Determinants of blood eosinophil levels in the general population and patients with COPD: a population-based, epidemiological study.

BACKGROUND: Blood eosinophils are considered a biomarker for the treatment of chronic obstructive pulmonary disease (COPD). Population-based studies are needed to better understand the determinants of the blood eosinophil count (BEC) in individuals with and without COPD. METHODS: EPISCAN II is a multicentre, cross-sectional, population-based epidemiological study aimed at investigating the prevalence and determinants of COPD in Spain. Study subjects were randomly selected from the general population, and COPD was defined by a post-bronchodilator FEV1/FVC < 0.7. For the pre-specified outcomes related to BEC, the first 35 COPD and 35 non-COPD subjects were consecutively recruited in 12 of the participating centres with the objective of analysing 400 individuals in each group. Baseline BEC and its association with demographic, clinical and functional variables were analysed. RESULTS: A total of 326 COPD and 399 non-COPD subjects were included in the analysis. The mean age (standard deviation [SD]) was 63.2 years (11.0), 46.3% were male, and 27.6% were active smokers. BEC was significantly higher in individuals with COPD [192 cells/µL (SD: 125) vs. 160 cells/µL (SD: 114); p = 0.0003]. In a stepwise multivariate model, being male, active smoker and having a previous diagnosis of asthma were independently associated with having a higher BEC. CONCLUSIONS: This population-based study estimated the distribution of eosinophils in the healthy adult population and concluded that COPD patients have a significantly higher BEC. Male sex, active smoking and concomitant asthma were significantly associated with a higher BEC.

External Validation and Recalculation of the CODEX Index in COPD Patients. A 3CIAplus Cohort Study.

The CODEX index was developed and validated in patients hospitalized for COPD exacerbation to predict the risk of death and readmission within one year after discharge. Our study aimed to validate the CODEX index in a large external population of COPD patients with variable durations of follow-up. Additionally, we aimed to recalculate the thresholds of the CODEX index using the cutoffs of variables previously suggested in the 3CIA study (mCODEX). Individual data on 2,755 patients included in the COPD Cohorts Collaborative International Assessment Plus (3CIA+) were explored. A further two cohorts (ESMI AND EGARPOC-2) were added. To validate the CODEX index, the relationship between mortality and the CODEX index was assessed using cumulative/dynamic ROC curves at different follow-up periods, ranging from 3 months up to 10 years. Calibration was performed using univariate and multivariate Cox proportional hazard models and Hosmer-Lemeshow test. A total of 3,321 (87.8% males) patients were included with a mean ± SD age of 66.9 ± 10.5 years, and a median follow-up of 1,064 days (IQR 25-75% 426-1643), totaling 11,190 person-years. The CODEX index was statistically associated with mortality in the short- (≤3 months), medium- (≤1 year) and long-term (10 years), with an area under the curve of 0.72, 0.70 and 0.76, respectively. The mCODEX index performed better in the medium-term (<1 year) than the original CODEX, and similarly in the long-term. In conclusion, CODEX and mCODEX index are good predictors of mortality in patients with COPD, regardless of disease severity or duration of follow-up.

Large-scale external validation and comparison of prognostic models: an application to chronic obstructive pulmonary disease.

BACKGROUND: External validations and comparisons of prognostic models or scores are a prerequisite for their use in routine clinical care but are lacking in most medical fields including chronic obstructive pulmonary disease (COPD). Our aim was to externally validate and concurrently compare prognostic scores for 3-year all-cause mortality in mostly multimorbid patients with COPD. METHODS: We relied on 24 cohort studies of the COPD Cohorts Collaborative International Assessment consortium, corresponding to primary, secondary, and tertiary care in Europe, the Americas, and Japan. These studies include globally 15,762 patients with COPD (1871 deaths and 42,203 person years of follow-up). We used network meta-analysis adapted to multiple score comparison (MSC), following a frequentist two-stage approach; thus, we were able to compare all scores in a single analytical framework accounting for correlations among scores within cohorts. We assessed transitivity, heterogeneity, and inconsistency and provided a performance ranking of the prognostic scores. RESULTS: Depending on data availability, between two and nine prognostic scores could be calculated for each cohort. The BODE score (body mass index, airflow obstruction, dyspnea, and exercise capacity) had a median area under the curve (AUC) of 0.679 [1st quartile-3rd quartile = 0.655-0.733] across cohorts. The ADO score (age, dyspnea, and airflow obstruction) showed the best performance for predicting mortality (difference AUCADO - AUCBODE = 0.015 [95% confidence interval (CI) = -0.002 to 0.032]; p = 0.08) followed by the updated BODE (AUCBODE updated - AUCBODE = 0.008 [95% CI = -0.005 to +0.022]; p = 0.23). The assumption of transitivity was not violated. Heterogeneity across direct comparisons was small, and we did not identify any local or global inconsistency. CONCLUSIONS: Our analyses showed best discriminatory performance for the ADO and updated BODE scores in patients with COPD. A limitation to be addressed in future studies is the extension of MSC network meta-analysis to measures of calibration. MSC network meta-analysis can be applied to prognostic scores in any medical field to identify the best scores, possibly paving the way for stratified medicine, public health, and research.

Achieving Thoracic Oncology data collection in Europe: a precursor study in 35 Countries.

BACKGROUND: A minority of European countries have participated in international comparisons with high level data on lung cancer. However, the nature and extent of data collection across the continent is simply unknown, and without accurate data collection it is not possible to compare practice and set benchmarks to which lung cancer services can aspire. METHODS: Using an established network of lung cancer specialists in 37 European countries, a survey was distributed in December 2014. The results relate to current practice in each country at the time, early 2015. The results were compiled and then verified with co-authors over the following months. RESULTS: Thirty-five completed surveys were received which describe a range of current practice for lung cancer data collection. Thirty countries have data collection at the national level, but this is not so in Albania, Bosnia-Herzegovina, Italy, Spain and Switzerland. Data collection varied from paper records with no survival analysis, to well-established electronic databases with links to census data and survival analyses. CONCLUSION: Using a network of committed clinicians, we have gathered validated comparative data reporting an observed difference in data collection mechanisms across Europe. We have identified the need to develop a well-designed dataset, whilst acknowledging what is feasible within each country, and aspiring to collect high quality data for clinical research.

Prevalence of persistent blood eosinophilia: relation to outcomes in patients with COPD.

The impact of blood eosinophilia in chronic obstructive pulmonary disease (COPD) remains controversial.To evaluate the prevalence and stability of a high level of blood eosinophils (≥300 cells·µL-1) and its relationship to outcomes, we determined blood eosinophils at baseline and over 2 years in 424 COPD patients (forced expiratory volume in 1 s (FEV1) 60% predicted) and 67 smokers without COPD from the CHAIN cohort, and in 308 COPD patients (FEV1 60% predicted) in the BODE cohort. We related eosinophil levels to exacerbations and survival using Cox hazard analysis.In COPD patients, 15.8% in the CHAIN cohort and 12.3% in the BODE cohort had persistently elevated blood eosinophils at all three visits. A significant proportion (43.8%) of patients had counts that oscillated above and below the cut-off points, while the rest had persistent eosinophil levels <300 cells·µL-1 A similar eosinophil blood pattern was observed in controls. Exacerbation rates did not differ in patients with and without eosinophilia. All-cause mortality was lower in patients with high eosinophils compared with those with values <300 cells·µL-1 (15.8% versus 33.7%; p=0.026).In patients with COPD, blood eosinophils ≥300 cells·µL-1 persisting over 2 years was not a risk factor for COPD exacerbations. High eosinophil count was associated with better survival.

A simple algorithm for the identification of clinical COPD phenotypes.

This study aimed to identify simple rules for allocating chronic obstructive pulmonary disease (COPD) patients to clinical phenotypes identified by cluster analyses.Data from 2409 COPD patients of French/Belgian COPD cohorts were analysed using cluster analysis resulting in the identification of subgroups, for which clinical relevance was determined by comparing 3-year all-cause mortality. Classification and regression trees (CARTs) were used to develop an algorithm for allocating patients to these subgroups. This algorithm was tested in 3651 patients from the COPD Cohorts Collaborative International Assessment (3CIA) initiative.Cluster analysis identified five subgroups of COPD patients with different clinical characteristics (especially regarding severity of respiratory disease and the presence of cardiovascular comorbidities and diabetes). The CART-based algorithm indicated that the variables relevant for patient grouping differed markedly between patients with isolated respiratory disease (FEV1, dyspnoea grade) and those with multi-morbidity (dyspnoea grade, age, FEV1 and body mass index). Application of this algorithm to the 3CIA cohorts confirmed that it identified subgroups of patients with different clinical characteristics, mortality rates (median, from 4% to 27%) and age at death (median, from 68 to 76 years).A simple algorithm, integrating respiratory characteristics and comorbidities, allowed the identification of clinically relevant COPD phenotypes.

Prognostic assessment in COPD without lung function: the B-AE-D indices.

Several composite markers have been proposed for risk assessment in chronic obstructive pulmonary disease (COPD). However, choice of parameters and score complexity restrict clinical applicability. Our aim was to provide and validate a simplified COPD risk index independent of lung function.The PROMISE study (n=530) was used to develop a novel prognostic index. Index performance was assessed regarding 2-year COPD-related mortality and all-cause mortality. External validity was tested in stable and exacerbated COPD patients in the ProCOLD, COCOMICS and COMIC cohorts (total n=2988).Using a mixed clinical and statistical approach, body mass index (B), severe acute exacerbations of COPD frequency (AE), modified Medical Research Council dyspnoea severity (D) and copeptin (C) were identified as the most suitable simplified marker combination. 0, 1 or 2 points were assigned to each parameter and totalled to B-AE-D or B-AE-D-C. It was observed that B-AE-D and B-AE-D-C were at least as good as BODE (body mass index, airflow obstruction, dyspnoea, exercise capacity), ADO (age, dyspnoea, airflow obstruction) and DOSE (dyspnoea, obstruction, smoking, exacerbation) indices for predicting 2-year all-cause mortality (c-statistic: 0.74, 0.77, 0.69, 0.72 and 0.63, respectively; Hosmer-Lemeshow test all p>0.05). Both indices were COPD specific (c-statistic for predicting COPD-related 2-year mortality: 0.87 and 0.89, respectively). External validation of B-AE-D was performed in COCOMICS and COMIC (c-statistic for 1-year all-cause mortality: 0.68 and 0.74; c-statistic for 2-year all-cause mortality: 0.65 and 0.67; Hosmer-Lemeshow test all p>0.05).The B-AE-D index, plus copeptin if available, allows a simple and accurate assessment of COPD-related risk.

Age-related risk factors for bacterial aetiology in community-acquired pneumonia.

BACKGROUND AND OBJECTIVE: The objective of this study was to evaluate the effect of age and comorbidities, smoking and alcohol use on microorganisms in patients with community-acquired pneumonia (CAP). METHODS: A prospective multicentre study was performed with 4304 patients. We compared microbiological results, bacterial aetiology, smoking, alcohol abuse and comorbidities in three age groups: young adults (<45 years), adults (45-64 years) and seniors (>65 years). RESULTS: Bacterial aetiology was identified in 1522 (35.4%) patients. In seniors, liver disease was independently associated with Gram-negative bacteria (Haemophilus influenzae and Enterobacteriaceae), COPD with Pseudomonas aeruginosa (OR = 2.69 (1.46-4.97)) and Staphylococcus aureus (OR = 2.8 (1.24-6.3)) and neurological diseases with S. aureus. In adults, diabetes mellitus (DM) was a risk factor for Streptococcus pneumoniae and S. aureus, and COPD for H. influenzae (OR = 3.39 (1.06-10.83)). In young adults, DM was associated with S. aureus. Smoking was a risk factor for Legionella pneumophila regardless of age. Alcohol intake was associated with mixed aetiology and Coxiella burnetii in seniors, and with S. pneumoniae in young adults. CONCLUSION: It should be considered that the bacterial aetiology may differ according to the patient's age, comorbidities, smoking and alcohol abuse. More extensive microbiological testing is warranted in those with risk factors for infrequent microorganisms.

New GOLD classification: longitudinal data on group assignment.

RATIONALE: Little is known about the longitudinal changes associated with using the 2013 update of the multidimensional GOLD strategy for chronic obstructive pulmonary disease (COPD). OBJECTIVE: To determine the COPD patient distribution of the new GOLD proposal and evaluate how this classification changes over one year compared with the previous GOLD staging based on spirometry only. METHODS: We analyzed data from the CHAIN study, a multicenter observational Spanish cohort of COPD patients who are monitored annually. Categories were defined according to the proposed GOLD: FEV1%, mMRC dyspnea, COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ), and exacerbations-hospitalizations. One-year follow-up information was available for all variables except CCQ data. RESULTS: At baseline, 828 stable COPD patients were evaluated. On the basis of mMRC dyspnea versus CAT, the patients were distributed as follows: 38.2% vs. 27.2% in group A, 17.6% vs. 28.3% in group B, 15.8% vs. 12.9% in group C, and 28.4% vs. 31.6% in group D. Information was available for 526 patients at one year: 64.2% of patients remained in the same group but groups C and D show different degrees of variability. The annual progression by group was mainly associated with one-year changes in CAT scores (RR, 1.138; 95%CI: 1.074-1.206) and BODE index values (RR, 2.012; 95%CI: 1.487-2.722). CONCLUSIONS: In the new GOLD grading classification, the type of tool used to determine the level of symptoms can substantially alter the group assignment. A change in category after one year was associated with longitudinal changes in the CAT and BODE index.

Association between occupational exposure and chronic obstructive pulmonary disease and respiratory symptoms in the Spanish population.

INTRODUCTION: The aim of this study was to analyze the impact of occupational exposure on chronic obstructive pulmonary disease (COPD) and respiratory symptoms in the general Spanish population. METHODS: This was a study nested in the Spanish EPISCAN II cross-sectional epidemiological study that included participants who had completed a structured questionnaire on their occupational history, a questionnaire on respiratory symptoms, and forced spirometry. The data were analyzed using Chi-square and Student's t tests and adjusted models of multiple linear regression and logistic regression. RESULTS: We studied 7502 subjects, 51.1% women, with a mean age of 60±11 years. Overall, 53.2% reported some respiratory symptoms, 7.9% had respiratory symptoms during their work activity, 54.2% were or had been smokers, and 11.3% (851 subjects) met COPD criteria on spirometry. A total of 3056 subjects (40.7%) reported exposure to vapors, gases, dust or fumes (VGDF); occupational exposure to VGDF was independently associated with the presence of COPD (OR 1.22, 95% CI: 1.03-1.44), respiratory symptoms (OR 1.45, 95%: CI 1.30-1.61), and respiratory symptoms at work (OR 4.69, 95% CI: 3.82-5.77), with a population attributable fraction for COPD of 8.2%. CONCLUSIONS: Occupational exposure is associated with a higher risk of COPD and respiratory symptoms in the Spanish population. These results highlight the need to follow strict prevention measures to protect the respiratory health of workers.

Microbial aetiology of healthcare associated pneumonia in Spain: a prospective, multicentre, case-control study.

INTRODUCTION: Healthcare-associated pneumonia (HCAP) is actually considered a subgroup of hospital-acquired pneumonia due to the reported high risk of multidrug-resistant pathogens in the USA. Therefore, current American Thoracic Society/Infectious Diseases Society of America guidelines suggest a nosocomial antibiotic treatment for HCAP. Unfortunately, the scientific evidence supporting this is contradictory. METHODS: We conducted a prospective multicentre case-control study in Spain, comparing clinical presentation, outcomes and microbial aetiology of HCAP and community-acquired pneumonia (CAP) patients matched by age (±10 years), gender and period of admission (±10 weeks). RESULTS: 476 patients (238 cases, 238 controls) were recruited for 2 years from June 2008. HCAP cases showed significantly more comorbidities (including dysphagia), higher frequency of previous antibiotic use in the preceding month, higher pneumonia severity score and worse clinical status (Charslon and Barthel scores). While microbial aetiology did not differ between the two groups (HCAP and CAP: Streptococcus pneumoniae: 51% vs 55%; viruses: 22% vs 12%; Legionella: 4% vs 9%; Gram-negative bacilli: 5% vs 4%; Pseudomonas aeruginosa: 4% vs 1%), HCAP patients showed worse mortality rates (1-month: HCAP, 12%; CAP 5%; 1-year: HCAP, 24%; CAP, 9%), length of hospital stay (9 vs 7 days), 1-month treatment failure (5.5% vs 1.5%) and readmission rate (18% vs 11%) (p<0.05, each). CONCLUSIONS: Despite a similar clinical presentation, HCAP was more severe due to patients' conditions (comorbidities) and showed worse clinical outcomes. Microbial aetiology of HCAP did not differ from CAP indicating that it is not related to increased mortality and in Spain most HCAP patients do not need nosocomial antibiotic coverage.

Multicomponent indices to predict survival in COPD: the COCOMICS study.

Guidelines recommend defining chronic obstructive pulmonary disease (COPD) by airflow obstruction and other factors, but no studies have evaluated the ability of existing multicomponent indices to predict mortality up to 10 years. We conducted a patient-based pooled analysis. Survival analysis and C statistics were used to determine the best COPD index/indices according to several construct variables and by varying time-points. Individual data of 3633 patients from 11 COPD cohorts were collected, totalling the experience of 15 878 person-years. Overall, there were 1245 death events within our cohorts, with a Kaplan-Meier survival of 0.963 at 6 months, which was reduced to 0.432 at 10 years. In all patients, ADO (age, dyspnoea and forced expiratory volume in 1 s), BODE (body mass index, airflow obstruction, dyspnoea and exercise capacity) and e-BODE (BODE plus exacerbations) were the best indices to predict 6-month mortality. The ADO index was the best to predict 12-month (C statistic 0.702), 5-year (C statistic 0.695) and 10-year mortality (C statistic 0.698), and was significantly better than BODE (all p<0.05). The best indices to predict death by C statistics when adjusting by age were e-BODE, BODEx (substitution of exacerbations for exercise capacity) and BODE. No index predicts short-term survival of COPD well. All BODE modifications scored better than ADO after age adjustment. The ADO and BODE indices are overall the most valid multicomponent indices to predict time to death in all COPD patients.

Prevalence of reduced lung diffusing capacity and CT scan findings in smokers without airflow limitation: a population-based study.

BACKGROUND: Population distribution of reduced diffusing capacity of the lungs for carbon monoxide (DLCO) in smokers and main consequences are not properly recognised. The objectives of this study were to describe the prevalence of reduced DLCO in a population-based sample of current and former smoker subjects without airflow limitation and to describe its morphological, functional and clinical implications. METHODS: A sample of 405 subjects aged 40 years or older with postbronchodilator forced expiratory volume in 1 s/forced vital capacity (FVC) >0.70 was obtained from a random population-based sample of 9092 subjects evaluated in the EPISCAN II study. Baseline evaluation included clinical questionnaires, exhaled carbon monoxide (CO) measurement, spirometry, DLCO determination, 6 min walk test, routine blood analysis and low-dose CT scan with evaluation of lung density and airway wall thickness. RESULTS: In never, former and current smokers, prevalence of reduced DLCO was 6.7%, 14.4% and 26.7%, respectively. Current and former smokers with reduced DLCO without airflow limitation were younger than the subjects with normal DLCO, and they had greater levels of dyspnoea and exhaled CO, greater pulmonary artery diameter and lower spirometric parameters, 6 min walk distance, daily physical activity and plasma albumin levels (all p<0.05), with no significant differences in other chronic respiratory symptoms or CT findings. FVC and exhaled CO were identified as independent risk factors for low DLCO. CONCLUSION: Reduced DLCO is a frequent disorder among smokers without airflow limitation, associated with decreased exercise capacity and with CT findings suggesting that it may be a marker of smoking-induced early vascular damage. TRIAL REGISTRATION NUMBER: NCT03028207.

Unravelling young COPD and pre-COPD in the general population.

Background: Chronic obstructive pulmonary disease (COPD) is commonly diagnosed when the airflow limitation is well established and symptomatic. We aimed to identify individuals at risk of developing COPD according to the concept of pre-COPD and compare their clinical characteristics with 1) those who have developed the disease at a young age, and 2) the overall population with and without COPD. Methods: The EPISCAN II study is a cross-sectional, population-based study that aims to investigate the prevalence of COPD in Spain in subjects ≥40 years of age. Pre-COPD was defined as the presence of emphysema >5% and/or bronchial thickening by computed chromatography (CT) scan and/or diffusing capacity of the lung for carbon monoxide (D LCO) <80% of predicted in subjects with respiratory symptoms and post-bronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) >0.70. Young COPD was defined as FEV1/FVC <0.70 in a subject ≤50 years of age. Demographic and clinical characteristics were compared among pre-COPD, young COPD and the overall population with and without COPD. Results: Among the 1077 individuals with FEV1/FVC <0.70, 65 (6.0%) were ≤50 years of age. Among the 8015 individuals with FEV1/FVC >0.70, 350 underwent both D LCO testing and chest CT scanning. Of those, 78 (22.3%) subjects fulfilled the definition of pre-COPD. Subjects with pre-COPD were older, predominantly women, less frequently active or ex-smokers, with less frequent previous diagnosis of asthma but with higher symptomatic burden than those with young COPD. Conclusions: 22.3% of the studied population was at risk of developing COPD, with similar symptomatic and structural changes to those with well-established disease without airflow obstruction. This COPD at-risk population is different from those that develop COPD at a young age.

Dissociation between physical capacity and daily physical activity in COPD patients. A population-based approach.

BADKGROUND: Physical capacity (PC) and daily physical activity (PA) are two crucial factors in the clinical course of COPD, although they do not always maintain a close relationship. The objectives were to evaluate the frequency of PC-PA dissociation in patients with COPD and subjects without airflow limitation (AL) and to identify its risk factors. METHODS: A sample of 319 COPD patients and 399 subjects without AL was consecutively obtained from a population-based sample of 9092 subjects evaluated in the EPISCAN II study. Baseline evaluation included clinical questionnaires, lung function testing, blood analysis and low-dose computed tomography (CT) scan with evaluation of lung density and airway wall thickness. A distance walked in 6 min > 70% predicted was considered an indicator of normal PC, while a Yale Physical Activity Survey summary index score <51 was used to identify with sedentary lifestyle. RESULTS: 166 COPD patients (52.0%) reported a sedentary lifestyle with evidence of preserved PC, while this phenomenon was present in 188 (47.1%) subjects without AL. In the COPD group, symptoms of chronic bronchitis, depression and elevated hematocrit and blood eosinophil count were identified as independent risk factors for PC-PA dissociation. In turn, in the subjects without AL, the risk factors for PC-PA dissociation were low fat-free mass, obesity and anxiety, as well as reduced levels of HDL-cholesterol and the absence of osteoporosis. CONCLUSIONS: Almost half of COPD patients and subjects without airflow limitation with preserved PC maintain a sedentary lifestyle, with different risk factors for sedentarism between both groups.

Trends of COPD in Spain: Changes Between Cross Sectional Surveys 1997, 2007 and 2017.

INTRODUCTION: We aim to describe the changes in prevalence and risk factors associated to chronic obstructive pulmonary disease (COPD) in Spain, comparing three population-based studies conducted in three timepoints. METHODS: We compared participants from IBERPOC conducted in 1997, EPISCAN conducted in 2007 and EPISCAN II in 2017. COPD was defined as a postbronchodilator FEV1/FVC (forced expiratory volume in 1s/forced vital capacity) ratio <0.70, according to GOLD criteria; subsequently, also as the FEV1/FVC below the lower limit of normal (LLN). RESULTS: COPD prevalence in the population between 40 and 69 years decreased from 21.6% (95% CI 20.7%-23.2%) in 1997 to 8.8% (95% CI 8.2%-9.5%) in 2017, a 59.2% decline (p<0.001). In 2007, the prevalence was 7.7% (95% CI 6.8%-8.7%) with an upward trend of 1.1 percentage points in 2017 (p=0.073). Overall COPD prevalence decreased in men and women, although a significant increase was observed in the last decade in females (p<0.05). Current smokers significantly increased in the last decades (25.4% in 1997, 29.1% in 2007 and 23.4% in 2017; p<0.001). Regrettably, COPD underdiagnosis was constantly high, 77.6% in 1997, 78.4% in 2007, and to 78.2% in 2017 (p=0.95), higher in younger ages (40-49 yrs and 50-59 yrs) and also higher in women than in men in all three studies (p<0.05). CONCLUSIONS: We report a significant reduction of 59.2% in the prevalence of COPD in Spain from 1997 to 2017 in subjects aged 40-69 years. Our study highlights the significant underdiagnosis of COPD, particularly sustained in women and younger populations.

Tobacco Patterns and Risk of Chronic Obstructive Pulmonary Disease: Results From a Cross-Sectional Study.

INTRODUCTION: There is still uncertainty about which aspects of cigarette smoking influence the risk of Chronic Obstructive Pulmonary Disease (COPD). The aim of this study was to estimate the COPD risk as related to duration of use, intensity of use, lifetime tobacco consumption, age of smoking initiation and years of abstinence. METHODS: We conducted an analytical cross-sectional study based on data from the EPISCAN-II study (n=9092). All participants underwent a face-to-face interview and post-bronchodilator spirometry was performed. COPD was defined as post-bronchodilator FEV1/FVC<70%. Parametric and nonparametric logistic regression models with generalized additive models were used. RESULTS: 8819 persons were included; 858 with COPD and 7961 without COPD. The COPD risk increased with smoking duration up to ≥50 years [OR 3.5 (95% CI: 2.3-5.4)], with smoking intensity up to ≥39cig/day [OR 10.1 (95% CI: 5.3-18.4)] and with lifetime tobacco consumption up to >29 pack-years [OR 3.8 (95% CI: 3.1-4.8)]. The COPD risk for those who started smoking at 22 or later was 0.9 (95% CI: 0.6-1.4). The risk of COPD decreased with increasing years of cessation. In comparison with both never smokers and current smokers, the lowest risk of COPD was found after 15-25 years of abstinence. CONCLUSION: COPD risk increases with duration, intensity, and lifetime tobacco consumption and decreases importantly with years of abstinence. Age at smoking initiation shows no effect. After 15-25 years of cessation, COPD risk could be equal to that of a never smoker. This work suggests that the time it takes to develop COPD in a smoker is about 30 years.

Respiratory symptoms and their determinants in the general Spanish population: changes over 20 years.

Background: Few large epidemiological studies have analysed the prevalence of respiratory symptoms and their determinants in the general adult population. We investigated the prevalence and determinants of respiratory symptoms and compared their prevalence with that of two previous studies conducted in 1999 and 2009. Method: EPISCAN II was a multicentre, cross-sectional, population-based epidemiological study in individuals older than 40 years. Results: A total of 9092 individuals were included. Up to 47.5% reported at least one respiratory symptom, being more frequent in women than in men (49.4% versus 45.5%, p=0.0002) and with wheezing being the most frequent (33.7%) followed by dyspnoea (26.8%). The presence of any symptom was associated with female sex, higher body mass index (BMI), lower forced expiratory volume in 1 s (FEV1 % pred), reduced physical activity, a higher Charlson index and the presence of anxiety and depression. Smoking was also significantly associated with having at least one respiratory symptom in a dose-response fashion (OR: 1.415, 1.916, 2.192 and 2.987 for 0-10, 10-20, 20-30 and >30 pack-years, respectively, all p<0.0001). The prevalence of symptoms remained quite similar over the last 20 years (wheezing 40%, 36% and 33.7% and dyspnoea 10.4%, 9.9% and 13.1% in 1999, 2009 and 2019, respectively). Conclusions: Approximately half of the adult Spanish population have respiratory symptoms and this prevalence has remained quite stable over the last 20 years. Smoking remains the main factor associated with respiratory symptoms, but female sex, comorbidities, high BMI and low FEV1 and low physical activity are also significantly associated with respiratory symptoms.

Prevalence and Determinants of COPD in Spain: EPISCAN II.

BACKGROUND: Two previous national epidemiological studies, IBERPOC in 1997 and EPISCAN in 2007, determined the COPD burden in Spain. Changes in demographics and exposure to risk factors demand the periodic update of COPD prevalence and its determinants. METHODS: EPISCAN II aimed to estimate the prevalence of COPD in the general population aged 40 years or older in all 17 regions of Spain. A random population screening sample, requiring 600 participants per region performed a questionnaire plus post-bronchodilator (post-BD) spirometry. RESULTS: A total of 12,825 subjects were initially contacted, and 9433 (73.6%) agreed to participate, of whom 9092 performed a valid spirometry. Baseline characteristics were: 52.6% women, mean±SD age 60±11 years, 19.8% current- and 34.2% former-smokers. The prevalence of COPD measured by post-BD fixed ratio FEV1/FVC<0.7 was 11.8% (95% C.I. 11.2-12.5) with a high variability by region (2.4-fold). Prevalence was 14.6% (95% C.I. 13.5-15.7) in males and 9.4% (95% C.I. 8.6-10.2) in females; according to the lower limit of normal (LLN) was 6.0% (95% C.I. 5.5-6.5) overall, by sex being 7.1% (95% C.I. 6.4-8.0) in males and 4.9% (95% C.I. 4.3-5.6) in females. Underdiagnosis of COPD was 74.7%. Cases with COPD were a mean of seven years older, more frequently male, of lower attained education, and with more smokers than the non-COPD population (p<0.001). However, the number of cigarettes and pack-years in non-COPD participants was substantial, as it was the reported use of e-cigarettes (7.0% vs. 5.5%) (p=0.045). There were also significant social and clinical differences including living alone, previous respiratory diagnoses, more comorbidities measured with the Charlson index, greater BODE and COTE scores, cognitive impairment, and depression (all p<0.001). CONCLUSIONS: COPD remains prevalent in Spain and frequently underdiagnosed.

The effect of airflow limitation on the cause of death in patients with COPD.

COPD is characterized by airflow limitation that is usually progressive. The present study investigated the cause of death and the effect of airflow limitation on all-cause mortality in COPD patients. A prospective cohort of 600 COPD patients were followed for 3 years. Patients in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 2 (32.7%), GOLD 3 (48.1%), or GOLD 4 (19.1%). Overall, 117 patients died (19.6%). Deaths were due to respiratory failure (29%), cardiovascular disease (25.6%), cancer (17.9%), infection (11%), gastrointestinal disease (9.4%), and other causes (6.7%). According to the Cox regression analysis, the following independent factors were related to mortality: age (years), hazards ratio (HR) 1.046 (confidence interval [CI] 95% 1.021, 1.072); current smoking status, HR 1.535 (CI 95% 1.003, 2.350); cancer, HR 7.172 (CI 95% 4.515, 11.395); cardiovascular disease, HR 2.623 (CI 95% 1.821, 3.778); severe airflow limitation (GOLD 4), HR 2.378 (CI 95% 1.605, 3.525); and highest quartile of acute exacerbations, HR 1.852 (CI 95% 1.236, 2.775). The present study shows that severe airflow limitation, current smoking status, the presence of cardiovascular disease, cancer, and a high frequency of acute exacerbations have an independent negative impact on the prognosis of COPD patients.