Validation of the i-BODE index as a predictor of hospitalization and mortality in patients with COPD participating in pulmonary rehabilitation

The effect of comprehensive multidisciplinary pulmonary rehabilitation on 5-year survival in COPD: does maintaining a home exercise program improve survival?

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) is one of the most common causes of death worldwide. Therefore, optimizing medical therapy in the comprehensive management of the disease, as well as including pulmonary rehabilitation (PR) in the treatment, is essential. The goal of our study was to determine the impact of PR on the survival of COPD patients.

METHODS

Between 2007-2015, 509 COPD patients who completed the PR constituted the PR group, while 167 patients who applied but could not complete it after the initial evaluations formed the control group. In the PR group, dyspnea perception, exercise capacity, muscle strength, body composition, quality of life, psychosocial status, and i-BODE scores were assessed at the beginning and end of the program, whereas in the control group, these assessments could only be conducted at the beginning. Also, after PR, our PR participants have prescribed a home exercise program, and they were recalled to the hospital at the 3rd, 6th, 12th, 18th, and 24th months for follow-up visits.

RESULTS

A statistically significant improvement was found in almost all the data (except FEV1/FVC, BORG after exercise, and FFMI) after PR. There was a statistically significant difference in 5-year survival in favor of the PR group (p = 0.006), and in PR patients who accompanied the home exercise program vs. those who did not (p = 0.000). Also the gains in MRC (p = 0.003; OR: 2.20; CI: 1.319- 3.682), MEP (p = 0.041; OR: 1.02; CI: 1.001-1.035), and i-BODE (p = 0.006; OR: 0.914; CI: 0.857-0.974) increased the survival.

DISCUSSION

Apart from incorporating PR into treatment in the comprehensive management of COPD, we demonstrated that maintaining a home exercise program for at least two years following PR increased 5-year survival significantly.

Clinical and Quality of Life Differences in Patients with COPD With and Without a Background of Hospitalization in the Last Year

Introduction:

Chronic Obstructive Pulmonary Disease (COPD) is the fourth leading cause of death worldwide. An upward trend is estimated by 2030. One of the causes of mortality is the exacerbations of symptoms that result in hospitalizations. These hospitalizations reduce the quality of life, limit performance in daily life, and increase the costs for the health system and the patient.

Objective:

This study aimed to determine the differences between hospitalized and non-hospitalized patients with a medical diagnosis of COPD, considering some sociodemographic and clinical variables, and survival rates.

Methods:

A cross-sectional study was conducted, which included patients diagnosed with COPD who initiated pulmonary rehabilitation (PR) from January to September 2018. The patients were divided into two groups: patients with one or more exacerbations that led to the hospitalization (COPD-H) and patients without hospitalizations in the last year (COPD-NH).

Results:

There were 128 participants (78 males and 50 females), with a mean age of 71.10±(9.34) in the COPD-H group and 71.30±(8.91) in the COPD-NH group. When comparing both groups, COPD-NH had a higher socioeconomic status (p=0.041), reporting a higher FEV1 44.71± (14.97), p=0.047, and comorbidities according to the COTE index (p<0.001).

Conclusion:

The patients with the highest number of hospitalizations belonged to a lower socioeconomic stratum and had a higher number of comorbidities. Therefore, it is necessary to identify these factors at the beginning of PR.

A Risk Prediction Model for Mortality Among Smokers in the COPDGene® Study

BACKGROUND

Risk factor identification is a proven strategy in advancing treatments and preventive therapy for many chronic conditions. Quantifying the impact of those risk factors on health outcomes can consolidate and focus efforts on individuals with specific high-risk profiles. Using multiple risk factors and longitudinal outcomes in 2 independent cohorts, we developed and validated a risk score model to predict mortality in current and former cigarette smokers.

METHODS

We obtained extensive data on current and former smokers from the COPD Genetic Epidemiology (COPDGene®) study at enrollment. Based on physician input and model goodness-of-fit measures, a subset of variables was selected to fit final Weibull survival models separately for men and women. Coefficients and predictors were translated into a point system, allowing for easy computation of mortality risk scores and probabilities. We then used the SubPopulations and InteRmediate Outcome Measures In COPD Study (SPIROMICS) cohort for external validation of our model.

RESULTS

Of 9867 COPDGene participants with standard baseline data, 17.6% died over 10 years of follow-up, and 9074 of these participants had the full set of baseline predictors (standard plus 6-minute walk distance and computed tomography variables) available for full model fits. The average age of participants in the cohort was 60 for both men and women, and the average predicted 10-year mortality risk was 18% for women and 25% for men. Model time-integrated area under the receiver operating characteristic curve statistics demonstrated good predictive model accuracy (0.797 average), validated in the external cohort (0.756 average). Risk of mortality was impacted most by 6-minute walk distance, forced expiratory volume in 1 second and age, for both men and women.

CONCLUSIONS

Current and former smokers exhibited a wide range of mortality risk over a 10- year period. Our models can identify higher risk individuals who can be targeted for interventions to reduce risk of mortality, for participants with or without chronic obstructive pulmonary disease (COPD) using current Global initiative for obstructive Lung Disease (GOLD) criteria.

Machine Learning and Prediction of All-Cause Mortality in COPD

BACKGROUND

COPD is a leading cause of mortality.

RESEARCH QUESTION

We hypothesized that applying machine learning to clinical and quantitative CT imaging features would improve mortality prediction in COPD.

STUDY DESIGN AND METHODS

We selected 30 clinical, spirometric, and imaging features as inputs for a random survival forest. We used top features in a Cox regression to create a machine learning mortality prediction (MLMP) in COPD model and also assessed the performance of other statistical and machine learning models. We trained the models in subjects with moderate to severe COPD from a subset of subjects in Genetic Epidemiology of COPD (COPDGene) and tested prediction performance in the remainder of individuals with moderate to severe COPD in COPDGene and Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE). We compared our model with the BMI, airflow obstruction, dyspnea, exercise capacity (BODE) index; BODE modifications; and the age, dyspnea, and airflow obstruction index.

RESULTS

We included 2,632 participants from COPDGene and 1,268 participants from ECLIPSE. The top predictors of mortality were 6-min walk distance, FEV1 % predicted, and age. The top imaging predictor was pulmonary artery-to-aorta ratio. The MLMP-COPD model resulted in a C index ≥ 0.7 in both COPDGene and ECLIPSE (6.4- and 7.2-year median follow-ups, respectively), significantly better than all tested mortality indexes (P < .05). The MLMP-COPD model had fewer predictors but similar performance to that of other models. The group with the highest BODE scores (7-10) had 64% mortality, whereas the highest mortality group defined by the MLMP-COPD model had 77% mortality (P = .012).

INTERPRETATION

An MLMP-COPD model outperformed four existing models for predicting all-cause mortality across two COPD cohorts. Performance of machine learning was similar to that of traditional statistical methods. The model is available online at: https://cdnm.shinyapps.io/cgmortalityapp/.

Novel Respiratory Disability Score Predicts COPD Exacerbations and Mortality in the SPIROMICS Cohort

Rationale

Some COPD patients develop extreme breathlessness, decreased exercise capacity and poor health status yet respiratory disability is poorly characterized as a distinct phenotype.

Objective

To define respiratory disability in COPD based on available functional measures and to determine associations with risk for exacerbations and death.

Methods

We analyzed baseline data from a multi-center observational study (SPIROMICS). This analysis includes 2332 participants (472 with severe COPD, 991 with mild/moderate COPD, 726 smokers without airflow obstruction and 143 non-smoking controls).

Measurements

We defined respiratory disability by ≥4 of 7 criteria: mMRC dyspnea scale ≥3; Veterans Specific Activity Questionnaire <5; 6-minute walking distance <250 m; St George’s Respiratory Questionnaire activity domain >60; COPD Assessment Test >20; fatigue (FACIT-F Trial Outcome Index) <50; SF-12 <20.

Results

Using these criteria, respiratory disability was identified in 315 (13.5%) participants (52.1% female). Frequencies were severe COPD 34.5%; mild-moderate COPD 11.2%; smokers without obstruction 5.2% and never-smokers 2.1%. Compared with others, participants with disability had more emphysema (13.2 vs. 6.6%) and air-trapping (37.0 vs. 21.6%) on HRCT (P<0.0001). Using principal components analysis to derive a disability score, two factors explained 71% of variance, and a cut point −1.0 reliably identified disability. This disability score independently predicted future exacerbations (ß=0.34; CI 0.12, 0.64; P=0.003) and death (HR 2.97; CI 1.54, 5.75; P=0.001). Thus, participants with disability by this criterion had almost three times greater mortality compared to those without disability.

Conclusion

Our novel SPIROMICS respiratory disability score in COPD was associated with worse airflow obstruction as well as airway wall thickening, lung parenchymal destruction and certain inflammatory biomarkers. The disability score also proved to be an independent predictor of future exacerbations and death. These findings validate disability as an important phenotype in the spectrum of COPD.

COPD: The Annual Cost-Of-Illness during the Last Two Decades in Italy, and Its Mortality Predictivity Power

Chronic obstructive pulmonary disease (COPD) is a progressive pathological condition characterized by a huge epidemiological and socioeconomic impact worldwide. In Italy, the actual annual cost of COPD was assessed for the first time in 2002: the mean cost per patient per year was €1801 and ranged from €1500 to €3912, depending on COPD severity. In 2008, the mean annual cost per patient was €2723.7, ranging from €1830.6 in mild COPD up to €5451.7 in severe COPD. In 2015, it was €3291, which is 20.8% and 82.7% higher compared to the costs estimated in 2008 and 2002, respectively. In all these studies, the major cost component was direct costs, in particular hospitalization costs due to exacerbations, which corresponded to 59.9% of the total cost and 67.2% of direct costs, respectively. When the annual healthcare expenditure per patient is related to the length of survival by means of the PRO-BODE Index (PBI, which is the implementation of the well-known BODE Index with costs due to annual exacerbations and/or hospitalizations), the annual cost of care proved much more strictly and inversely proportional to patients' survival at three years, with the highest regression coefficient (r = -0.58) of all the multidimensional indices presently available, including the BODE Index (r = -021). In Italy, even though tobacco smoking has progressively declined by up to 21% in the general population, the economic impact of COPD has shown relentless progression over the last two decades, confirming that the present national health system organization is still insufficient for facing the issue of chronic diseases, in particular COPD, effectively. The periodic assessment of costs is an effective instrument for care providers in predicting COPD mortality, and for decision makers for updating and planning their social, economic, and political strategies.

Predictors of mortality in patients with COPD after 9 years

Background

COPD is one of the leading causes of morbidity and mortality in the world; however, the most varied amounts of clinical and laboratory characteristics acts in different ways in the mortality among over time. Therefore, this study aimed to evaluate the predictors of mortality in patients with COPD after 9 years.

Patients and methods

One hundred and thirty-three patients with COPD were assessed at baseline by spirometry, pulse oximetry (SpO₂), body composition, intensity of dyspnea, distance walked in the 6-minute walk test (6MWT), and Charlson Comorbidity Index (CCI).

Results

After 9 years, it was not possible to identify the lifetime of 4 patients who died and of 19 patients who stopped follow-up; thus, 110 patients were included in the analysis of predictors of mortality (67% male, 65±9 years old, and FEV₁: 52.5 [40%–73%]). Male sex, age, SpO₂, Body mass index, airway Obstruction, Dyspnea, and Exercise capacity (BODE) index, and frequency of exacerbations in the first 3 years of follow-up were considered in the model. Patients classified at baseline with BODE class 2 (HR: 2.62, 95% CI: 1.36–5.04; P=0.004), BODE class 3 (HR: 2.54, 95% CI: 1.15–5.61; P=0.02), and BODE class 4 (HR: 15.35, 95% CI: 3.11–75.75; P=0.001) showed increased risk of death compared to those with BODE class 1. The CCI (HR: 1.29, 95% CI: 1.00–1.68; P=0.04) and the number of exacerbations in the first 3 years (HR: 1.32, 95% CI: 1.00–1.76; P=0.04) also showed increased risk of death. By replacing the BODE index for the variables that compose it, those with body mass index ≤21 kg/m² showed increased risk of death compared to those with body mass index (BMI)>21 kg/m² (HR: 2.70, 95% CI: 1.38–5.25; P=0.003).

Conclusion

After 9 years, we identified that those with high BODE index, greater CCI, greater frequency of exacerbations in the first 3 years, and BMI ≤21 kg/m² showed increased risk of death.

Including changes in dyspnea after inpatient rehabilitation improves prediction models of exacerbations in COPD

BACKGROUND

Reducing the probability of future exacerbations is one of the main goals of pulmonary rehabilitation (PR) in COPD. Recent studies identified predictors of future exacerbations. However, PR might alter both predictors and number of exacerbations.

OBJECTIVES

This secondary analysis examined which predictors assessed at both the beginning and the end of PR predict the risk of moderate (i.e. use of cortisone and/or antibiotics) and severe (hospitalization) exacerbations in the year after PR.

METHODS

A total of n = 383 COPD patients (34.7% female, mean age = 57.8 years (SD = 7.1), mean FEV1%pred = 51.0 (SD = 14.9)) who attended a 3-week inpatient PR were included. Number of moderate and severe exacerbations were assessed one year after PR (T2) via questionnaires. Potential predictors were assessed at the beginning (T0) and the end (T1) of PR. Negative binomial regression models were used.

RESULTS

The mean numbers of severe (M_s)/moderate (M_m) exacerbations in the year after PR (M_s,t2 = 0.19; M_{m, t2} = 1.07) was reduced compared to the numbers of exacerbations in the year before PR (M_s,t1 = 0.50, p < 0.001; M_m,t1 = 1.21, p = 0.051). Previous exacerbations, retirement, change in dyspnea (for severe exacerbations) and dyspnea at T1 (for moderate exacerbations) were identified as significant predictors.

CONCLUSIONS

PR might alter associations between predictors and future exacerbations. Dyspnea at the end of PR or change in dyspnea are better predictors than dyspnea at the beginning of PR.

Patient Related Outcomes-BODE (PRO-BODE): A composite index incorporating health utilization resources predicts mortality and economic cost of COPD in real life

Multidimensional scores were proposed for defining COPD outcomes, but without any incorporation of the economic COPD cost to clinical indices.

AIM

using mortality as an outcome, the hypothesis that adding total health care cost to the BODE index would better predict mortality in COPD was investigated.

METHODS

275 COPD patients were surveyed. Anthropometrics, lung function, the BODE and the Charlson Comorbidity Index were determined. History of exacerbations, ER visits, hospitalizations and mortality were also determined over the next three years, being their rates graded and added to the BODE index according to a simple algorithm. The novel PRO-BODE index ranged 0-10 points; its relationship to annual total COPD cost and survival was assessed by linear regression analysis.

RESULTS

total COD cost showed the highest relationship with survival (r = -0.58), even higher than that of age and of BODE index (r = -0.28 and r = -0.21, respectively). The integrated Pro-BODE score proved proportional to the cost of care and inversely proportional to the length of survival.

CONCLUSIONS

Pro-BODE is a novel composite index which helps in predicting in real life the impact of COPD over three years, both in terms of patients' survival and of COPD economic burden.

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.

Changes in BODE Quartiles After Pulmonary Rehabilitation Do Not Predict 2-Year Survival in Patients With COPD

PURPOSE

Pulmonary rehabilitation (PR) has well documented positive effects in patients with chronic obstructive pulmonary disease (COPD). The BODE (body mass index, airflow obstruction, dyspnea, and exercise) index reflects the multicomponent nature of COPD. We aimed to determine whether changes in BODE quartiles after a PR program might affect 2-year survival and which characteristics drive changes in BODE quartiles after PR intervention.

METHODS

Ninety-five patients with COPD participated in a PR program. The BODE index and anxiety, depression, and quality of life questionnaires were completed before and after the PR program. Five-year survival was recorded for all patients, irrespective of changes in BODE quartiles.

RESULTS

Up to 62% of patients with COPD had an improvement in the BODE index, whereas 42% of patients had a change in BODE quartile. Survival did not differ between patients who did not and who did show an improvement in BODE quartiles, despite a trend in favor of the latter (log-rank P = .202). Similar results were observed for patients who did and did not demonstrate a change in the BODE index ≥2 (log-rank P = .679). Significant changes in BODE quartiles were mainly attributed to the duration of the disease, current smoking status, hospitalization rate in the previous year, and the presence of poorer quality of life, as well as to anxiety and depression at baseline.

CONCLUSIONS

Pulmonary rehabilitation significantly influenced the BODE index. The significant changes in BODE quartiles were associated with the duration of the disease, current smoking status, increased hospitalization rate, poorer quality of life, anxiety, and depression at baseline, but failed to predict 2-year survival.

[Limitations of active therapeutic and palliative care in chronic respiratory disease]

The issue of intensive and palliative care in patients with chronic disease frequently arises. This review aims to describe the prognostic factors of chronic respiratory diseases in stable and in acute situations in order to improve the management of these complex situations. The various laws on patients' rights provide a legal framework and define the concept of unreasonable obstinacy. For patients with chronic obstructive pulmonary disease, the most robust decision factors are good knowledge of the respiratory disease, the comorbidities, the history of previous exacerbations and patient preferences. In the case of idiopathic pulmonary fibrosis, it is necessary to know if there is a prospect of transplantation and to assess the reversibility of the respiratory distress. In the case of amyotrophic lateral sclerosis, treatment decisions depend on the presence of advance directives about the use of intubation and tracheostomy. For lung cancer patients, general condition, cancer history and the tumor treatment plan are important factors. A multidisciplinary discussion that takes into account the patient's medical history, wishes and the current state of knowledge permits the taking of a coherent decision.

Chronic obstructive pulmonary disease prognostic score: A new index

BACKGROUND

The evaluation of chronic obstructive pulmonary disease (COPD) has been shifting from spirometry to focus on the patients' overall health. Despite the existence of many COPD prognostic scales, there remains a large gap for improvement, in particular a scale that incorporates the current focus on overall health.

METHODS

We proposed a new prognostic scale (the COPD Prognostic Score) through discussion among the authors based on published studies. Validation was retrospective, using data from the National Emphysema Treatment Trial.

RESULTS

The scores ranged from 0-16, where 16 indicated the poorest prognosis. We assigned 4 points each for forced expiratory volume in one second (%predicted), the modified Medical Research Council dyspnea scale, and age; 2 points for the hemoglobin level; and one point each for decreased activity and respiratory emergency admission in the last two years. The validation cohort included 607 patients and consisted of 388 men (73.9%) and 219 women (36.1%), mean age 67 ± 6 years and an average forced expiratory volume in one second (% predicted) of 27 ± 7%. A one-point increase in the score was associated with increased all-cause death, with a hazard ratio of 1.28 (95%CI: 1.21-1.36. P < 0.001). The areas under the receiver operating characteristic curves for two-year and five-year all-cause death for the new scale were 0.72 and 0.66, respectively. These values were higher than those given by the body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index and age, dyspnea, airway obstruction (ADO) index.

CONCLUSION

The preliminary validation for a new COPD prognostic scale: the COPD Prognostic Score was developed with promising results thus far. Above mentioned 16-point score accurately predicted 2-year and 5-year all-cause mortality among subjects who suffered from severe and very severe COPD.

The BODECOST Index (BCI): a composite index for assessing the impact of COPD in real life

Background

Chronic Obstructive Pulmonary Disease (COPD) is a progressive condition which is characterized by a dramatic socio-economic impact.

Several indices were extensively investigated in order to asses the mortality risk in COPD, but the utilization of health care resources was never included in calculations. The aim of this study was to assess the predictive value of annual cost of care on COPD mortality at three years, and to develop a comprehensive index for easy calculation of mortality risk in real life.

Methods

COPD patients were anonymously and automatically selected from the local institutional Data Base. Selection criteria were: COPD diagnosis; both genders; age ≥ 40 years; availability of at least one complete clinical record/year, including history; clinical signs; complete lung function, therapeutic strategy, health BODE index; Charlson Comorbidity Index, and outcomes, collected at the first visit, and over the following 3-years. At the first visit, the health annual cost of care was calculated in each patient for the previous 12 months, and the survival rate was also measured over the following 3 years. The hospitalization and the exacerbation rate were implemented to the BODE index and the novel index thus obtained was called BODECOST index (BCI), ranging from 0 to 10 points. The mean cost for each BCI step was calculated and then compared to the corresponding patients’ survival duration.

Parametrical, non parametrical tests, and linear regression were used; p < 0.05 was accepted as the lower limit of significance.

Results

At the first visit, the selected 275 patients were well matched for all variables by gender. The overall mortality over the 3 year survey was 40.4 % (n = 111/275). When compared to that of BODE index (r = 0.22), the total annual cost of care and the number of exacerbations showed the highest regression value vs the survival time (r = 0.58 and r = 0.44, respectively). BCI score proved strictly proportional to both the cost of care and the survival time in our sample of COPD patients.

Discussion

BCI takes origin from the implementation of the BODE index with the two main components of the annual cost of care, such as the number of hospitalizations and of exacerbations occurring yearly in COPD patients, and their corresponding economic impact. In other words, higher the BCI score, shorter the survival and higher the cost, these trends being strictly linked.

Conclusions

BCI is a novel composite index which helps in predicting the impact of COPD at 3 years in real life, both in terms of patients’ survival and of COPD economic burden.

A Multidimensional Risk Score to Predict All-Cause Hospitalization in Community-Dwelling Older Individuals With Obstructive Lung Disease

BACKGROUND

Both respiratory and nonrespiratory hospitalizations are common and costly events in older individuals with obstructive lung disease. Prevention of any hospitalization in these individuals is essential. We aimed to construct a prediction model for all-cause hospitalization risk in community-dwelling older individuals with obstructive lung disease.

METHODS

We studied 268 community-dwelling individuals with obstructive lung disease (defined as FEV1/FVC<LLN) who participated in the observational Health, Aging, and Body Composition Study and constructed a prediction model for 9-year all-cause hospitalization risk using a weighted linear combination based on beta coefficients.

RESULTS

There were 225 individuals with 1 or more hospitalizations and 43 individuals free from hospitalization during the follow-up. Heart and vascular disease (H), objectively measured lower extremity dysfunction (O), systemic inflammation (S), dyspnea (P), impaired renal function (I), and tobacco exposure (T) were independent predictors for all-cause hospitalization (ALL). These factors were combined into the HOSPITALL score (0-23 points), with an area under the curve in ROC analysis of 0.70 (P < .001). The hazard ratio for all-cause hospitalization per 1-point increase in the HOSPITALL score was 1.15 (95% confidence interval, 1.11-1.19, P = .001). Increasing HOSPITALL score was further associated with shorter time to first admission, increased admission rate, and more respiratory admissions.

CONCLUSION

The HOSPITALL score is a multidimensional score to predict all-cause hospitalization risk in community-dwelling older individuals with obstructive lung disease that may aid in patient counseling and prevention to reduce burden and health care costs.

Utilization due to chronic obstructive pulmonary disease and its predictors: a study using the U.S. National Emergency Department Sample (NEDS)

Background

Previous studies of healthcare utilization for chronic obstructive pulmonary disease (COPD) have focused on time-trends in COPD visits or COPD treatments, or the effect of hospital volume on mortality. Few data are available regarding outcomes after an ED visit (and subsequent hospitalization) for COPD, which are both very common in patients with COPD. Our objective was to assess time-trends and predictors of emergency department and subsequent inpatient health care utilization and charges associated with COPD in the U.S.

Method

We used the 2009-12 U.S. Nationwide Emergency Department Sample (NEDS) to study the incidence of ED visits and subsequent hospitalizations with COPD as the primary diagnosis. We used the 2012 NEDS data to study key patient/hospital factors associated with outcomes, including charges, hospitalization and dischage from hospital to home.

Results

ED visits for COPD as the primary diagnosis increased from 1.02 million in 2009 to 1.04 in 2010 to 1.10 million in 2012 (0.79–0.82 % of all ED visits); respective charges were $2.13, $2.32, and $3.09 billion. In 2012, mean ED charges/visit were $2,812, hospitalization charges/visit were $29,043 and the length of hospital stay was 4.3 days. 49 % were hospitalized after an ED visit. Older age, higher median income, metropolitan residence and comorbidities (diabetes, hypertension, HF, hyperlipidemia, CHD, renal failure and osteoarthritis) were associated with higher risk whereas male sex, Medicaid or self pay insurance status, hospital location in Midwest, South or West U.S. were associated with lower risk of hospitalization. 65.4 % of all patients hospitalized for COPD from ED were discharged home. Older age, comorbidities (diabetes, HF, CHD, renal failure, osteoarthritis) and metropolitan residence were associated with lower odds of discharge to home, whereas male sex, payer other than Medicare, Midwest, South or West U.S. hospital location were associated with higher odds.

Conclusion

Health care utilization and costs in patients with COPD are significant and increasing. COPD constitutes a major public health burden in the U.S. We identified risk factors for hospitalization, costs, and home discharge in patients with COPD that will allow future studies to investigate interventions to potentially reduce COPD-associated utilization.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0319-y) contains supplementary material, which is available to authorized users.

Understanding variation in length of hospital stay for COPD exacerbation: European COPD audit

Chronic obstructive pulmonary disease (COPD) care across Europe has high heterogeneity with respect to cost and the services available. Variations in length of stay (LOS) may be attributed to patient characteristics, resource and organisational characteristics, and/or the so-called hospital cluster effect. The European COPD Audit in 13 countries included data from 16 018 hospitalised patients. The recorded variables included information on patient and disease characteristics, and resources available. Variables associated with LOS were evaluated by a multivariate, multilevel analysis. Mean±sd LOS was 8.7±8.3 days (median 7 days, interquartile range 4-11 days). Crude variability between countries was reduced after accounting for clinical factors and the clustering effect. The main factors associated with LOS being longer than the median were related to disease or exacerbation severity, including GOLD class IV (OR 1.77) and use of mechanical ventilation (OR 2.15). Few individual resource variables were associated with LOS after accounting for the hospital cluster effect. This study emphasises the importance of the patients' clinical severity at presentation in predicting LOS. Identifying patients at risk of a long hospital stay at admission and providing targeted interventions offers the potential to reduce LOS for these individuals. The complex interactions between factors and systems were more important that any single resource or organisational factor in determining differences in LOS between hospitals or countries.

Predictors of Change in Dyspnea Level in Acute Exacerbations of COPD

The aim of this study was to identify factors related to changes in dyspnoea level in the acute and short-term periods after acute exacerbation of chronic obstructive pulmonary disease. This was a prospective cohort study of patients with symptoms of acute chronic obstructive pulmonary disease exacerbation who attended one of 17 hospitals in Spain between June 2008 and September 2010. Clinical data and patient reported measures (dyspnoea level, health-related quality of life, anxiety and depression levels, capacity to perform physical activity) were collected from arrival to the emergency department up to a week after the visit in discharged patients and to discharge in admitted patients (short term). Main outcomes were time course of dyspnoea over the acute (first 24 hours) and short-term periods, mortality and readmission within 2 months of the index episode. Changes in dyspnoea in both periods were related capacity to perform physical activity as well as clinical variables. Short-term changes in dyspnoea were also related to dyspnoea at 24 hours after the ED visit, and anxiety and depression levels. Dyspnoea worsening or failing to improve over the studied periods was associated with poor clinical outcomes. Patient-reported measures are predictive of changes in dyspnoea level.

Risk of exacerbation in chronic obstructive pulmonary disease: a primary care retrospective cohort study

Background

The risk of exacerbation in chronic obstructive pulmonary disease (COPD) depends on the severity of disease and other less well known factors. Predictive models of exacerbation are more accurate than the forced expiratory volume in one second (FEV1). The objective was to design a model that predicts the risk of exacerbation in COPD.

Methods

Retrospective cohort study with data from the electronic medical records of patients diagnosed with COPD in the province of Lleida (Spain). A total of 2501 patients were followed during 3 years. The dependent variable was acute exacerbation; independent variables were: clinical parameters, spirometry results, severity of disease, influenza and 23-valent pneumococcal immunisation, comorbidities, smoking and history of exacerbation. The association of these variables with disease exacerbation was measured by the adjusted odds ratio using a logistic regression model.

Results

Mean age at the start of the study was 68.38 years (SD = 11.60) and 74.97 % patients were men; severity of disease was considered mild in 50.82 % of patients, moderate in 35.31 %, severe in 9.44 % and very severe in 4.44 %. During the three year study period up to 83.17 % of patients experienced at least one exacerbation. Predictive factors in the model were age, gender, previous exacerbations, influenza and 23-valent pneumococcal immunisations, number of previous visits to the General Practice and severity (GOLD), with an area under the ROC curve (AUROC) of 0.70.

Conclusions

This model can identify patients at high risk of acute exacerbation. Preventive measures and modification of treatment in these high-risk patients would improve survival.

Hyperuricemia is a biomarker of early mortality in patients with chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease (COPD) are often at high risk of early death. Identification of prognostic biomarkers for COPD may aid in improving their survival by providing early strengthened therapy for high-risk patients. In the present study, we investigated the prognostic role of hyperuricemia at baseline on the prognosis of patients with COPD. Thirty-four patients with COPD with hyperuricemia were matched (1:2) to 68 patients with COPD without hyperuricemia and of similar age and sex. Data from those patients with COPD were evaluated retrospectively. The role of hyperuricemia on mortality was first analyzed using the Kaplan-Meier method, and multivariate Cox regression model was then used to evaluate the prognostic significance of hyperuricemia in patients with COPD. Hyperuricemia was not associated with other baseline characteristics in patients with COPD. Kaplan-Meier survival curve showed that patients with COPD with hyperuricemia had higher risk of mortality compared with patients with normouricemia, and the P-value for log-rank test was 0.005. In univariate analysis, hyperuricemia was associated with higher risk of mortality in patients with COPD (hazard ratio =2.29, 95% CI =1.07-4.88, P=0.032). In the multivariate analysis, hyperuricemia was independently associated with higher risk of mortality in patients with COPD (hazard ratio =2.68, 95% CI =1.18-6.09, P=0.019). In conclusion, hyperuricemia is a promising biomarker of early mortality in patients with COPD.