The association of spirometric small airways obstruction with respiratory symptoms, cardiometabolic diseases, and quality of life: results from the Burden of Obstructive Lung Disease (BOLD) study.

BACKGROUND: Spirometric small airways obstruction (SAO) is common in the general population. Whether spirometric SAO is associated with respiratory symptoms, cardiometabolic diseases, and quality of life (QoL) is unknown. METHODS: Using data from the Burden of Obstructive Lung Disease study (N = 21,594), we defined spirometric SAO as the mean forced expiratory flow rate between 25 and 75% of the FVC (FEF25-75) less than the lower limit of normal (LLN) or the forced expiratory volume in 3 s to FVC ratio (FEV3/FVC) less than the LLN. We analysed data on respiratory symptoms, cardiometabolic diseases, and QoL collected using standardised questionnaires. We assessed the associations with spirometric SAO using multivariable regression models, and pooled site estimates using random effects meta-analysis. We conducted identical analyses for isolated spirometric SAO (i.e. with FEV1/FVC ≥ LLN). RESULTS: Almost a fifth of the participants had spirometric SAO (19% for FEF25-75; 17% for FEV3/FVC). Using FEF25-75, spirometric SAO was associated with dyspnoea (OR = 2.16, 95% CI 1.77-2.70), chronic cough (OR = 2.56, 95% CI 2.08-3.15), chronic phlegm (OR = 2.29, 95% CI 1.77-4.05), wheeze (OR = 2.87, 95% CI 2.50-3.40) and cardiovascular disease (OR = 1.30, 95% CI 1.11-1.52), but not hypertension or diabetes. Spirometric SAO was associated with worse physical and mental QoL. These associations were similar for FEV3/FVC. Isolated spirometric SAO (10% for FEF25-75; 6% for FEV3/FVC), was also associated with respiratory symptoms and cardiovascular disease. CONCLUSION: Spirometric SAO is associated with respiratory symptoms, cardiovascular disease, and QoL. Consideration should be given to the measurement of FEF25-75 and FEV3/FVC, in addition to traditional spirometry parameters.

Race and Ethnicity in Pulmonary Function Test Interpretation: An Official American Thoracic Society Statement.

Current American Thoracic Society (ATS) standards promote the use of race and ethnicity-specific reference equations for pulmonary function test (PFT) interpretation. There is rising concern that the use of race and ethnicity in PFT interpretation contributes to a false view of fixed differences between races and may mask the effects of differential exposures. This use of race and ethnicity may contribute to health disparities by norming differences in pulmonary function. In the United States and globally, race serves as a social construct that is based on appearance and reflects social values, structures, and practices. Classification of people into racial and ethnic groups differs geographically and temporally. These considerations challenge the notion that racial and ethnic categories have biological meaning and question the use of race in PFT interpretation. The ATS convened a diverse group of clinicians and investigators for a workshop in 2021 to evaluate the use of race and ethnicity in PFT interpretation. Review of evidence published since then that challenges current practice and continued discussion concluded with a recommendation to replace race and ethnicity-specific equations with race-neutral average reference equations, which must be accompanied with a broader re-evaluation of how PFTs are used to make clinical, employment, and insurance decisions. There was also a call to engage key stakeholders not represented in this workshop and a statement of caution regarding the uncertain effects and potential harms of this change. Other recommendations include continued research and education to understand the impact of the change, to improve the evidence for the use of PFTs in general, and to identify modifiable risk factors for reduced pulmonary function.

Use of Low-Cost Particle Counters for Cotton Dust Exposure Assessment in Textile Mills in Low- and Middle-Income Countries.

OBJECTIVE: There is a lack of consensus on methods for cotton dust measurement in the textile industry, and techniques vary between countries-relying mostly on cumbersome, traditional approaches. We undertook comparisons of standard, gravimetric methods with low-cost optical particle counters for personal and area dust measurements in textile mills in Pakistan. METHODS: We included male textile workers from the weaving sections of seven cotton mills in Karachi. We used the Institute of Occupational Medicine (IOM) sampler with a Casella Apex 2 standard pump and the Purple Air (PA-II-SD) for measuring personal exposures to inhalable airborne particles (n = 31). We used the Dylos DC1700 particle counter, in addition to the two above, for area-level measurements (n = 29). RESULTS: There were no significant correlations between the IOM and PA for personal dust measurements using the original (r = -0.15, P = 0.4) or log-transformed data (r = -0.32, P = 0.07). Similarly, there were no significant correlations when comparing the IOM with either of the particle counters (PA and Dylos) for area dust measurements, using the original (r = -0.07, P = 0.7; r = 0.10, P = 0.6) or log-transformed data (r = -0.09, P = 0.6; r = 0.07, P = 0.7). CONCLUSION: Our findings show a lack of correlation between the gravimetric method and the use of particle counters in both personal and area measurements of cotton dust, precluding their use for measuring occupational exposures to airborne dust in textile mills. There continues to be a need to develop low-cost instruments to help textile industries in low- and middle-income countries to perform cotton dust exposure assessment.

Prevalence and burden of chronic bronchitis symptoms: results from the BOLD study.

We studied the prevalence, burden and potential risk factors for chronic bronchitis symptoms in the Burden of Obstructive Lung Disease study.Representative population-based samples of adults aged ≥40 years were selected in participating sites. Participants completed questionnaires and spirometry. Chronic bronchitis symptoms were defined as chronic cough and phlegm on most days for ≥3 months each year for ≥2 years.Data from 24 855 subjects from 33 sites in 29 countries were analysed. There were significant differences in the prevalence of self-reported symptoms meeting our definition of chronic bronchitis across sites, from 10.8% in Lexington (KY, USA), to 0% in Ile-Ife (Nigeria) and Blantyre (Malawi). Older age, less education, current smoking, occupational exposure to fumes, self-reported diagnosis of asthma or lung cancer and family history of chronic lung disease were all associated with increased risk of chronic bronchitis. Chronic bronchitis symptoms were associated with worse lung function, more dyspnoea, increased risk of respiratory exacerbations and reduced quality of life, independent of the presence of other lung diseases.The prevalence of chronic bronchitis symptoms varied widely across the studied sites. Chronic bronchitis symptoms were associated with significant burden both in individuals with chronic airflow obstruction and those with normal lung function.

Chronic respiratory disease - the acceptable epidemic?

Chronic obstructive pulmonary disease (COPD) is a major cause of disability and death in the UK but is an even greater problem in low income countries. It is assumed by many to be almost entirely attributed to smoking. However, smoking alone cannot account for the distribution of the disease in the world and there is accumulating evidence that the disease is overwhelmingly a disease of poverty. The size of the problem and the failure of current hypotheses to explain the distribution of chronic lung disease make the lack of funding in this area surprising. The failure of science funders to respond to the analysis of the Cooksey report, which pointed out the extreme discrepancy between the size of the problem and the paucity of research funding, represents a serious failure in science policy. The lack of urgency in the face of such a large burden of illness suggests a degree of complacency in the face of a disease that is overwhelmingly a disease of the poor.

Development of an international scale of socio-economic position based on household assets.

BACKGROUND: The importance of studying associations between socio-economic position and health has often been highlighted. Previous studies have linked the prevalence and severity of lung disease with national wealth and with socio-economic position within some countries but there has been no systematic evaluation of the association between lung function and poverty at the individual level on a global scale. The BOLD study has collected data on lung function for individuals in a wide range of countries, however a barrier to relating this to personal socio-economic position is the need for a suitable measure to compare individuals within and between countries. In this paper we test a method for assessing socio-economic position based on the scalability of a set of durable assets (Mokken scaling), and compare its usefulness across countries of varying gross national income per capita. RESULTS: Ten out of 15 candidate asset questions included in the questionnaire were found to form a Mokken type scale closely associated with GNI per capita (Spearman's rank rs = 0.91, p = 0.002). The same set of assets conformed to a scale in 7 out of the 8 countries, the remaining country being Saudi Arabia where most respondents owned most of the assets. There was good consistency in the rank ordering of ownership of the assets in the different countries (Cronbach's alpha = 0.96). Scores on the Mokken scale were highly correlated with scores developed using principal component analysis (rs = 0.977). CONCLUSIONS: Mokken scaling is a potentially valuable tool for uncovering links between disease and socio-economic position within and between countries. It provides an alternative to currently used methods such as principal component analysis for combining personal asset data to give an indication of individuals' relative wealth. Relative strengths of the Mokken scale method were considered to be ease of interpretation, adaptability for comparison with other datasets, and reliability of imputation for even quite large proportions of missing values.

Burden of asthma and chronic obstructive pulmonary disease and access to essential medicines in low-income and middle-income countries.

Demographic and epidemiological transitions are changing the age structure of the population and the most common diseases. Non-communicable respiratory diseases are an increasing problem at both ends of the age range in low-income and middle-income countries. In children, who represent a large proportion of the total population, the increasing problem of asthma is a strain on health services. Improved survival of the older population is increasing the proportion of morbidity and mortality attributable to chronic lung diseases. Health services in low-resource countries are poorly adapted to treating chronic diseases. Designed to respond episodically to acute disease, almost all historical investment has focused on infectious diseases. Crucial to the successful management of chronic diseases is an infrastructure designed to support pro-active management, providing not only an accurate diagnosis, but also a secure supply of cost effective drugs at an affordable price. The absence of such an infrastructure in many countries and the market failure that makes drugs generally more expensive in low-resource regions means that many people with chronic non-communicable lung diseases are not given effective treatment. This has damaging economic consequences. The common causes of poor lung health in low-income countries are not the same as those in richer countries, and there is a need to study why they are so common and how best to manage them.

Remembering the forgotten non-communicable diseases.

The forthcoming post-Millennium Development Goals era will bring about new challenges in global health. Low- and middle-income countries will have to contend with a dual burden of infectious and non-communicable diseases (NCDs). Some of these NCDs, such as neoplasms, COPD, cardiovascular diseases and diabetes, cause much health loss worldwide and are already widely recognised as doing so. However, 55% of the global NCD burden arises from other NCDs, which tend to be ignored in terms of premature mortality and quality of life reduction. Here, experts in some of these 'forgotten NCDs' review the clinical impact of these diseases along with the consequences of their ignoring their medical importance, and discuss ways in which they can be given higher global health priority in order to decrease the growing burden of disease and disability.

Prevalence of COPD and tobacco smoking in Tunisia--results from the BOLD study.

In Tunisia, there is a paucity of population-based data on Chronic Obstructive Pulmonary Disease (COPD) prevalence. To address this problem, we estimated the prevalence of COPD following the Burden of Lung Disease Initiative. We surveyed 807 adults aged 40+ years and have collected information on respiratory history and symptoms, risk factors for COPD and quality of life. Post-bronchodilator spirometry was performed and COPD and its stages were defined according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. Six hundred and sixty one (661) subjects were included in the final analysis. The prevalence of GOLD Stage I and II or higher COPD were 7.8% and 4.2%, respectively (Lower Limit of Normal modified stage I and II or higher COPD prevalence were 5.3% and 3.8%, respectively). COPD was more common in subjects aged 70+ years and in those with a BMI < 20 kg/m2. Prevalence of stage I+ COPD was 2.3% in <10 pack years smoked and 16.1% in 20+ pack years smoked. Only 3.5% of participants reported doctor-diagnosed COPD. In this Tunisian population, the prevalence of COPD is higher than reported before and higher than self-reported doctor-diagnosed COPD. In subjects with COPD, age is a much more powerful predictor of lung function than smoking.

UK health performance: findings of the Global Burden of Disease Study 2010.

BACKGROUND: The UK has had universal free health care and public health programmes for more than six decades. Several policy initiatives and structural reforms of the health system have been undertaken. Health expenditure has increased substantially since 1990, albeit from relatively low levels compared with other countries. We used data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) to examine the patterns of health loss in the UK, the leading preventable risks that explain some of these patterns, and how UK outcomes compare with a set of comparable countries in the European Union and elsewhere in 1990 and 2010. METHODS: We used results of GBD 2010 for 1990 and 2010 for the UK and 18 other comparator nations (the original 15 members of the European Union, Australia, Canada, Norway, and the USA; henceforth EU15+). We present analyses of trends and relative performance for mortality, causes of death, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE). We present results for 259 diseases and injuries and for 67 risk factors or clusters of risk factors relevant to the UK. We assessed the UK's rank for age-standardised YLLs and DALYs for their leading causes compared with EU15+ in 1990 and 2010. We estimated 95% uncertainty intervals (UIs) for all measures. FINDINGS: For both mortality and disability, overall health has improved substantially in absolute terms in the UK from 1990 to 2010. Life expectancy in the UK increased by 4·2 years (95% UI 4·2-4·3) from 1990 to 2010. However, the UK performed significantly worse than the EU15+ for age-standardised death rates, age-standardised YLL rates, and life expectancy in 1990, and its relative position had worsened by 2010. Although in most age groups, there have been reductions in age-specific mortality, for men aged 30-34 years, mortality rates have hardly changed (reduction of 3·7%, 95% UI 2·7-4·9). In terms of premature mortality, worsening ranks are most notable for men and women aged 20-54 years. For all age groups, the contributions of Alzheimer's disease (increase of 137%, 16-277), cirrhosis (65%, ?15 to 107), and drug use disorders (577%, 71-942) to premature mortality rose from 1990 to 2010. In 2010, compared with EU15+, the UK had significantly lower rates of age-standardised YLLs for road injury, diabetes, liver cancer, and chronic kidney disease, but significantly greater rates for ischaemic heart disease, chronic obstructive pulmonary disease, lower respiratory infections, breast cancer, other cardiovascular and circulatory disorders, oesophageal cancer, preterm birth complications, congenital anomalies, and aortic aneurysm. Because YLDs per person by age and sex have not changed substantially from 1990 to 2010 but age-specific mortality has been falling, the importance of chronic disability is rising. The major causes of YLDs in 2010 were mental and behavioural disorders (including substance abuse; 21·5% [95 UI 17·2-26·3] of YLDs), and musculoskeletal disorders (30·5% [25·5-35·7]). The leading risk factor in the UK was tobacco (11·8% [10·5-13·3] of DALYs), followed by increased blood pressure (9·0 % [7·5-10·5]), and high body-mass index (8·6% [7·4-9·8]). Diet and physical inactivity accounted for 14·3% (95% UI 12·8-15·9) of UK DALYs in 2010. INTERPRETATION: The performance of the UK in terms of premature mortality is persistently and significantly below the mean of EU15+ and requires additional concerted action. Further progress in premature mortality from several major causes, such as cardiovascular diseases and cancers, will probably require improved public health, prevention, early intervention, and treatment activities. The growing burden of disability, particularly from mental disorders, substance use, musculoskeletal disorders, and falls deserves an integrated and strategic response. FUNDING: Bill & Melinda Gates Foundation.

Health sector costs of self-reported food allergy in Europe: a patient-based cost of illness study.

INTRODUCTION: Food allergy is a recognized health problem, but little has been reported on its cost for health services. The EuroPrevall project was a European study investigating the patterns, prevalence and socio-economic cost of food allergy. AIMS: To investigate the health service cost for food-allergic Europeans and the relationship between severity and cost of illness. METHODS: Participants recruited through EuroPrevall studies in a case-control study in four countries, and cases only in five countries, completed a validated economics questionnaire. Individuals with possible food allergy were identified by clinical history, and those with food-specific immunoglobulin E were defined as having probable allergy. Data on resource use were used to estimate total health care costs of illness. Mean costs were compared in the case-control cohorts. Regression analysis was conducted on cases from all 9 countries to assess impact of country, severity and age group. RESULTS: Food-allergic individuals had higher health care costs than controls. The mean annual cost of health care was international dollars (I$)2016 for food-allergic adults and I$1089 for controls, a difference of I$927 (95% confidence interval I$324-I$1530). A similar result was found for adults in each country, and for children, and was not sensitive to baseline demographic differences. Cost was significantly related to severity of illness in cases in nine countries. CONCLUSIONS: Food allergy is associated with higher health care costs. Severity of allergic symptoms is a key explanatory factor.

Case-finding options for COPD: results from the Burden of Obstructive Lung Disease study.

This study aimed to compare strategies for chronic obstructive pulmonary disease (COPD) case finding using data from the Burden of Obstructive Lung Disease study. Population-based samples of adults aged ≥40 yrs (n = 9,390) from 14 countries completed a questionnaire and spirometry. We compared the screening efficiency of differently staged algorithms that used questionnaire data and/or peak expiratory flow (PEF) data to identify persons at risk for COPD and, hence, needing confirmatory spirometry. Separate algorithms were fitted for moderate/severe COPD and for severe COPD. We estimated the cost of each algorithm in 1,000 people. For moderate/severe COPD, use of questionnaire data alone permitted high sensitivity (97%) but required confirmatory spirometry in 80% of participants. Use of PEF necessitated confirmatory spirometry in only 19-22% of subjects, with 83-84% sensitivity. For severe COPD, use of PEF achieved 91-93% sensitivity, requiring confirmatory spirometry in <9% of participants. Cost analysis suggested that a staged screening algorithm using only PEF initially, followed by confirmatory spirometry as needed, was the most cost-effective case-finding strategy. Our results support the use of PEF as a simple, cost-effective initial screening tool for conducting COPD case-finding in adults aged ≥40 yrs. These findings should be validated in real-world settings such as the primary care environment.

Assessment of allergen sensitization in a general population-based survey (European Community Respiratory Health Survey I).

PURPOSE: Exposed to a common environment, the IgE-mediated immune response differs, for instance, among sensitized subjects, some of them reacting toward one allergen (monosensitized) whereas others are sensitized to a wide array of allergens (polysensitized). However, a better phenotypic characterization is needed for epidemiologic studies. Using the data collected during the ECRHS I (European Community Respiratory Health Survey), several assessments of skin prick tests and serum-specific IgE to identify mono- and polysensitized patients were compared. METHODS: Subjects took part in the ECRHS-I. The CAP-System was used for serum allergen-specific IgE, and allergen-coated Phazet was used for prick tests. Four allergens (Dermatophagoides pteronyssinus, cat, timothy grass, and Cladosporium) were measured using IgE and nine (the same ones plus olive pollen, birch, Alternaria, Parietaria, and ragweed) were skin tested. One to two local allergens were also tested, depending on countries. RESULTS: Prevalence of sensitization in 11,355 subjects (34.0 [27.9-40.1] years, 49.9% men) ranged from 32.3% (four specific IgE, 19.3% mono- and 13.0% polysensitized) to 41.8% (four specific IgE combined to nine prick tests, 19.6% mono- and 22.2% polysensitized). Concordance between four specific IgE and four prick tests was weak (weighted κ 0.65 [0.64-0.66]). Concordance between seven and nine prick tests was high (weighted κ 0.99 [0.98-1.00]). Local allergens induced small changes in the prevalence of sensitization, and reclassified some subjects from mono- to polysensitized. CONCLUSIONS: Skin tests or serum-specific IgE may be chosen to identify allergenic sensitivity, mono- and polysensitized subjects without being strictly interchangeable.

The serum bank of EuroPrevall - the prevalence, cost and basis of food allergy across Europe.

EuroPrevall is an EU-funded multidisciplinary project including 62 institutions from 22 countries. EuroPrevall studies the prevalence and distribution of food allergies in infants, children, adolescents, and adults in Europe, threshold doses for allergenic foods, the role of the environment in food allergy, the socioeconomic impact of food allergy, and novel diagnostic tools for food allergies. The EuroPrevall serum bank (EPASB), containing samples from approximately 70,000 subjects, is a major tool to achieve these goals. EPASB is coordinated by the Paul-Ehrlich-Institut, Langen, Germany. Local sera collections are administered at the University of Amsterdam (NL), the University Hospital of Manchester (UK), Charité Hospital (DE) and the Paul-Ehrlich-Institut. The EPASB coordinator and managing partners distribute samples for experimental work and regulate access. The overall aim is to provide sera to fulfil EuroPrevall research goals. The EPASB coordinator and managing partners suggest appropriate sera for addressing specific scientific and diagnostic questions. The serum bank will be maintained after termination of the project, but subsequent investigations must be in accordance with the original research goals of EuroPrevall. Thus, the contributors of the sera retain control over their future use. This rule prevents investigation of questions outside the scope of EuroPrevall, e.g. the allergenicity of genetically-modified foods.

The Burden of Obstructive Lung Disease Initiative (BOLD): rationale and design.

Quantifying COPD prevalence worldwide is needed to document COPD's effect on disability, health care costs, and impaired quality of life and to inform governments and health planners. As an adjunct to data obtained from population-based studies, and for countries where a fully powered prevalence survey cannot be done, modeling of COPD prevalence and its economic burdens can help estimate potential health care needs and costs. For comparability, standardized methods for prevalence surveys are needed that can be used in countries at all levels of economic development. The Burden of Obstructive Lung Disease (BOLD) Initiative has developed a set of methods for estimating COPD prevalence and a model for assessing its economic impact, and piloted these methods in China and Turkey. The methods were revised to reflect the findings in the pilot studies, and BOLD is now making the standardized methods available worldwide. The BOLD Operations Center provides training, materials, quality control, and data analysis. BOLD emphasizes data quality control at every stage of the process. Data from paper forms completed in the field are entered electronically to a specially designed secure Web platform. Pre- and post-bronchodilator spirometry testing is done on all participants, and all spirometry data are reviewed for quality. Questionnaires are used to obtain information about respiratory symptoms, health status, exposure to risk factors, and economic data about the burden of COPD. BOLD's standardized methods will provide a uniform way to compare COPD burden within and between countries, and where differences are found, to explore explanations for these differences.