Chronic obstructive respiratory diseases

Introduction

Chronic obstructive pulmonary disease (COPD) is a leading cause of chronic morbidity. The American Thoracic Society (ATS) has defined COPD as "a limitation due to chronic bronchitis or emphysema: the airflow obstruction is generally reversible". The European Respiratory Society (ERS) defined COPD as "reduced maximum expiratory flow and slow forced emptying of the lungs which is slow progressive and mostly irreversible to present medical treatment". More recently, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) defined COPD as "a disease state characterized by airflow limitation that is not fully reversible. The airflow limitation is usually both progressive and associated with and abnormal inflammatory response of the lungs to noxious particles or gases". However, the precise classification of the airflow, reversibility, and severity of disease varies. Differences in the definition may produce variations on the estimates more than 200%.

Responding to the need of comparable indicators for COPD monitoring

The objective of the Community action in the field of public health (2003-2008) is to evaluate the impact on COPD prevalence of possible health policy interventions. These interventions should also focus on the reduction of specific COPD risk factors. For this purpose the European Commission supports, on the framework of the Community action in the field of public health, the EU project IMCA (Indicators for Monitoring COPD and asthma in the EU) to develop indicators to monitor asthma and COPD in the European Union, to describe the prevalence of COPD related symptoms, asthma at tacks, physician diagnosed COPD by age group, gender, socioeconomic status and geographical area and to monitor changes over time on the indicators proposed. The general objective of the IMCA project was to get a consensus among the project participants on a set of indicators for monitoring the prevalence, risk factors, clinical management and outcomes of COPD in the EU. Taking this list as starting point and according to the methodology approved by the Steering Committee and the IMCA group, the coordinating centre has further developed the list creating the "Initial matrix of indicators for COPD". This matrix, organized the indicators selected according to the framework already established by the European Community Health Indicators (ECHI) project, which is the main framework, supported and required by DG Health and Consumer Protection.

See IMCA II - Indicators for Monitoring COPD and Asthma in the EU

The need of comparable prevalence COPD rate

The number of epidemiological studies which have assessed the prevalence of COPD is still limited. Information on the prevalence of COPD can be obtained from two main sources of data: 1) general health interview or examination surveys and 2) research studies. However, the quality of the information is very poor and limited in general health interview surveys and the information provided from research studies is difficult to compare. The data quality mainly depends on the methods used in each specific study. However, the most relevant problems seems to be the difficulties in comparing results between studies due to the lack of consensus on the methods and definitions.

Thirty-two sources of COPD prevalence rates, representing 17 countries and eight World Health Organization-classified regions, were identified and reviewed by Hallbert et al. Prevalence estimates were based on spirometry (11 studies), respiratory symptoms (14 studies), patient-reported disease (10 studies), or expert opinion. Reported prevalence ranged from 0.23 to 18.3%. The lowest prevalence rates (0.2 to 2.5%) were based on expert opinion. Sixteen studies had measured rates that could reasonably be extrapolated to an entire region or country. All were for Europe or North America, and most fell between 4% and 10%. There is considerable variation in the reported prevalence of COPD. The overall prevalence in adults appears to lie between 4% and 10% in countries where it has been rigorously measured. Some of the variation attributed to differences in risk exposure or population characteristics may be influenced by the methods and definitions used to measure disease. Spirometry is least influenced by local diagnostic practice, but it is subject to variation based on the lung function parameters selected to define COPD.

See Interpreting COPD Prevalence Estimates. What Is the True Burden of Disease? Hallbert et al.

The international study "The Confronting COPD International Survey" aimed to quantify morbidity and burden in COPD subjects in 2000. From a total of 201 921 households screened by random-digit dialling in the USA, Canada, France, Italy, Germany, The Netherlands, Spain and the UK, 3 265 subjects with a diagnosis of COPD, chronic bronchitis or emphysema, or with symptoms of chronic bronchitis, were identified. The mean age of the subjects was 63.3 yrs and 44.2% were female. Subjects with COPD in North America and Europe appear to underestimate their morbidity, as shown by the high proportion of subjects with limitations to their basic daily life activities, frequent work loss (45.3% of COPD subjects of <65 yrs reported work loss in the past year) and frequent use of health services (13.8% of subjects required emergency care in the last year), and may be undertreated. This international survey confirmed the great burden to society and high individual morbidity associated with chronic obstructive pulmonary disease in subjects in North America and Europe. The definition used in this study was: "Proportion of individuals aged ³45 years who had cumulative cigarette consumption of ³10 pack-years and who had been diagnosed with COPD, emphysema or chronic bronchitis, or whose symptoms fulfilled a definition of chronic bronchitis, i.e. "persistent coughing with phleghm or sputum from the chest for the last 2 years or more".

See The burden of COPD in France: results from the Confronting COPD survey
See The burden of COPD in Italy: results from the Confronting COPD survey
See The burden of COPD in The Netherlands: results from the Confronting COPD survey
See The burden of COPD in Spain: results from the Confronting COPD survey
See The burden of COPD in the U.K.: results from the Confronting COPD survey
See Economic analysis of the Confronting COPD survey: an overview of results

In 1995, the European Respiratory Society published a European Consensus Statement on the optimal assessment and management of COPD. In the document, several important areas for future research are identified that may help to increase knowledge of the current situation of COPD within Europe; these include pathophysiology, epidemiology, and the clinical benefits of treatment. This article reviews a selection of important data that have become available since the consensus statement was published, with a specific focus on epidemiology and treatment.

See COPD: The Scope of the Problem in Europe - European Respiratory Society

The need of respiratory system mortality comparable data

A wide range of pathologies comes under the heading of 'diseases of the respiratory system'. In addition to cancerous diseases, a distinction is made between infectious and acute respiratory diseases (influenza, pneumonia) and chronic obstructive diseases. The borderline between the two is not, however, clear-cut, and when respiratory infections are recurrent or are accompanied by complications, they can cause chronic complaints. These respiratory diseases together with respiratory cancers are a major cause of mortality in a number of Member States. For the European Union as a whole, they account for 17 % of male deaths and 10 % of female deaths. Variations in regional mortality rates are very pronounced in the EU both for chronic diseases and infectious diseases.

Chronic respiratory diseases (chronic pulmonary diseases, emphysema and asthma) account for 4.4 % of male deaths and 2.6 % of female deaths in the EU. Of these, chronic obstructive pulmonary diseases (COPD) are the most common, accounting for 30 % of deaths from respiratory diseases. Most of these deaths occur after 65 years. Male mortality rates are three times higher than for women. The risk factors involved in these diseases, particularly for COPD, may explain the differences between the sexes. COPD are mainly associated with smoking, which is more common among men, but also with work-related risks (mining, steel making or farming). The regional differences in mortality from chronic respiratory diseases are very marked.

See Eurostat Atlas of Mortality: respiratory diseasespdf