BODE index and GOLD staging as predictors of 1-year exacerbation risk in chronic obstructive pulmonary disease

Assessment of the BODE Index and Its Association With Inflammatory Mediators in Chronic Obstructive Pulmonary Disease (COPD) Patients

Background Chronic obstructive pulmonary disease (COPD) is a respiratory condition impacting daily activities of susceptible individuals and increasing the risk of respiratory infections and cardiovascular disease. Body Mass Index, Airflow Obstruction, Dyspnea, and Exercise Capacity (BODE) index is applied clinically to measure the survival of COPD patients. Inflammatory mediators, including cytokines and chemokines, significantly contribute to the COPD pathology. In this study, the association between the BODE index and systemic inflammatory mediators in stable COPD patients was evaluated. Methodology This was a cross-sectional observational study performed on 85 clinically stable COPD patients and the GOLD criteria were used for the diagnosis. The demographics and clinical history of the patients were documented. The clinical assessment comprising the Modified Medical Research Council (MMRC) dyspnea scale, COPD Assessment Test (CAT) and BODE index was measured. The serum levels of systemic inflammatory mediators, tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP) and interleukin-6 (IL-6) were measured. The association between the BODE index and inflammatory markers was analyzed using Pearson's correlation analysis. Results The majority of patients (61.2%) were in stage I BODE index and BODE index showed a significant correlation with GOLD stage severity (p=0.001). The CRP, TNF-α and IL-6 levels were increased in BODE stage IV when compared to stage III, II and I (p=0.001). The CRP (r=0.654; p=0.000), TNF-α (0.542; p=0.01) and IL-6 (r=0.498; p=0.02) showed significant correlation with BODE index. Conclusion The evaluation of the BODE index alongside systemic inflammatory markers is crucial for enhancing the management of COPD and subsequently improving patient outcomes.

Left ventricular concentric remodeling in COPD patients: A cross-sectional observational study

OBJECTIVE

To investigate the association between left ventricular structure and disease severity in COPD patients.

METHODS

Twenty-eight COPD patients were stratified according to the disease severity, using the BODE index, into Lower (n=17) and Higher (n=11) groups, composed of patients with lower severity (BODE <5) and higher severity (BODE ≥5), respectively. Left ventricle (LV) was assessed by 2D-echocardiography. BODE index was calculated using body mass index (BMI); forced expiratory volume in the first second (FEV1, %); modified Medical Research Council (mMRC) and distance walked during 6-minute walk test (6MWD).

RESULTS

Patients in the Higher group showed lower oxygen arterial saturation (p=0.02), FEV1 (p<0.01) and 6MWD (p=0.02) and higher value of relative posterior wall thickness (RWT) compared to Lower group (p=0.02). There were significant associations between LV end-systolic diameter (LVESD) and BODE index (r=-0.38, p=0.04), LV end-diastolic diameter (LVEDD) and FEV1 (r=0.44, p=0.02), LVEDD and BMI (r=0.45, p=0.02), LVESD and BMI (r=0.54, p=0.003) and interventricular septal thickness and 6MWD (r=-0.39, p=0.04).

CONCLUSIONS

More severe COPD patients, BODE score ≥5, may have higher RWT, featuring a possible higher concentric remodeling of LV in this group. Besides that, a greater disease severity may be related to LV chamber size reduction.

Correlation of Body Mass Index and Oxygen Saturation in Chronic Obstructive Pulmonary Disease Patients at a Tertiary Care Center in Nepal: A Cross-Sectional Study

Purpose

Chronic obstructive pulmonary disease (COPD) is a major cause of mortality and morbidity worldwide. COPD is associated with clinically relevant pulmonary and extrapulmonary manifestations, including hypoxemia and weight loss. The correlation of body mass index (BMI) and oxygen saturation (SpO2) with COPD grades may provide a useful additional marker for understanding and managing the disease. The aim of the study was to study the correlation of BMI and oxygen saturation with COPD in patients presenting to a tertiary care center in Nepal.

Patients and Methods

A descriptive cross-sectional study was conducted among 145 COPD patients visiting the Department of Medicine in Shree Birendra Hospital between 1 March 2019 and 28 February 2020. A non-probability purposive sampling method was used and data were analyzed using SPSS version 21. A p-value of <0.05 was considered significant.

Results

Out of 145 COPD patients, 58 (40%) were underweight, 53 (36.55%) were of normal weight, 20 (13.79%) were overweight, and 14 (9.6%) were obese. The number of underweight patients was highest in COPD grade 4 and lowest in COPD grade 1. The proportion of subjects with underweight BMI and hypoxia increased with COPD severity, and both were statistically significant (p-values <0.01).

Conclusion

Our study shows that BMI and oxygen saturation have an inverse association with COPD severity. The correlation of BMI and oxygen saturation with COPD grade could provide a supplementary marker of disease severity, which could be useful in the understanding of the disease process and subsequent management of COPD.

Automatically Explaining Machine Learning Predictions on Severe Chronic Obstructive Pulmonary Disease Exacerbations: Retrospective Cohort Study

Background

Chronic obstructive pulmonary disease (COPD) is a major cause of death and places a heavy burden on health care. To optimize the allocation of precious preventive care management resources and improve the outcomes for high-risk patients with COPD, we recently built the most accurate model to date to predict severe COPD exacerbations, which need inpatient stays or emergency department visits, in the following 12 months. Our model is a machine learning model. As is the case with most machine learning models, our model does not explain its predictions, forming a barrier for clinical use. Previously, we designed a method to automatically provide rule-type explanations for machine learning predictions and suggest tailored interventions with no loss of model performance. This method has been tested before for asthma outcome prediction but not for COPD outcome prediction.

Objective

This study aims to assess the generalizability of our automatic explanation method for predicting severe COPD exacerbations.

Methods

The patient cohort included all patients with COPD who visited the University of Washington Medicine facilities between 2011 and 2019. In a secondary analysis of 43,576 data instances, we used our formerly developed automatic explanation method to automatically explain our model’s predictions and suggest tailored interventions.

Results

Our method explained the predictions for 97.1% (100/103) of the patients with COPD whom our model correctly predicted to have severe COPD exacerbations in the following 12 months and the predictions for 73.6% (134/182) of the patients with COPD who had ≥1 severe COPD exacerbation in the following 12 months.

Conclusions

Our automatic explanation method worked well for predicting severe COPD exacerbations. After further improving our method, we hope to use it to facilitate future clinical use of our model.

International Registered Report Identifier (IRRID)

RR2-10.2196/13783

Developing a Machine Learning Model to Predict Severe Chronic Obstructive Pulmonary Disease Exacerbations: Retrospective Cohort Study

Background

Chronic obstructive pulmonary disease (COPD) poses a large burden on health care. Severe COPD exacerbations require emergency department visits or inpatient stays, often cause an irreversible decline in lung function and health status, and account for 90.3% of the total medical cost related to COPD. Many severe COPD exacerbations are deemed preventable with appropriate outpatient care. Current models for predicting severe COPD exacerbations lack accuracy, making it difficult to effectively target patients at high risk for preventive care management to reduce severe COPD exacerbations and improve outcomes.

Objective

The aim of this study is to develop a more accurate model to predict severe COPD exacerbations.

Methods

We examined all patients with COPD who visited the University of Washington Medicine facilities between 2011 and 2019 and identified 278 candidate features. By performing secondary analysis on 43,576 University of Washington Medicine data instances from 2011 to 2019, we created a machine learning model to predict severe COPD exacerbations in the next year for patients with COPD.

Results

The final model had an area under the receiver operating characteristic curve of 0.866. When using the top 9.99% (752/7529) of the patients with the largest predicted risk to set the cutoff threshold for binary classification, the model gained an accuracy of 90.33% (6801/7529), a sensitivity of 56.6% (103/182), and a specificity of 91.17% (6698/7347).

Conclusions

Our model provided a more accurate prediction of severe COPD exacerbations in the next year compared with prior published models. After further improvement of its performance measures (eg, by adding features extracted from clinical notes), our model could be used in a decision support tool to guide the identification of patients with COPD and at high risk for care management to improve outcomes.

International Registered Report Identifier (IRRID)

RR2-10.2196/13783

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.

Correlation Between 2D Strain and Classic Echocardiographic Indices in the Diagnosis of Right Ventricular Dysfunction in COPD

Purpose

This study aims to define which of the right ventricular myocardial deformation indices best correlates with the classic echocardiographic measurements and indices of right ventricular (RV) dysfunction in patients with stable chronic obstructive pulmonary disease (COPD).

Patients and Methods

Ninety-one patients with stable COPD underwent clinical evaluation, spirometry, a 6-minute walk test, and echocardiographic examination. Patients were divided into two groups: “with RV dysfunction” (≥1 classic parameter) and “without RV dysfunction”. We used speckle tracking to estimate myocardial deformation. For all analyses, results were considered significant if p < 0.05.

Results

The mean age across all participants was 65 ± 9 years, with 53% (48/91) being male. Patients in the group with RV dysfunction were able to walk shorter distances and had higher estimated right ventricular systolic pressure (RVSP) and mean pulmonary arterial pressure (mPAP). The RV free wall longitudinal strain (RVFWLS) was the only deformation indices that showed a significant correlation with all classic measurements and indices in the diagnosis of RV dysfunction (Wald test, 10.24; p < 0.01; odds ratio, 1.61). In the ROC curve analysis, the absolute value <20% was the lowest cut-off point of this index for detection of RV dysfunction (AUC = 0.93, S: 95.8%, and E: 88%).

Conclusion

In COPD patients, RVFWLS is the myocardial deformation index that best correlates with classic echocardiographic parameters for the diagnosis of RV dysfunction using <20% as a cut-off point.

Using Computational Methods to Improve Integrated Disease Management for Asthma and Chronic Obstructive Pulmonary Disease: Protocol for a Secondary Analysis

Background

Asthma and chronic obstructive pulmonary disease (COPD) impose a heavy burden on health care. Approximately one-fourth of patients with asthma and patients with COPD are prone to exacerbations, which can be greatly reduced by preventive care via integrated disease management that has a limited service capacity. To do this well, a predictive model for proneness to exacerbation is required, but no such model exists. It would be suboptimal to build such models using the current model building approach for asthma and COPD, which has 2 gaps due to rarely factoring in temporal features showing early health changes and general directions. First, existing models for other asthma and COPD outcomes rarely use more advanced temporal features, such as the slope of the number of days to albuterol refill, and are inaccurate. Second, existing models seldom show the reason a patient is deemed high risk and the potential interventions to reduce the risk, making already occupied clinicians expend more time on chart review and overlook suitable interventions. Regular automatic explanation methods cannot deal with temporal data and address this issue well.

Objective

To enable more patients with asthma and patients with COPD to obtain suitable and timely care to avoid exacerbations, we aim to implement comprehensible computational methods to accurately predict proneness to exacerbation and recommend customized interventions.

Methods

We will use temporal features to accurately predict proneness to exacerbation, automatically find modifiable temporal risk factors for every high-risk patient, and assess the impact of actionable warnings on clinicians’ decisions to use integrated disease management to prevent proneness to exacerbation.

Results

We have obtained most of the clinical and administrative data of patients with asthma from 3 prominent American health care systems. We are retrieving other clinical and administrative data, mostly of patients with COPD, needed for the study. We intend to complete the study in 6 years.

Conclusions

Our results will help make asthma and COPD care more proactive, effective, and efficient, improving outcomes and saving resources.

International Registered Report Identifier (IRRID)

PRR1-10.2196/27065

Prognostic models for outcome prediction in patients with chronic obstructive pulmonary disease: systematic review and critical appraisal

OBJECTIVE

To map and assess prognostic models for outcome prediction in patients with chronic obstructive pulmonary disease (COPD).

DESIGN

Systematic review.

DATA SOURCES

PubMed until November 2018 and hand searched references from eligible articles.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Studies developing, validating, or updating a prediction model in COPD patients and focusing on any potential clinical outcome.

RESULTS

The systematic search yielded 228 eligible articles, describing the development of 408 prognostic models, the external validation of 38 models, and the validation of 20 prognostic models derived for diseases other than COPD. The 408 prognostic models were developed in three clinical settings: outpatients (n=239; 59%), patients admitted to hospital (n=155; 38%), and patients attending the emergency department (n=14; 3%). Among the 408 prognostic models, the most prevalent endpoints were mortality (n=209; 51%), risk for acute exacerbation of COPD (n=42; 10%), and risk for readmission after the index hospital admission (n=36; 9%). Overall, the most commonly used predictors were age (n=166; 41%), forced expiratory volume in one second (n=85; 21%), sex (n=74; 18%), body mass index (n=66; 16%), and smoking (n=65; 16%). Of the 408 prognostic models, 100 (25%) were internally validated and 91 (23%) examined the calibration of the developed model. For 286 (70%) models a model presentation was not available, and only 56 (14%) models were presented through the full equation. Model discrimination using the C statistic was available for 311 (76%) models. 38 models were externally validated, but in only 12 of these was the validation performed by a fully independent team. Only seven prognostic models with an overall low risk of bias according to PROBAST were identified. These models were ADO, B-AE-D, B-AE-D-C, extended ADO, updated ADO, updated BODE, and a model developed by Bertens et al. A meta-analysis of C statistics was performed for 12 prognostic models, and the summary estimates ranged from 0.611 to 0.769.

CONCLUSIONS

This study constitutes a detailed mapping and assessment of the prognostic models for outcome prediction in COPD patients. The findings indicate several methodological pitfalls in their development and a low rate of external validation. Future research should focus on the improvement of existing models through update and external validation, as well as the assessment of the safety, clinical effectiveness, and cost effectiveness of the application of these prognostic models in clinical practice through impact studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017069247.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION NUMBER

CRD42016052075.

Can the six-minute walk distance predict the occurrence of acute exacerbations of COPD in patients in Brazil?

Objective:

To evaluate whether a six-minute walk distance (6MWD) of < 80% of the predicted value can predict the occurrence of acute exacerbations of COPD in patients in Brazil over a 2-year period.

Methods:

This was a retrospective cross-sectional study involving 50 COPD patients in Brazil. At enrollment, anthropometric data were collected and patients were assessed for pulmonary function (by spirometry) and functional exercise capacity (by the 6MWD). The patients were subsequently divided into two groups: 6MWD ≤ 80% of predicted and 6MWD > 80% of predicted. The occurrence of acute exacerbations of COPD over 2 years was identified by analyzing medical records and contacting patients by telephone.

Results:

In the sample as a whole, there was moderate-to-severe airflow obstruction (mean FEV₁ = 41 ± 12% of predicted) and the mean 6MWD was 469 ± 60 m (86 ± 10% of predicted). Over the 2-year follow-up period, 25 patients (50%) experienced acute exacerbations of COPD. The Kaplan-Meier method showed that the patients in whom the 6MWD was ≤ 80% of predicted were more likely to have exacerbations than were those in whom the 6MWD was > 80% of predicted (p = 0.01), whereas the Cox regression model showed that the former were 2.6 times as likely to have an exacerbation over a 2-year period as were the latter (p = 0.02).

Conclusions:

In Brazil, the 6MWD can predict acute exacerbations of COPD over a 2-year period. The risk of experiencing an acute exacerbation of COPD within 2 years is more than twice as high in patients in whom the 6MWD is ≤ 80% of predicted.

The Ratio Serum Creatinine/Serum Cystatin C (a Surrogate Marker of Muscle Mass) as a Predictor of Hospitalization in Chronic Obstructive Pulmonary Disease Outpatients

BACKGROUND

In chronic obstructive pulmonary disease (COPD), low muscle mass has been associated with several clinical outcomes such as low exercise capacity, hospital admission, and mortality. The Sarcopenia Index (SI) is a novel way to estimate muscle mass based on the ratio of serum creatinine (produced exclusively by muscle)/cystatin C (produced by all nucleated body cells).

OBJECTIVES

This study aims to assess the SI in stable COPD outpatients, as compared with a healthy control group, to quantify its relationship with several important clinical features in COPD, and to study its potential usefulness to predict COPD exacerbations and hospital admissions.

METHODS

The SI was calculated in 18 healthy control subjects and 65 stable COPD outpatients were included in the study. Patients were prospectively followed for 1 year after being enrolled in the study.

RESULTS

COPD patients had a lower SI than controls, that is lower muscle mass. Furthermore, patients with a modified Medical Research Council dyspnea score ≥2, patients with a COPD Assessment Test score ≥10, and patients with a high risk of exacerbation had lower levels of SI compared with patients without these characteristics. SI correlated with FEV1 (r = 0.491, p < 0.001), the 6-min walking test (r = 0.560, p = 0.001), and the Fat-Free Mass Index (r = 0.431, p = 0.017). Univariate and multivariate Cox proportional risk analysis showed that a low SI is an independent predictor of hospital admission in COPD outpatients followed for 1 year (HR 5.16, p = 0.025).

CONCLUSIONS

The ratio serum creatinine/serum cystatin C correlates with several COPD characteristics, and it can be used to predict COPD hospitalization.

Rural Residence and Chronic Obstructive Pulmonary Disease Exacerbations. Analysis of the SPIROMICS Cohort

Rationale: Rural residence is associated with poor outcomes in several chronic diseases. The association between rural residence and chronic obstructive pulmonary disease (COPD) exacerbations remains unclear.Objectives: In this work, we sought to determine the independent association between rural residence and COPD-related outcomes, including COPD exacerbations, airflow obstruction, and symptom burden.Methods: A total of 1,684 SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study) participants with forced expiratory volume in 1 second/forced vital capacity < 0.70 had geocoding-defined rural-urban residence status determined (N = 204 rural and N = 1,480 urban). Univariate and multivariate logistic and negative binomial regressions were performed to assess the independent association between rurality and COPD outcomes, including exacerbations, lung function, and symptom burden. The primary exposure of interest was rural residence, determined by geocoding of the home address to the block level at the time of study enrollment. Additional covariates of interest included demographic and clinical characteristics, occupation, and occupational exposures. The primary outcome measures were exacerbations determined over a 1-year course after enrollment by quarterly telephone calls and at an annual research clinic visit. The odds ratio (OR) and incidence rate ratio (IRR) of exacerbations that required treatment with medications, including steroids or antibiotics (total exacerbations), and exacerbations leading to hospitalization (severe exacerbations) were determined after adjusting for relevant covariates.Results: Rural residence was independently associated with a 70% increase in the odds of total exacerbations (OR, 1.70 [95% confidence interval (CI), 1.13-2.56]; P = 0.012) and a 46% higher incidence rate of total exacerbations (IRR 1.46 [95% CI, 1.02-2.10]; P = 0.039). There was no association between rural residence and severe exacerbations. Agricultural occupation was independently associated with increased odds and incidence of total and severe exacerbations. Inclusion of agricultural occupation in the analysis attenuated the association between rural residence and the odds and incidence rate of total exacerbations (OR, 1.52 [95% CI, 1.00-2.32]; P = 0.05 and IRR 1.39 [95% CI, 0.97-1.99]; P = 0.07). There was no difference in symptoms or airflow obstruction between rural and urban participants.Conclusions: Rural residence is independently associated with increased odds and incidence of total, but not severe, COPD exacerbations. These associations are not fully explained by agriculture-related exposures, highlighting the need for future research into potential mechanisms of the increased risk of COPD exacerbations in the rural population.

Predictors of short-term LAMA ineffectiveness in treatment naïve patients with moderate to severe COPD

BACKGROUND

No specific (only subgroup) recommendations for the use of long-acting muscarinic antagonists in chronic obstructive pulmonary disease (COPD) exist. The aim of this exploratory hypothesis generating study was to assess whether different phenotypic/endotypic characteristics could be determinants of the short-term ineffectiveness of the initial tiotropium bromide monotherapy in treatment naïve moderate to severe COPD patients.

METHODS

A total of 51 consecutively recruited COPD patients were followed for 3 months after the initial evaluation and prescribed initial treatment (tiotropium). Short-term treatment ineffectiveness was assessed as a composite measure comprising COPD exacerbations, need for additional treatment, and no improvement in functional parameters, e.g. 6‑min walking test (6MWT), body-mass index, airflow obstruction, dyspnea, and exercise (BODE) index and forced expiratory volume in 1 s (FEV₁), and as single components.

RESULTS

Treatment ineffectiveness was significantly associated with baseline hemoglobin level, COPD assessment test (CAT) score, modified Medical Research Council (mMRC) scale and BODE index (p = 0.002). Incident exacerbation during the follow-up was associated with baseline bronchoalveolar lavage fluid (BALF) alpha-amylase level and CAT score (p < 0.001), and change in treatment with leukocyte count, 6MWT desaturation and fatigue (p < 0.001). No improvement in 6MWT was associated with baseline CAT score, body mass index, mMRC, fatigue, 6MWT and BODE index (p = 0.002). No improvement in BODE index was associated with leukocyte count, serum interleukin 8 (IL-8) and BALF albumin levels (p < 0.001); and no improvement in FEV₁ with CAT score, baseline vital capacity and BALF tumor necrosis factor alpha (TNF-alpha) level (p < 0.001).

CONCLUSION

Our results suggest that there is a possibility to identify predictors of short-term tiotropium ineffectiveness in patients with moderate to severe COPD.

Clinical and pulmonary functions profiling of patients with chronic obstructive pulmonary disease experiencing frequent acute exacerbations

Purpose:

The present study aimed at clinical and pulmonary functions profiling of patients with chronic obstructive pulmonary disease (COPD) to anticipate future exacerbations.

Methods:

The study included 80 COPD patients; 40 patients had ≥2 acute exacerbations during preceding 1 year (frequent exacerbation [FECOPD] group) and 40 patients had <2 acute exacerbations during preceding 1 year (infrequent exacerbation [I-FECOPD] group). Clinical profile, sputum microbiology, blood gas analysis, spirometric indices, and diffusion capacity (transfer test) variables were assessed. Groups’ comparison was performed using an independent t-test for numeric scale parameters and Chi-square test for nominal parameters. Pearson's and Spearman's correlation coefficients were derived for numeric scale parameters and numeric nominal parameters, respectively. Multinomial logistic regression analysis was done using SPSS software.

Results:

FECOPD group contained younger patients than in I-FECOPD group although the difference was not statistically significant. There was no significant difference between two groups regarding smoking pack-years and duration of illness. FECOPD group had significantly more expectoration score and Modified Medical Research Council dyspnea scores. Cough score and wheeze score did not differ significantly between two groups. More patients in FECOPD group (12/40 vs. 4/40) had lower airway bacterial colonization. Arterial blood gas parameters were more deranged in FECOPD group. Spirometric indices (forced expiratory volume during 1^st s) as well as transfer test (both diffusing capacity for carbon monoxide and transfer coefficient of the lung values) were significantly reduced in FECOPD group.

Conclusions:

The patients in FECOPD group had clinical, spirometric, and transfer test profiling suggestive of a severe COPD phenotype, the recognition will help in predicting future exacerbations and a better management.

Impact and prevention of severe exacerbations of COPD: a review of the evidence

Severe exacerbations of COPD, ie, those leading to hospitalization, have profound clinical implications for patients and significant economic consequences for society. The prevalence and burden of severe COPD exacerbations remain high, despite recognition of the importance of exacerbation prevention and the availability of new treatment options. Severe COPD exacerbations are associated with high mortality, have negative impact on quality of life, are linked to cardiovascular complications, and are a significant burden on the health-care system. This review identified risk factors that contribute to the development of severe exacerbations, treatment options (bronchodilators, antibiotics, corticosteroids [CSs], oxygen therapy, and ventilator support) to manage severe exacerbations, and strategies to prevent readmission to hospital. Risk factors that are amenable to change have been highlighted. A number of bronchodilators have demonstrated successful reduction in risk of severe exacerbations, including long-acting muscarinic antagonist or long-acting β2-agonist mono- or combination therapies, in addition to vaccination, mucolytic and antibiotic therapy, and nonpharmacological interventions, such as pulmonary rehabilitation. Recognition of the importance of severe exacerbations is an essential step in improving outcomes for patients with COPD. Evidence-based approaches to prevent and manage severe exacerbations should be implemented as part of targeted strategies for disease management.

Inverse relationship between nonadherence to original GOLD treatment guidelines and exacerbations of COPD

Background

Prescriber disagreement is among the reasons for poor adherence to COPD treatment guidelines; it is yet not clear whether this leads to adverse outcomes. We tested whether undertreatment according to the original Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines led to increased exacerbations.

Methods

Records of 878 patients with spirometrically confirmed COPD who were followed from 2005 to 2010 at one Veterans Administration (VA) Medical Center were analyzed. Analysis of variance was performed to assess differences in exacerbation rates between severity groups. Logistic regression analysis was performed to assess the relationship between noncompliance with guidelines and exacerbation rates.

Findings

About 19% were appropriately treated by guidelines; 14% overtreated, 44% under-treated, and in 23% treatment did not follow any guideline. Logistic regression revealed a strong inverse relationship between undertreatment and exacerbation rate when severity of obstruction was held constant. Exacerbations per year by GOLD stage were significantly different from each other: mild 0.15, moderate 0.27, severe 0.38, very severe 0.72, and substantially fewer than previously reported.

Interpretation

The guidelines were largely not followed. Undertreatment predominated but, contrary to expectations, was associated with fewer exacerbations. Thus, clinicians were likely advancing therapy primarily based upon exacerbation rates as was subsequently recommended in revised GOLD and other more recent guidelines. In retrospect, a substantial lack of prescriber adherence to treatment guidelines may have been a signal that they required re-evaluation. This is likely to be a general principle regarding therapeutic guidelines. The identification of fewer exacerbations in this cohort than has been generally reported probably reflects the comprehensive nature of the VA system, which is more likely to identify relatively asymptomatic (ie, nonexacerbating) COPD patients. Accordingly, these rates may better reflect those in the general population. In addition, the lower rates may reflect the more complete preventive care provided by the VA.

Prediction models for exacerbations in patients with COPD

Personalised medicine aims to tailor medical decisions to the individual patient. A possible approach is to stratify patients according to the risk of adverse outcomes such as exacerbations in chronic obstructive pulmonary disease (COPD). Risk-stratified approaches are particularly attractive for drugs like inhaled corticosteroids or phosphodiesterase-4 inhibitors that reduce exacerbations but are associated with harms. However, it is currently not clear which models are best to predict exacerbations in patients with COPD. Therefore, our aim was to identify and critically appraise studies on models that predict exacerbations in COPD patients. Out of 1382 studies, 25 studies with 27 prediction models were included. The prediction models showed great heterogeneity in terms of number and type of predictors, time horizon, statistical methods and measures of prediction model performance. Only two out of 25 studies validated the developed model, and only one out of 27 models provided estimates of individual exacerbation risk, only three out of 27 prediction models used high-quality statistical approaches for model development and evaluation. Overall, none of the existing models fulfilled the requirements for risk-stratified treatment to personalise COPD care. A more harmonised approach to develop and validate high- quality prediction models is needed to move personalised COPD medicine forward.

Risk of exacerbations in COPD and asthma patients living in the neighbourhood of livestock farms: Observational study using longitudinal data

OBJECTIVE

Living in an area with a high density of livestock farms has been associated with adverse respiratory health effects in some studies. As patients with COPD and asthma already have a compromised respiratory function and chronic airway inflammation, they are expected to be at increased risk for adverse respiratory health effects. The objective of this study was to assess the association between livestock exposure and exacerbations in COPD and asthma.

METHODS

899 COPD and 2546 asthma patients from 15 general practices in a rural area with a high livestock density and 933 COPD and 2310 asthma patients from 15 practices in a control area in the Netherlands were included. Occurrence of exacerbations was based on the pharmaceutical treatment of exacerbations in COPD and asthma patients using 2006-2012 prescription data of electronic medical records. Farm exposure was assessed by comparing the study area with the control area, and with individual exposure estimates in the study area using Geographic Information System data.

RESULTS

The exacerbation rate was higher in the study area compared with the control area in COPD (IRR: 1.28; 95%CI: 1.06-1.55), but not in asthma patients (IRR: 0.87; 95%CI: 0.72-1.05). In general, individual exposure estimates in the study area were not associated with exacerbations. COPD patients living within a 500m radius of up to12,499 chickens had a 36% higher exacerbation rate (IRR: 1.36; 95%CI: 1.03-1.79).

CONCLUSIONS

Living in an area with a high livestock density is a risk factor for exacerbations in COPD patients. The environmental exposure responsible for this increased risk remains to be elucidated.

Predicting frequent COPD exacerbations using primary care data

PURPOSE

Acute COPD exacerbations account for much of the rising disability and costs associated with COPD, but data on predictive risk factors are limited. The goal of the current study was to develop a robust, clinically based model to predict frequent exacerbation risk.

PATIENTS AND METHODS

Patients identified from the Optimum Patient Care Research Database (OPCRD) with a diagnostic code for COPD and a forced expiratory volume in 1 second/forced vital capacity ratio <0.7 were included in this historical follow-up study if they were ≥40 years old and had data encompassing the year before (predictor year) and year after (outcome year) study index date. The data set contained potential risk factors including demographic, clinical, and comorbid variables. Following univariable analysis, predictors of two or more exacerbations were fed into a stepwise multivariable logistic regression. Sensitivity analyses were conducted for subpopulations of patients without any asthma diagnosis ever and those with questionnaire data on symptoms and smoking pack-years. The full predictive model was validated against 1 year of prospective OPCRD data.

RESULTS

The full data set contained 16,565 patients (53% male, median age 70 years), including 9,393 patients without any recorded asthma and 3,713 patients with questionnaire data. The full model retained eleven variables that significantly predicted two or more exacerbations, of which the number of exacerbations in the preceding year had the strongest association; others included height, age, forced expiratory volume in 1 second, and several comorbid conditions. Significant predictors not previously identified included eosinophilia and COPD Assessment Test score. The predictive ability of the full model (C statistic 0.751) changed little when applied to the validation data set (n=2,713; C statistic 0.735). Results of the sensitivity analyses supported the main findings.

CONCLUSION

Patients at risk of exacerbation can be identified from routinely available, computerized primary care data. Further study is needed to validate the model in other patient populations.

Evaluation of Left Ventricular Function and its Relationship With Multidimensional Grading System (BODE Index) in Patients With COPD

Cardiovascular disease (CVD) is one of the main causes of morbidity and mortality in chronic obstructive pulmonary disease (COPD) patients however data regarding left ventricle (LV) function in COPD is limited. We, in this study, aimed to evaluate the LV systolic function and its relation to BODE index in COPD patients with the utility of two-dimensional speckle tracking echocardiography (2D-STE). The study involved 125 COPD patients and 30 control subjects. All patients underwent 2D-echocardiography, pulmonary function tests and -minute walk tests. The patients were divided into four quartiles according to BODE index score. COPD patients had lower mitral annulus systolic velocity (Sm), average global longitudinal strain (GLS), average global longitudinal strain rate systolic (GLSRs), average GLSR early diastolic (GLSRe), average GLSR late diastolic (GLSRa), tricuspid annular plane systolic excursion (TAPSE) and peak systolic myocardial velocity (Sm-RV) (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001 and p = 0.002 respectively) than control subjects. There were significant differences between BODE index quartiles in terms of Sm, average GLS and average GLSRs. Patients were divided into two groups according to median value of GLS (> -18.6 and ≤ -18.6). BODE index quartiles were found to be independent predictors of decreased GLS in multivariate logistic regression analysis (p = 0.030). Increased BODE index was associated with impaired LV mechanics in patients with COPD.

An index of daily step count and systemic inflammation predicts clinical outcomes in chronic obstructive pulmonary disease

BACKGROUND

Identification of persons with chronic obstructive pulmonary disease (COPD) at risk for acute exacerbations (AEs) targets them for close monitoring.

OBJECTIVES

We examined the ability of a novel index combining physical activity and systemic inflammation to identify persons at risk for AEs.

METHODS

In an observational cohort study of 167 persons with COPD, we assessed daily step count, a direct measure of physical activity, with the StepWatch Activity Monitor and measured plasma C-reactive protein (CRP) and IL-6 levels. AEs and COPD-related hospitalizations were assessed prospectively over a median of 16 months. Predictors of AEs and COPD-related hospitalizations were assessed using negative binomial models.

MEASUREMENTS AND MAIN RESULTS

Median daily step count was 5,203 steps (interquartile range, 3,627-7,024). Subjects with daily step count ≤ 5,203 and CRP > 3 mg/l had an increased rate of AEs (rate ratio [RR], 2.06; 95% confidence interval [CI], 1.30-3.27) and COPD-related hospitalizations (RR, 3.51; 95% CI, 1.73-7.11) compared with subjects with daily step count > 5,203 and CRP ≤ 3 mg/l, adjusting for FEV1% predicted and prednisone use for AE in the previous year. Similarly, subjects with daily step count ≤ 5,203 and IL-6 > 2 pg/ml had an increased rate of AEs (RR, 2.04; 95% CI, 1.14-3.63) and COPD-related hospitalizations (RR, 4.27; 95% CI, 1.56-11.7) compared with subjects with daily step count > 5,203 and IL-6 ≤ 2 pg/ml.

CONCLUSIONS

An index combining daily step count and systemic inflammation can predict AEs and COPD-related hospitalizations. A validation study in a separate cohort is needed to confirm the utility of the proposed index as a clinical tool to risk stratify persons with COPD.

Prevention of Exacerbations in Chronic Obstructive Pulmonary Disease: Knowns and Unknowns

The 2011 recommendations of the Global initiative for chronic Obstructive Lung Disease (GOLD) constituted a major paradigm shift in COPD management since they set 2 major goals for the assessment and management of patients: (1) the reduction of their current level of symptoms (i.e., treat the patient today); and (2) the reduction of their risk of exacerbations (i.e., prevent them tomorrow). Exacerbations are not only an important clinical endpoint in patients with COPD, but they are also a risk factor themselves for additional adverse outcomes since they have been shown to increase the risk for mortality, to accelerate the decline in pulmonary function, and to decrease health status and quality of life. Despite their importance, many unanswered questions related to exacerbations remain. The purpose of this review is to discuss: (1)knowns and unknowns in our current understanding of exacerbations, (2) what known factors increase their risk, and (3) how to best prevent them.

Correlation of BMI and oxygen saturation in stable COPD in Northern India

Background:

Chronic obstructive pulmonary disease (COPD) is associated with clinically relevant extra pulmonary manifestations; one of them is weight loss. However, there are very few studies from North India available in relation to body mass index (BMI) and Oxygen saturation (SpO₂) with COPD.

Aims:

To study the prevalence of undernutrition among stable COPD patients and correlation of COPD severity with SpO₂ and BMI.

Settings and Design:

A prospective study was carried out at a tertiary care hospital.

Subjects and Methods:

COPD patients were diagnosed and staged as per global initiative for chronic obstructive lung disease (GOLD) guidelines. SpO₂ was measured using pulse oxymeter and BMI categorization was done as per new classification for Asian Indians (2009). Statistical analysis was done using Statistical Package for Social Sciences Version 15.0.

Results:

Out of 147 COPD patients, 85 (57.8%) were undernourished. The prevalence of undernourished BMI was 25%, 50.8%, 61.7%, and 80% in stage I, II, III and IV respectively; statistically significant (P < 0.050). The mean SpO₂ was 95.50 ± 1.41, 95.05 ± 2.42, 94.37 ± 2.28 and 93.05 ± 1.39 in stage I, II, III and IV respectively; statistically significant (F = 4.723; P = 0.004).

Conclusions:

The overall prevalence of under nutrition among COPD patients was 57.8%. With increasing COPD stage the BMI and median SpO₂ value decreased in progressive manner. Association of SpO₂ and COPD stages could be explored further in order to suggest an additional marker of disease severity that would add a new dimension in the management of COPD.

Oral Chinese herbal medicine combined with pharmacotherapy for stable COPD: a systematic review of effect on BODE index and six minute walk test

This systematic review evaluated the effects of Chinese herbal medicine (CHM) plus routine pharmacotherapy (RP) on the objective outcome measures BODE index, 6-minute walk test (6MWT), and 6-minute walk distance (6MWD) in individuals with stable chronic obstructive pulmonary disease (COPD). Searches were conducted of six English and Chinese databases (PubMed, EMBASE, CENTRAL, CINAHL, CNKI and CQVIP) from their inceptions until 18th November 2013 for randomized controlled trials involving oral administration of CHM plus RP compared to the same RP, with BODE Index and/or 6MWT/D as outcomes. Twenty-five studies were identified. BODE Index was used in nine studies and 6MWT/D was used in 22 studies. Methodological quality was assessed using the Cochrane Risk of Bias tool. Weaknesses were identified in most studies. Six studies were judged as 'low' risk of bias for randomisation sequence generation. Twenty-two studies involving 1,834 participants were included in the meta-analyses. The main meta-analysis results showed relative benefits for BODE Index in nine studies (mean difference [MD] -0.71, 95% confidence interval [CI] -0.94, -0.47) and 6MWT/D in 17 studies (MD 54.61 meters, 95%CI 33.30, 75.92) in favour of the CHM plus RP groups. The principal plants used were Astragalus membranaceus, Panax ginseng and Cordyceps sinensis. A. membranaceus was used in combination with other herbs in 18 formulae in 16 studies. Detailed sub-group and sensitivity analyses were conducted. Clinically meaningful benefits for BODE Index and 6MWT were found in multiple studies. These therapeutic effects were promising but need to be interpreted with caution due to variations in the CHMs and RPs used and methodological weakness in the studies. These issues should be addressed in future trials.

Pooled subpopulation analyses of the effects of roflumilast on exacerbations and lung function in COPD

BACKGROUND

This post-hoc analysis examined the impact of roflumilast on chronic obstructive pulmonary disease (COPD) exacerbations and lung function in patients with COPD who received concomitant long-acting β2-agonists (LABA) with or without prior inhaled corticosteroid (ICS) and the influence of various demographic and clinical characteristics on these outcomes.

METHODS

Data were pooled from 2 double-blind, placebo-controlled, 52-week studies of once-daily roflumilast 500 μg in patients with COPD. Endpoints were mean rate of exacerbations and change from baseline in pre- and postbronchodilator FEV1.

RESULTS

In this pooled analysis (N = 3091), addition of roflumilast to LABAs for 1 year in patients who discontinued ICS prior to study entry (n = 945) significantly reduced the risk of COPD exacerbations vs. placebo by 19.2% (p < 0.05) and significantly improved pre- and postbronchodilator FEV1 by 40 mL and 34 mL, respectively (both, p < 0.01). Similar improvements were observed in patients who received concomitant LABAs but were not taking ICS prior to study entry (n = 597). A significant reduction in COPD exacerbation risk with roflumilast vs. placebo was observed regardless of age or smoking status, and in patients who had severe or very severe COPD. Significantly improved lung function was observed with roflumilast in all the subgroups (p < 0.05), with the exception of patients with moderate COPD.

CONCLUSIONS

Roflumilast reduced exacerbation rates and improved lung function in patients with COPD who received concomitant LABA, regardless of prior ICS use, and across various patient subgroups regardless of age and smoking status.

CLINICALTRIALSGOV REGISTRATION NUMBERS

NCT00297102 (M2-124) and NCT00297115 (M2-125).

The COPD assessment test (CAT) assists prediction of COPD exacerbations in high-risk patients

We evaluated the predictive value of the COPD assessment test (CAT™) for exacerbation in the following six months or time to first exacerbation among COPD patients with previous exacerbations. COPD outpatients with a history of exacerbation from 19 hospitals completed the CAT questionnaire and spirometry over six months. Exacerbation events were prospectively collected using a structured questionnaire. The baseline CAT score categorised into four groups (0-9, 10-19, 20-29, and 30-40) showed strong prediction for time to first exacerbation and modest prediction for any exacerbation or moderate-severe exacerbation (AUC 0.83, 0.64, and 0.63 respectively). In multivariate analyses, the categorised CAT score independently predicted all three outcomes (p = 0.001 or p < 0.001). Compared with the lowest CAT score category, the higher categories were associated with significantly shorter time to first exacerbation and higher exacerbation risks. The corresponding adjusted median time was >24, 14, 9, and 5 weeks and the adjusted RR was 1.00, 1.30, 1.37, and 1.50 in the category of 0-9, 10-19, 20-29, and 30-40 respectively. Exacerbation history (≥2 vs. 1 event in the past year) was related to time to first exacerbation (adjusted HR 1.35; p = 0.023) and any exacerbation during the study period (adjusted RR 1.15; p = 0.016). The results of this study support the use of the CAT as a simple tool to assist in the identification of patients at increased risk of exacerbations. This could facilitate timely and cost-effective implementation of preventive interventions, and improve health resource allocation.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT01254032.

The health care burden of high grade chronic obstructive pulmonary disease in Korea: analysis of the Korean Health Insurance Review and Assessment Service data

BACKGROUND

Patients with high grade chronic pulmonary obstructive disease (COPD) account for much of the COPD-related mortality and incur excessive financial burdens and medical care utilization. We aimed to determine the characteristics and medical care use of such patients using nationwide data from the Korean Health Insurance Review and Assessment Service in 2009.

MATERIALS AND METHODS

Patients with COPD were identified by searching with the International Classification of Diseases-10th Revision for those using medication. Patients with high grade COPD were selected based on their patterns of tertiary institute visits and medication use.

RESULTS

The numbers of patients with high grade COPD increased rapidly in Korea during the study period, and they showed a high prevalence of comorbid disease. The total medical costs were over three times higher in patients with high grade COPD compared with those without it ($3,744 versus $1,183; P < 0.001). Medication costs comprised the largest portion of medical cost, but most impact came from hospitalization and exacerbation in both groups of patients. COPD grade and hospitalization in the previous year were the major factors affecting medical costs and days of utilizing health care resources.

CONCLUSION

Patients with high grade COPD impose a high economic burden on the health care system in Korea. Prevention of progression to high grade COPD is important, both clinically and economically.

Risk adjustment for health care financing in chronic disease: what are we missing by failing to account for disease severity?

BACKGROUND

Adjustment for differing risks among patients is usually incorporated into newer payment approaches, and current risk models rely on age, sex, and diagnosis codes. It is unknown the extent to which controlling additionally for disease severity improves cost prediction. Failure to adjust for within-disease variation may create incentives to avoid sicker patients. We address this issue among patients with chronic obstructive pulmonary disease (COPD).

METHODS

Cost and clinical data were collected prospectively from 1202 COPD patients at Kaiser Permanente. Baseline analysis included age, sex, and diagnosis codes (using the Diagnostic Cost Group Relative Risk Score) in a general linear model predicting total medical costs in the following year. We determined whether adding COPD severity measures-forced expiratory volume in 1 second, 6-Minute Walk Test, dyspnea score, body mass index, and BODE Index (composite of the other 4 measures)-improved predictions. Separately, we examined household income as a cost predictor.

RESULTS

Mean costs were $12,334/y. Controlling for Relative Risk Score, each ½ SD worsening in COPD severity factor was associated with $629 to $1135 in increased annual costs (all P<0.01). The lowest stratum of forced expiratory volume in 1 second (<30% normal) predicted $4098 (95% confidence interval, $576-$8773) additional costs. Household income predicted excess costs when added to the baseline model (P=0.038), but this became nonsignificant when also incorporating the BODE Index.

CONCLUSIONS

Disease severity measures explain significant cost variations beyond current risk models, and adding them to such models appears important to fairly compensate organizations that accept responsibility for sicker COPD patients. Appropriately controlling for disease severity also accounts for costs otherwise associated with lower socioeconomic status.

A comparison of three multidimensional indices of COPD severity as predictors of future exacerbations

BACKGROUND

Prediction of future exacerbations of chronic obstructive pulmonary disease (COPD) is a major concern for long-term management of this disease.

AIM

To determine which of three multidimensional assessment systems (the body mass index, obstruction, dyspnea, and exercise capacity [BODE] index; dyspnea, obstruction, smoking, exacerbations [DOSE] index; or age, dyspnea, obstruction [ADO] index) is superior for predicting exacerbations.

METHODS

This was a 2-year prospective cohort study of COPD patients. Pulmonary function tests, the 6-minute walk distance (6MWD), Modified Medical Respiratory Council (MMRC) dyspnea scores, chest computed-tomography measurements, and body composition were analyzed, and predictions of exacerbation by the three assessment systems were compared.

RESULTS

Among 183 patients who completed the study, the mean annual exacerbation rate was 0.57 events per patient year, which correlated significantly with lower predicted forced expiratory volume in 1 second (FEV1) (P < 0.001), lower transfer coefficient of the lung for carbon monoxide (%DLco/VA) (P = 0.021), lesser 6MWD (P = 0.016), higher MMRC dyspnea score (P = 0.001), higher DOSE index (P < 0.001), higher BODE index (P = 0.001), higher ADO index (P = 0.001), and greater extent of emphysema (P = 0.002). For prediction of exacerbation, the areas under the curves were larger for the DOSE index than for the BODE and ADO indices (P < 0.001). Adjusted multiple logistic regression identified the DOSE index as a significant predictor of risk of COPD exacerbation.

CONCLUSION

In this study, the DOSE index was a better predictor of exacerbations of COPD when compared with the BODE and ADO indices.

Daily step count predicts acute exacerbations in a US cohort with COPD

Background

COPD is characterized by variability in exercise capacity and physical activity (PA), and acute exacerbations (AEs). Little is known about the relationship between daily step count, a direct measure of PA, and the risk of AEs, including hospitalizations.

Methods

In an observational cohort study of 169 persons with COPD, we directly assessed PA with the StepWatch Activity Monitor, an ankle-worn accelerometer that measures daily step count. We also assessed exercise capacity with the 6-minute walk test (6MWT) and patient-reported PA with the St. George's Respiratory Questionnaire Activity Score (SGRQ-AS). AEs and COPD-related hospitalizations were assessed and validated prospectively over a median of 16 months.

Results

Mean daily step count was 5804±3141 steps. Over 209 person-years of observation, there were 263 AEs (incidence rate 1.3±1.6 per person-year) and 116 COPD-related hospitalizations (incidence rate 0.56±1.09 per person-year). Adjusting for FEV₁ % predicted and prednisone use for AE in previous year, for each 1000 fewer steps per day walked at baseline, there was an increased rate of AEs (rate ratio 1.07; 95%CI = 1.003–1.15) and COPD-related hospitalizations (rate ratio 1.24; 95%CI = 1.08–1.42). There was a significant linear trend of decreasing daily step count by quartiles and increasing rate ratios for AEs (P = 0.008) and COPD-related hospitalizations (P = 0.003). Each 30-meter decrease in 6MWT distance was associated with an increased rate ratio of 1.07 (95%CI = 1.01–1.14) for AEs and 1.18 (95%CI = 1.07–1.30) for COPD-related hospitalizations. Worsening of SGRQ-AS by 4 points was associated with an increased rate ratio of 1.05 (95%CI = 1.01–1.09) for AEs and 1.10 (95%CI = 1.02–1.17) for COPD-related hospitalizations.

Conclusions

Lower daily step count, lower 6MWT distance, and worse SGRQ-AS predict future AEs and COPD–related hospitalizations, independent of pulmonary function and previous AE history. These results support the importance of assessing PA in patients with COPD, and provide the rationale to promote PA as part of exacerbation-prevention strategies.

Association between periodontitis and chronic obstructive pulmonary disease in a Chinese population

BACKGROUND

A relationship between periodontitis and chronic respiratory disease has been suggested by recent studies. The aim of this study is to explore the association between periodontitis and chronic obstructive pulmonary disease (COPD) in a Chinese population.

METHODS

We conducted a case-control study of 581 COPD cases and 438 non-COPD controls. Lung function examination, a 6-minute walk test, and the British Medical Research Council questionnaire were performed. Periodontal clinical examination index included probing depth (PD), attachment loss (AL), bleeding index (BI), plaque index (PI), and alveolar bone loss. A validated index for predicting COPD prognosis, the body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index, was also calculated.

RESULTS

Participants with more severe COPD were more likely to have severe periodontal disease. PD, AL, PI, alveolar bone loss, and the number of teeth were significantly associated with all stages of COPD (all P <0.001). When compared to controls (BODE = 0), participants with higher BODE scores had significantly higher AL (P <0.001), BI (P = 0.027), PI (P <0.001), alveolar bone loss (P <0.001), and the number of teeth (P <0.001). PI appeared to be the main periodontal health-related factor for COPD, with an odds ratio (OR) = 9.01 (95% CI = 3.98 to 20.4) in the entire study population OR = 8.28 (95% CI = 2.36 to 29.0), OR = 5.89 (95% CI = 2.64 to 13.1), and OR = 2.46 (95% CI = 1.47 to 4.10) for current, smokers, and non-smokers, respectively.

CONCLUSION

Our study found a strong association between periodontitis and COPD, and PI seemed to be a major periodontal factor for predicting COPD among Chinese adults.

Oral hygiene, periodontal health and chronic obstructive pulmonary disease exacerbations

AIM

To assess the associations of oral hygiene and periodontal health with chronic obstructive pulmonary disease (COPD) exacerbations.

MATERIAL AND METHODS

In total, 392 COPD patients were divided into frequent and infrequent exacerbation (≥2 times and <2 times in last 12 months) groups. Their lung function and periodontal status were examined. Information on oral hygiene behaviours was obtained by interview.

RESULTS

In the univariate analysis, fewer remaining teeth, high plaque index (PLI) scores, low tooth brushing times, and low regular supra-gingival scaling were significantly associated with COPD exacerbations (all p-values <0.05). After adjustment for age, gender, body mass index, COPD severity and dyspnoea severity, the associations with fewer remaining teeth (p = 0.02), high PLI scores (p = 0.02) and low tooth brushing times (p = 0.008) remained statistically significant. When stratified by smoking, fewer remaining teeth (OR = 2.05, 95% CI: 1.04-4.02) and low tooth brushing times (OR = 4.90, 95% CI: 1.26-19.1) among past smokers and high PLI scores (OR = 3.43, 95% CI: 1.19-9.94) among never smokers were significantly associated with COPD exacerbations.

CONCLUSIONS

Fewer remaining teeth, high PLI scores, and low tooth brushing times are significant correlates of COPD exacerbations, indicating that improving periodontal health and oral hygiene may be a potentially preventive strategy against COPD exacerbations.

Clinical predictors of frequent exacerbations in subjects with severe chronic obstructive pulmonary disease (COPD)

BACKGROUND

Acute exacerbations are a significant source of morbidity and mortality associated with chronic obstructive pulmonary disease. Among individuals with COPD, some patients suffer an inordinate number of exacerbations while others remain relatively protected. We undertook a study to determine the clinical factors associated with "frequent exacerbator" status within a population of subjects with severe COPD.

METHODS

Case-control cohort recruited from two Boston-area practices. All subjects had GOLD stage 3 or 4 (FEV(1) ≤ 50% predicted) COPD. "Frequent exacerbators" (n = 192) had an average of ≥2 moderate-to-severe exacerbations per year while "non-exacerbators" (n = 153) had no exacerbations in the preceding 12 months. Multivariate logistic regression was performed to determine the significant clinical predictors of "frequent exacerbator" status.

RESULTS

Physician-diagnosed asthma was a significant predictor of frequent exacerbations. Within a subset of our cohort, the modified Medical Research Council dyspnea score and FEF (25-75%) predicted were also significant clinical predictors of frequent exacerbator status (p < 0.05). Differences in exacerbation frequency were not found to be due to increased current tobacco use or decreased rates of maintenance medication use.

CONCLUSIONS

Within our severe COPD cohort, a history of physician-diagnosed asthma was found to be a significant clinical predictor of frequent exacerbations. Although traditional risk factors such as decreased FEV(1)% predicted were not significantly associated with frequent exacerbator status, lower mid-expiratory flow rates, as assessed by FEF (25-75%) predicted, were significantly associated with frequent exacerbations in a subset of our cohort.

Modified BODE indexes: Agreement between multidimensional prognostic systems based on oxygen uptake

Aim

It has been recently shown that the original BODE index has a high degree of correlation with two modified BODE indexes using maximal oxygen uptake expressed either as mL/min/kg (mBODE) or as the percentage predicted (mBODE%). In this study we investigated the agreement between the two modified BODE indexes (mBODE and mBODE%) in patients with stable chronic obstructive pulmonary disease (COPD).

Methods

A total of 169 patients with stable COPD were enrolled in this cross-sectional study. Differences between the two mBODE indexes were assessed using kappa coefficients and Bland-Altman plots. One out of every three patients underwent the six-minute walking test to investigate the agreement with the original BODE index.

Results

Correlations between the two mBODE indexes with each other (r = 0.96, P < 0.001) and with the original BODE index (mBODE r = 0.88, P < 0.001; mBODE% r = 0.93, P < 0.001) were excellent. However, the two mBODE indexes were significantly different from each other (mBODE 5.27 ± 2.3 versus mBODE% 4.31 ± 2.5; P < 0.001). The kappa coefficients were significantly lower (entire study group k = 0.5, P < 0.001) for every GOLD stage. The mean difference between the two mBODE indexes was 0.8 ± 0.6 units. Differences with the original BODE were higher for the mBODE (1.8 ± 0.9) than for the mBODE% (0.6 ± 0.8).

Conclusions

The new mBODE indexes are highly correlated but significantly different from each other. The differences between the novel indexes deserve further scrutiny.