomnia has been linked to adverse chronic obstructive pulmonary disease (COPD) outcomes including exacerbations, yet its impact on COPD-related healthcare utilization and costs is unknown. In this study, we investigated the associations between insomnia and healthcare utilization and costs in patients with COPD. A retrospective cohort of veterans with COPD were identified from national Veterans Affairs administration data for fiscal years 2012-2017. Insomnia was operationalized as having an insomnia diagnosis based on International Classification of Disease codes or having a prescription of > 30 doses of a sedative-hypnotic medication in a given fiscal year. The index date for insomnia was the first date when dual criteria for COPD and insomnia was met. The index date for those without insomnia was set as the COPD index date. Our primary outcomes were 1-year healthcare utilization and costs related to outpatient visits and hospitalizations after index date. COPD-related healthcare utilization variables included number of prescription fills of corticosteroids and/or antibiotics and outpatient visits and hospitalizations with a primary diagnosis of COPD. Out of 1,011,646 patients (96% men, mean age 68.4 years) diagnosed with COPD, 407,363 (38.8%) had insomnia. After adjustment for confounders, insomnia was associated with higher rates of outpatient visits, hospitalizations, and fills for corticosteroids and/or antibiotics, longer hospital length of stay, and $10,344 higher hospitalization costs in the 12 months after index date. These findings highlight the importance of insomnia as a potentially modifiable target for reducing the burden of COPD on patients and healthcare systems.

The Role of Early Warning Scoring Systems NEWS and MEWS in the Acute Exacerbation of COPD

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are the most devastating events in the course of the disease. Our aim was to investigate the value of early warning scoring systems: National Early Warning Score (NEWS) and Modified Early Warning Score (MEWS) in AECOPD. This is a prospective observational study of patients with AECOPD who were admitted at hospital. The NEWS and MEWS scores were registered at admission (NEWS-d1, MEWS-d1) and on the second day (NEWS-d2, MEWS-d2). A nasopharyngeal and sputum sample was taken for culture. Follow-up was done at 3 and 6 months after hospitalization. Any possible correlations between NEWS and MEWS and other parameters of COPD were explored. A cohort of 64 patients were included. In-hospital mortality was 4.7% while total mortality at 6 months was 26%. We did not find any significant correlation between in-hospital mortality and any of the scores but we could show a higher mortality and more frequent AECOPD at 6 months of follow-up for those with higher NEWS-d2. NEWS-d2 was associated with higher pCO₂ at presentation and a more frequent use of NIV. Higher NEWS-d1 and NEWS-d2 were predictive of a longer hospital stay. The presence of pathogens in the nasopharyngeal sample was related with a higher reduction of both scores on the second day. We therefore support the superiority of NEWS in the evaluation of hospitalized patients with AECOPD. A remaining high NEWS at the second day of hospital stay signals a high risk of hypercapnia and need of NIV but also higher mortality and more frequent exacerbations at 6 months after AECOPD.

Stability of distinct symptom experiences in patients with chronic obstructive pulmonary disease (COPD)

PURPOSE

This study aimed to examine reclassification rates among classes of chronic obstructive pulmonary disease (COPD) patients based on their distinct symptom experiences and to assess how these subgroups differed in symptom scores and health-related quality of life (HRQoL) outcomes over one year. Moreover, we wished to assess how these subgroups differed in demographic and clinical characteristics at 12 months.

PATIENTS AND METHODS

This is a follow-up study of 267 patients with moderate, severe, and very severe COPD. Based on their distinct symptom experiences using the Memorial Symptom Assessment Scale (MSAS), three subgroups (i.e., "high", "intermediate", and "low") were identified at baseline. In the present study, transitions between the subgroups at three, six, nine, and 12 months were investigated and calculated as reclassification rates. Differences among the subgroups in symptom scores and HRQoL at each time point and demographic and clinical characteristics at 12 months were evaluated using analysis of variance with post hoc comparisons.

RESULTS

Almost 65% were still in the "high" class after 12 months. At 12 months, pairwise comparisons for respiratory function measurements were not significantly different. Compared to the "intermediate" and "low" class, patients in the "high" class were more likely to be women and had significantly more comorbidities, reported a significantly higher number of symptoms at all time points, and worse HRQoL scores.

CONCLUSION

Our findings suggest that the pattern of a high symptom burden in COPD is consistent over time. The patients' individual symptom experiences should be the primary focus of treatment.

The Obesity Paradox in Chronic Heart Disease and Chronic Obstructive Pulmonary Disease

Obesity in recent years has become an epidemic. A high body mass index (BMI) is one of today's most crucial population health indicators. BMI does not directly quantify body fat but correlates well with easier body fat measurements. Like smoking, obesity impacts multiple organ systems and is a major modifiable risk factor for countless diseases. Despite this, reports have emerged that obesity positively impacts the prognosis of patients with chronic illnesses such as chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD), a phenomenon known as the Obesity Paradox. This article attempts to explain and summarize this phenomenon.

As it stands, two theories explain this paradox. The muscle mass hypothesis states that obese patients are better adapted to tide through acute exacerbations due to increased reserve because of greater muscle mass. The other theory focuses on brown adipose tissue and its anti-inflammatory effects on the body.

We performed a literature review on research articles published in English from 1983 to the present in the following databases - PubMed, Elsevier, and Google Scholar. The following search strings and Medical Subject Headings (MeSH) terms were used: "Obesity," "Heart Failure," "COPD," and "Cardio-Respiratory Fitness." In this review, we looked at the obesity paradox in Heart Failure and COPD. We summarized the current literature on the Obesity Paradox and reviewed its relationship with Cardio-Respiratory Fitness.

"Can Do, Do Do" Quadrants and 6-Year All-Cause Mortality in Patients With COPD

BACKGROUND

Physical capacity (PC; "can do") and physical activity (PA; "do do") are prognostic indicators in COPD and can be used to subdivide patients with COPD into four exclusive subgroups (the so-called "can do, do do" quadrants). This concept may be useful to understand better the impact of PC and PA on all-cause mortality in patients with COPD.

RESEARCH QUESTION

What is the 6-year all-cause mortality risk of the "can do, do do" quadrants of patients with COPD?

STUDY DESIGN AND METHODS

This retrospective study used data from patients with COPD who underwent a comprehensive assessment at their first-ever outpatient consultation. PC was assessed using the 6-min walk distance and physical activity was assessed using an accelerometer (steps per day). All-cause mortality data were obtained from the Municipal Personal Records Database. Receiver operating characteristic curves were used to determine threshold values for PC and PA to predict 6-year all-cause mortality. Using the derived threshold values, male and female patients were divided into the four "can do, do do" quadrants.

RESULTS

Data from 829 patients were used for analyses. Best discriminatory values for 6-year mortality were 404 m and 4,125 steps/day for men and 394 m and 4,005 steps/day for women. During a median follow-up of 55 months (interquartile range, 37-71 months), 129 patients (15.6%) died. After controlling for established prognostic factors, patients in the "can do, don't do" quadrant and "can do, do do" quadrant showed significantly lower mortality risk compared with patients in the "can't do, don't do" quadrant: hazard ratios of 0.36 (95% CI, 0.14-0.93) and 0.24 (95% CI, 0.09-0.61) for men and 0.37 (95% CI, 0.38-0.99) and 0.29 (95% CI, 0.10-0.87) for women, respectively. No significant differences were found between the "can't do, do do" and "can't do, don't do" quadrants.

INTERPRETATION

Patients with COPD with a preserved PC seem to have a significantly lower 6-year mortality risk compared with patients with a decreased PC, regardless of physical activity level.

Triple Therapy in COPD: Can We Welcome the Reduction in Cardiovascular Risk and Mortality?

Chronic obstructive pulmonary disease (COPD) is a complex disease which consists in the reduction of the airflow and leads to the disruption of the pulmonary tissue due to a chronic inflammation. The progression of the disease is characterized by an exacerbation of the symptoms and the presence of life-threatening systemic complications, such as stroke and ischemic heart disease, with a progressive decline in lung function which can deeply impact the quality of life. Mortality represents the most important COPD outcome, with an increased risk in patients with cardiovascular comorbidities. The efficacy and safety of triple inhaled therapy were demonstrated by numerous controlled trials. Above all, many robust data are now available on the effectiveness of the triple therapy to reduce mortality in COPD patients.

Nine-Year Follow-Up of Interleukin 6 in Chronic Obstructive Pulmonary Disease - Complementary Results from Previous Studies

Background

Systemic manifestations of chronic obstructive pulmonary disease (COPD) are related to increased systemic inflammatory process; however, it is not entirely clear how much they are related and how the systemic inflammation, in particular interleukin-6 (IL-6), is associated with exacerbation and mortality risk.

Objective

To evaluate the role of IL-6 in COPD patients over nine years.

Study Design and Methods

A total of 133 COPD patients were assessed at baseline between 2004 and 2006 and reassessed after three and nine years through clinical evaluation, comorbidities, hematological blood count and IL-6 analysis.

Results

After nine years, 19 patients lost the follow-up and were not possible to identify the date of death of four patients; 12 refused to participate and 1 could not be involved due to recurrent exacerbations. Therefore, 33 patients were included in the reassessment after nine years of follow-up and 92 patients were included in the Cox mortality analysis with IL-6 as a time-dependent covariate. Regarding the inflammatory profile, in patients who survived after nine years, there was a significant increase in IL-6 [0.4 (0.2–0.8) vs 5.7 (3.4–11) pg/mL; p < 0.001] and reduction in lymphocyte count [2.1 (1.6–2.4) vs 1.4 (1.2–2.1)10^9/L; p < 0.01] with an increase in the neutrophil/lymphocyte ratio (2.0 ± 0.7 vs 2.7 ± 1.2; p = 0.003). The Cox mortality model did not show a statistical significance influence of IL-6 assessed during the follow-up.

Conclusion

There was a progressive increase in IL-6 during the follow-up, however, without influence on mortality.

CONQUEST Quality Standards: For the Collaboration on Quality Improvement Initiative for Achieving Excellence in Standards of COPD Care

Background

Chronic obstructive pulmonary disease (COPD) are managed predominantly in primary care. However, key opportunities to optimize treatment are often not realized due to unrecognized disease and delayed implementation of appropriate interventions for both diagnosed and undiagnosed individuals. The COllaboratioN on QUality improvement initiative for achieving Excellence in STandards of COPD care (CONQUEST) is the first-of-its-kind, collaborative, interventional COPD registry. It comprises an integrated quality improvement program focusing on patients (diagnosed and undiagnosed) at a modifiable and higher risk of COPD exacerbations. The first step in CONQUEST was the development of quality standards (QS). The QS will be imbedded in routine primary and secondary care, and are designed to drive patient-centered, targeted, risk-based assessment and management optimization. Our aim is to provide an overview of the CONQUEST QS, including how they were developed, as well as the rationale for, and evidence to support, their inclusion in healthcare systems.

Methods

The QS were developed (between November 2019 and December 2020) by the CONQUEST Global Steering Committee, including 11 internationally recognized experts with a specialty and research focus in COPD. The process included an extensive literature review, generation of QS draft wording, three iterative rounds of review, and consensus.

Results

Four QS were developed: 1) identification of COPD target population, 2) assessment of disease and quantification of future risk, 3) non-pharmacological and pharmacological intervention, and 4) appropriate follow-up. Each QS is followed by a rationale statement and a summary of current guidelines and research evidence relating to the standard and its components.

Conclusion

The CONQUEST QS represent an important step in our aim to improve care for patients with COPD in primary and secondary care. They will help to transform the patient journey, by encouraging early intervention to identify, assess, optimally manage and followup COPD patients with modifiable high risk of future exacerbations.

Skeletal muscle is associated with exercise tolerance evaluated by cardiopulmonary exercise testing in Japanese patients with chronic obstructive pulmonary disease

Decreasing exercise tolerance is one of the key features related to a poor prognosis in patients with chronic obstructive pulmonary disease (COPD). Cardiopulmonary exercise testing (CPET) is useful for evaluating exercise tolerance. The present study was performed to clarify the correlation between exercise tolerance and clinical parameters, focusing especially on the cross-sectional area (CSA) of skeletal muscle. The present study investigated 69 patients with COPD who underwent CPET. The correlations between oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\dot{\text{V}} \text{O}}}_{2}$$\end{document}V˙O2) at peak exercise and clinical parameters of COPD, including skeletal muscle area measured using single-section axial computed tomography (CT), were evaluated. The COPD assessment test score (ρ = − 0.35, p = 0.02) was weakly correlated with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\dot{\text{V}} \text{O}}}_{2}$$\end{document}V˙O2 at peak exercise. In addition, forced expiratory volume in one second (FEV₁) (ρ = 0.39, p = 0.0009), FEV₁/forced vital capacity (ρ = 0.33, p = 0.006), and the CSA of the pectoralis muscles (PMs) (ρ = 0.36, p = 0.007) and erector spinae muscles (ECMs) (ρ = 0.39, p = 0.003) were correlated with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\dot{\text{V}} \text{O}}}_{2}$$\end{document}V˙O2 at peak exercise. Multivariate analysis adjusted by age and FEV₁ indicated that PM_CSA was weakly correlated after adjustment (β value [95% confidence interval] 0.175 [0.03–0.319], p = 0.02). In addition, ECM_CSA tended to be correlated, but not significantly after adjustment (0.192 [− 0.001–0.385] p = 0.052). The COPD assessment test, FEV₁, FEV₁/FVC, PM_CSA, and ECM_CSA were significantly correlated with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\dot{\text{V}} \text{O}}}_{2}$$\end{document}V˙O2 at peak exercise.

Treatment of critically ill patients with acute hypercarbic respiratory failure by average volume-assured pressure support mode

OBJECTIVES

Average volume-assured pressure support (AVAPS), a dual mode, delivers a set tidal volume (TV) per kg by adjusting the pressure between upper and lower inspiratory positive airway pressures (IPAP). Thus, ventilation is presumed to be happened effectively by sending a guaranteed TV. This study was aimed to evaluate the effectiveness of AVAPS mode in critically ill patients with acute hypercarbic respiratory failure (HRF) and compare the results with bilevel positive airway pressure-spontaneous/timed (BPAP-S/T) mode.

METHODS

Sixty patients were assigned to BPAP-S/T (n = 29) and AVAPS modes (n = 31). Maximum IPAP was started at 20 cmH₂ O and minimum IPAP was set at 5 cmH₂ O higher than expiratory positive airway pressure (EPAP) in AVAPS mode. IPAP was started at 15 cmH₂ O in BPAP-S/T mode. IPAP levels were titrated up to 30 cmH₂ O during noninvasive mechanic ventilation (NIMV) with a targeted TV of 6-8 mL/kg. Patients were followed for 5 days.

RESULTS

No differences were found in pH, paCO₂ , HCO₃ , TV and EPAP between the two groups when compared separately by days. Maximum IPAP levels were significantly high in AVAPS mode in all times (P < 0.001). The length of stay (LOS) in intensive care unit (ICU) (P = 0.994) and hospital (P = 0.509), hours of NIMV use per day (P = 0.101) and NIMV success rate (P = 0.931) were identical between the two groups. ICU (P = 0.931), hospital (P = 0.800), 6-month (P = 0.919) and 1-year (P = 0.645) mortality rates were also not different between the both groups.

CONCLUSIONS

AVAPS mode had similar efficiency with BPAP-S/T mode regarding the NIMV treatment success in critically ill patients with acute HRF.

Peripheral Blood Eosinophils and Nine Years Mortality in COPD Patients

BACKGROUND

Eosinophil counts increase during chronic obstructive pulmonary disease (COPD) exacerbation and influence the response to different agents (such as inhaled and systemic corticosteroids), as well as increase the production of other inflammatory cytokines. However, few studies have evaluated the association between peripheral blood eosinophils with mortality rate.

OBJECTIVE

To evaluate the association between peripheral blood eosinophils and mortality rate in COPD patients over a nine-year period.

STUDY DESIGN AND METHODS

This cohort included 133 COPD patients assessed at baseline by spirometry, pulse oximetry (SpO2), complete blood count, body composition, dyspnea intensity [Modified Medical Research Council (mMRC)] and the six-minute distance test (6MWD). The Kaplan-Meier curve followed by a Log rank test was used to evaluate mortality rate related to eosinophil cutoff point categorization. Multivariate Cox regression analysis was performed to identify the association between eosinophils and mortality with all subjects evaluated at baseline, adjusted for age, gender, mMRC, 6MWT, forced expiratory volume in the first second (FEV1) and SpO2.

RESULTS

Nineteen patients did not complete follow-up and it was not possible to identify the date of death in four others. Therefore, 110 patients were included in the analysis. At baseline, 81% presented ≥150 eosinophil cells and 72% presented ≥2%. We identified a three-fold higher risk of death in those with <2% eosinophils and <150 cells. We did not identify statistical differences when using other cutoff points.

CONCLUSION

The decrease in number of peripheral eosinophils, with cutoff points at 2% and 150 cells, may be associated with a higher risk of death in COPD patients over nine years.

Short-Term Versus Long-Term Systemic Corticosteroid Use in the Acute Exacerbation of Chronic Obstructive Pulmonary Disease Patients

Background

The administration of systemic corticosteroids in chronic obstructive pulmonary disease (COPD) exacerbation is the first line of management. The duration of this administration, however, is not well established in clinical practice. The objective of this study is to compare the clinical outcomes between short-term and long-term corticosteroid use in the acute exacerbation of COPD patients.

Methods

A single-centre, retrospective cohort study was conducted. From 2014 to 2018, all patients over 40 years old with COPD who were admitted to the hospital with a case of COPD exacerbation and received systemic corticosteroids at presentation were included. The subjects were divided into two groups according to the duration of systemic corticosteroid therapy. The primary outcome was hospital re-admission within 180 days. The secondary outcomes were 30 days mortality and length of hospitalisation. The two groups were compared using an independent sample t-test, a Chi-square test, and a Mann-Whitney U test, according to the data type.

Results

Eighty patients met the inclusion criteria. A total of 52 (65%) patients completed long-term therapy, while 28 (35%) patients were on short-term treatment. A total of 15 (28.8%) patients reached the primary endpoint in the long-term treatment group versus 19 (67.9%) in the short-term treatment group (P = 0.001). The 30-day mortality was 4 (7.7%) and 0 (0%), respectively, and the median length of hospitalisation was 6.5 and 7.5 days in the long-term group and short-term group, respectively (P = 0.32, P = 0.88).

Conclusion

Long-term corticosteroid use in the management of acute COPD exacerbation was significantly associated with fewer 180 days re-admission. The duration of corticosteroid use remains controversial, and further studies are recommended to assess the relationship between patient profile and adherence to therapy post-discharge with re-exacerbation.

Low Muscle Mass Is a Predictor of Malnutrition and Prolonged Hospital Stay in Patients With Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Longitudinal Study

BACKGROUND

Malnutrition in chronic obstructive pulmonary disease (COPD) patients is more prevalent during times of exacerbation. Fat-free mass index (FFMI), calf circumference (CC), and adductor muscle pollicis thickness (AMPT) can be used to identify reduced muscle mass and have been found to be good predictors of clinical outcomes in other conditions, but they have not been investigated in COPD. Therefore, this study evaluated low muscle mass as predictor of malnutrition, prolonged length of stay (LOS), and in-hospital death in COPD patients.

METHODS

This prospective cohort study was carried out in hospitalized patients with COPD exacerbation. Malnutrition diagnosis was performed by Subjective Global Assessment, and muscle mass was assessed by FFMI, calculated using fat-free mass from bioelectrical impedance, CC, and AMPT. Clinical outcomes (LOS and in-hospital death) were collected from records.

RESULTS

One hundred seventy-six patients were included (68.2 ± 10.4 years old, 56.2% women); 74.2% were classified as Global Initiative of Chronic Obstructive Lung Disease 2 or 3 and 58.2% as malnourished. The median LOS was 11 (7-19) days, and the incidence of death was 9.1%. Low FFMI and CC predicted malnutrition (low CC: odds ratio [OR], 4.6; 95% CI, 2.2-9.7 and low FFMI: OR, 8.8; 95% CI, 3.7-20.8) and were associated with prolonged LOS (low CC: OR, 2.3; 95% CI, 1.1-4.6 and low FFMI: OR, 2.5; 95% CI, 1.3-4.8).

CONCLUSION

Simple, inexpensive, and noninvasive parameters of muscle mass-FFMI and CC-are good predictors of malnutrition and prolonged LOS in COPD patients experiencing exacerbation.

Hardware Prototype for Wrist-Worn Simultaneous Monitoring of Environmental, Behavioral, and Physiological Parameters

We designed a low-cost wrist-worn prototype for simultaneously measuring environmental, behavioral, and physiological domains of influencing factors in healthcare. Our prototype continuously monitors ambient elements (sound level, toxic gases, ultraviolet radiation, air pressure, temperature, and humidity), personal activity (motion tracking and body positioning using gyroscope, magnetometer, and accelerometer), and vital signs (skin temperature and heart rate). An innovative three-dimensional hardware, based on the multi-physical-layer approach is introduced. Using board-to-board connectors, several physical hardware layers are stacked on top of each other. All of these layers consist of integrated and/or add-on sensors to measure certain domain (environmental, behavioral, or physiological). The prototype includes centralized data processing, transmission, and visualization. Bi-directional communication is based on Bluetooth Low Energy (BLE) and can connect to smartphones as well as smart cars and smart homes for data analytic and adverse-event alerts. This study aims to develop a prototype for simultaneous monitoring of the all three areas for monitoring of workplaces and chronic obstructive pulmonary disease (COPD) patients with a concentration on technical development and validation rather than clinical investigation. We have implemented 6 prototypes which have been tested by 5 volunteers. We have asked the subjects to test the prototype in a daily routine in both indoor (workplaces and laboratories) and outdoor. We have not imposed any specific conditions for the tests. All presented data in this work are from the same prototype. Eleven sensors measure fifteen parameters from three domains. The prototype delivers the resolutions of 0.1 part per million (PPM) for air quality parameters, 1 dB, 1 index, and 1 °C for sound pressure level, UV, and skin temperature, respectively. The battery operates for 12.5 h under the maximum sampling rates of sensors without recharging. The final expense does not exceed 133€. We validated all layers and tested the entire device with a 75 min recording. The results show the appropriate functionalities of the prototype for further development and investigations.

Early Predictors of Mortality in Patients with COPD, in Relation to Respiratory and Non-Respiratory Causes of Death - A National Register Study

Background

Both single factors and composite measures have been suggested to predict mortality in patients with chronic obstructive pulmonary disease (COPD) and there is a need to analyze the relative importance of each variable.

Objective

To explore the predictors of mortality for patients with COPD in relation to respiratory, cardiac, and malignant causes, as well as all causes of death.

Methods

After merging the Swedish Respiratory Tract Register (SRTR) and the Swedish Cause of Death Register, patients with respiratory, cardiac, and other causes of death were identified. Demographic and clinical variables from the deceased patients’ first registration with the SRTR were compared. Three univariable and multivariable Cox proportional hazards regression analyses were conducted for different causes of death, with time from first registration to either death or a fixed end date as dependent variable, and variables regarding demographics, respiration, and comorbidities as independent variables.

Results

In the multivariable Cox models, mortality for patients with all causes of death was predicted by older age 1.79 (CI 1.41, 2.27), lower percentage of predicted forced expiratory volume in 1 second (FEV₁ %) 0.99 (CI 0.98, 0.99), lower saturation 0.92 (CI 0.86, 0.97), worse dyspnea 1.48 (CI 1.26, 1.74) (p<0.002 to p<0.001), less exercise 0.91 (CI 0.85, 0.98), and heart disease 1.53 (CI 1.06, 2.19) (both p<0.05). Mortality for patients with respiratory causes was predicted by higher age 1.67 (CI 1.05, 2.65) (p<0.05), lower FEV_1% 0.98 (CI 0.97, 0.99), worse dyspnea 2.05 (CI 1.45, 2.90), and a higher number of exacerbations 1.27 (CI 1.11, 1.45) (p<0.001 in all comparisons). For patients with cardiac causes of death, mortality was predicted by lower FEV_1% 0.99 (CI 0.98, 0.99) (p=0.001) and lower saturation 0.82 (CI 0.76, 0.89) (p<0.001), older age 1.46 (CI 1.02, 2.09) (p<0.05), and presence of heart disease at first registration 2.06 (CI 1.13, 3.73) (p<0.05).

Conclusion

Obstruction predicted mortality in all models and dyspnea in two models and needs to be addressed. Comorbidity with heart disease could further worsen the COPD patient’s prognosis and should be treated by a multidisciplinary team of professional specialists.

FEV1 is a stronger mortality predictor than FVC in patients with moderate COPD and with an increased risk for cardiovascular disease

Purpose

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death worldwide. Impaired lung function is associated with heightened risk for death, cardiovascular events, and COPD exacerbations. However, it is unclear if forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) differ in predictive value.

Patients and Methods

Data from 16,485 participants in the Study to Understand Mortality and Morbidity (SUMMIT) in COPD were analyzed. Patients were grouped into quintiles for each lung function parameter (FEV₁ %predicted, FVC %predicted, FEV₁/FVC). The four highest quintiles (Q2-Q5) were compared to the lowest (Q1) to assess their relationship with all-cause mortality, cardiovascular events, and moderate-to-severe and severe exacerbations. Cox-regression was used, adjusted for age, sex, ethnicity, body-mass index, smoking status, previous exacerbations, cardiovascular disease, treatment, and modified Medical Research Council dyspnea score.

Results

Compared to Q1 (<53.5% FEV₁ predicted), increasing FEV₁ quintiles (Q2 53.5-457.5% predicted, Q3 57.5-461.6% predicted, Q4 61.6-465.8% predicted, and Q5 ≥65.8%) were all associated with significantly decreased all-cause mortality (20% (4-34%), 28% (13-40%), 23% (7-36%), and 30% (15-42%) risk reduction, respectively). In contrast, a significant risk reduction (21% (4-35%)) was seen only between Q1 and Q5 quintiles of FVC. Neither FEV₁ nor FVC was associated with cardiovascular risk. Increased FEV₁ and FEV₁/FVC quintiles were also associated with the reduction of moderate-to-severe and severe exacerbations while, surprisingly, the highest FVC quintile was related to the heightened exacerbation risk (28% (8-52%) risk increase).

Conclusion

Our results suggest that FEV₁ is a stronger predictor for all-cause mortality than FVC in moderate COPD patients with heightened cardiovascular risk and that subjects with moderate COPD have very different risks.

Elevated blood eosinophils in acute COPD exacerbations: better short- and long-term prognosis

Background: Elevated eosinophils in COPD is recognized as a potential risk factor for exacerbations, but the prognostic role of elevated eosinophils during exacerbations of COPD is unclear. We investigated short-term and long-term outcomes in patients with exacerbations of eosinophilic phenotype, compared with patients with low blood eosinophils. Methods: A single-centre retrospective study of all patients admitted for a COPD exacerbation to Bispebjerg University Hospital in 2010-2011 was established by linking inpatient data with national patient and prescription registries, with a three-year follow-up period. Elevated eosinophils were defined as a blood eosinophil level at admission of ≥0.30 × 10⁹ cells/L. Results: A total of 811 patients were included; 13.2% had an eosinophilic exacerbation. The eosinophilic group had less need for non-invasive ventilation, shorter inpatient stay, and lower in-hospital mortality, compared to the non-eosinophilic group. However, the eosinophilic and non-eosinophilic groups showed similar risks of readmission (incidence rate ratio[95], 0.99 [0.73-1.36]). Three-year mortality was high in both groups, although lower in the eosinophilic group (40% vs. 54%, p = 0.006). Conclusions: COPD exacerbations in patients with high blood eosinophil have a better short-term prognosis without higher risk of subsequent exacerbation. Eosinophilic exacerbations have also a lower three-year mortality.

Comorbidity and thirty-day hospital readmission odds in chronic obstructive pulmonary disease: a comparison of the Charlson and Elixhauser comorbidity indices

Background

Readmissions following exacerbations of chronic obstructive pulmonary disease (COPD) are prevalent and costly. Multimorbidity is common in COPD and understanding how comorbidity influences readmission risk will enable health systems to manage these complex patients.

Objectives

We compared two commonly used comorbidity indices published by Charlson and Elixhauser regarding their ability to estimate readmission odds in COPD and determine which one provided a superior model.

Methods

We analyzed discharge records for COPD from the Nationwide Readmissions Database spanning 2010 to 2016. Inclusion and readmission criteria from the Hospital Readmissions Reduction Program were utilized. Elixhauser and Charlson Comorbidity Index scores were calculated from published methodology. A mixed-effects logistic regression model with random intercepts for hospital clusters was fit for each comorbidity index, including year, patient-level, and hospital-level covariates to estimate odds of thirty-day readmissions. Sensitivity analyses included testing age inclusion thresholds and model stability across time.

Results

In analysis of 1.6 million COPD discharges, readmission odds increased by 9% for each half standard deviation increase of Charlson Index scores and 13% per half standard deviation increase of Elixhauser Index scores. Model fit was slightly better for the Elixhauser Index using information criteria. Model parameters were stable in our sensitivity analyses.

Conclusions

Both comorbidity indices provide meaningful information in prediction readmission odds in COPD with slightly better model fit in the Elixhauser model. Incorporation of comorbidity information into risk prediction models and hospital discharge planning may be informative to mitigate readmissions.

Relationship between gender and survival in a real-life cohort of patients with COPD

Background

Although COPD affects both men and women, its prevalence is increasing more rapidly in women. Disease outcomes appear different among women with more frequent dyspnea and anxiety or depression but whether this translates into a different prognosis remains to be determined. Our aim was to assess whether the greater clinical impact of COPD in women was associated with differences in 3-year mortality rates.

Methods

In the French Initiatives BPCO real-world cohort, 177 women were matched up to 458 menon age (within 5-year intervals) and FEV₁ (within 5% predicted intervals). 3-year mortality rate and survival were analyzed. Univariate and multivariate logistic regression analyses were performed.

Results

For a given age and level of airflow obstruction, women with COPD had more severe dyspnea, lower BMI, and were more likely to exhibit anxiety. Nevertheless, three-year mortality rate was comparable among men and women, respectively 11.2 and 10.8%. In a multivariate model, the only factors significantly associated with mortality were dyspnea and malnutrition but not gender.

Conclusion

Although women with COPD experience higher levels of dyspnea and anxiety than men at comparable levels of age and FEV1, these differences do not translate into variations in 3-year mortality rates.

Trial registration

04–479.