21 results found
Burney P, Patel J, Minelli C, et al., 2021, Prevalence and population attributable risk for chronic airflow obstruction in a large multinational study, American Journal of Respiratory and Critical Care Medicine, Vol: 203, Pages: 1353-1365, ISSN: 1073-449X
Rationale: The Global Burden of Disease programme identified smoking, and ambient and household air pollution as the main drivers of death and disability from Chronic Obstructive Pulmonary Disease (COPD). Objective: To estimate the attributable risk of chronic airflow obstruction (CAO), a quantifiable characteristic of COPD, due to several risk factors. Methods: The Burden of Obstructive Lung Disease study is a cross-sectional study of adults, aged≥40, in a globally distributed sample of 41 urban and rural sites. Based on data from 28,459 participants, we estimated the prevalence of CAO, defined as a post-bronchodilator one-second forced expiratory volume to forced vital capacity ratio < lower limit of normal, and the relative risks associated with different risk factors. Local RR were estimated using a Bayesian hierarchical model borrowing information from across sites. From these RR and the prevalence of risk factors, we estimated local Population Attributable Risks (PAR). Measurements and Main Results: Mean prevalence of CAO was 11.2% in men and 8.6% in women. Mean PAR for smoking was 5.1% in men and 2.2% in women. The next most influential risk factors were poor education levels, working in a dusty job for ≥10 years, low body mass index (BMI), and a history of tuberculosis. The risk of CAO attributable to the different risk factors varied across sites. Conclusions: While smoking remains the most important risk factor for CAO, in some areas poor education, low BMI and passive smoking are of greater importance. Dusty occupations and tuberculosis are important risk factors at some sites.
Amaral A, Burney P, Patel J, et al., 2021, Chronic airflow obstruction and ambient particulate air pollution, Thorax, ISSN: 0040-6376
Smoking is the most well-established cause of chronic airflow obstruction (CAO) but particulate air pollution and poverty have also been implicated. We regressed sex-specific prevalence of CAO from 41 Burden of Obstructive Lung Disease study sites against smoking prevalence from the same study, the gross national income per capita and the local annual mean level of ambient particulate matter (PM2.5) using negative binomial regression. The prevalence of CAO was not independently associated with PM2.5 but was strongly associated with smoking and was also associated with poverty. Strengthening tobacco control and improved understanding of the link between CAO and poverty should be prioritised.
Amaral AFS, Patel J, Buist AS, et al., 2020, Risk factors for low forced vital capacity in the multinational BOLD study: An update, Publisher: EUROPEAN RESPIRATORY SOC JOURNALS LTD, ISSN: 0903-1936
Burney P, Atassi M, Kava A, et al., 2020, Association between chronic airflow obstruction and socio-economic position in Morocco: BOLD results., International Journal of Tuberculosis and Lung Disease, Vol: 24, Pages: 202-206, ISSN: 1027-3719
Objective. Chronic Obstructive Lung Disease (COPD) is the third most common cause of death in the world. Other factors than smoking could be involved in the development of COPD such as socio-economic status. The aim of this study was to investigate the association between chronic airflow obstruction and socio-economic status in Morocco. Design. In the BOLD (Burden of Obstructive Lung Disease) study carried out in Fez Morocco, questionnaires and spirometry tests were performed. Socio-economic status was evaluated using a wealth score (0-10) based on household assets. The forced expiratory volume in 1s (FEV1)/ forced vital capacity (FVC) ratio was used to measure airflow obstruction. Results. In total, 760 subjects were included in the analysis. The mean age was 55.3 years (SD=10.2); the wealth score was on average 7.54 (SD=1.63). After controlling for other factors and potential confounders, the FEV1/ FVC increased by 0.4% (95% CI: 0.01, 0.78; p<0.04) per unit increase in wealth score. Aging, tobacco-smoking, underweight, history of tuberculosis and asthma were also independently associated with a higher risk of airflow obstruction. Conclusion. Our findings suggest that airflow obstruction is associated with poverty in Morocco. Further investigations are needed to better understand the mechanisms of this association.
Burney P, Patel J, 2019, Variation in "normal values" of forced vital capacity (FVC) and ratio of one-second Forced Expiratory Volume (FEV1)/FVC between 42 Burden of Obstructive Lung Disease (BOLD) sites, European-Respiratory-Society (ERS) International Congress, Publisher: EUROPEAN RESPIRATORY SOC JOURNALS LTD, ISSN: 0903-1936
Janson C, Malinovschi A, Amaral A, et al., 2019, Bronchodilator reversibility in asthma and COPD: Findings from three large population studies, European Respiratory Journal, Vol: 54, ISSN: 0903-1936
Bronchodilator response (BDR) testing is used as a diagnostic method in obstructive airway diseases. The aim of this investigation was to compare different methods for measuring BDR in participants with asthma and COPD and to study to the extent to which BDR was related to symptom burden and phenotypic characteristics.Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) was measured before and 15 min after 200 μg of salbutamol in 35 628 subjects aged 16 years and older from three large international population studies. The subjects were categorised in three groups: current asthma (n=2833), COPD (n=1146), and no airway disease (n=31 649). Three definitions for flow related (increase in FEV1) and three for volume related (increase in FVC) were used.The prevalence of bronchodilator reversibility expressed as increase FEV1≥12% and 200 mL was 17.3% and 18.4% in participants with asthma and COPD, respectively, while the corresponding prevalence was 5.1% in those with no airway disease. In asthma, bronchodilator reversibility was associated with wheeze (OR (95% CI): 1.36 (1.04–1.79)), atopy (OR 1.36 (1.04–1.79)) and higher FeNO while in COPD neither flow nor volume related bronchodilator reversibility was associated with symptom burden, exacerbations or health status after adjusting for prebronchodilator FEV1.Bronchodilator reversibility was at least as common in participants with COPD as those with asthma. This indicates that measures of reversibility are of limited value for distinguishing asthma from COPD in population studies. In asthma, however, bronchodilator reversibility may be a phenotypic marker.
Burney PGJ, Patel J, Minelli C, 2018, THE POPULATION ATTRIBUTABLE RISKS (PAR) FOR CHRONIC AIRFLOW OBSTRUCTION (CAO) IN 40 CENTRES WORLDWIDE, Winter Meeting of the British-Thoracic-Society, Publisher: BMJ PUBLISHING GROUP, Pages: A247-A248, ISSN: 0040-6376
Burney P, Patel J, Minelli C, 2018, Late Breaking Abstract - The population attributable risks (PAR) for chronic airflow obstruction (CAO) in 40 BOLD study centres worldwide., 28th International Congress of the European-Respiratory-Society (ERS), Publisher: EUROPEAN RESPIRATORY SOC JOURNALS LTD, ISSN: 0903-1936
Amaral AFS, Patel J, Kato BS, et al., 2018, Airflow obstruction and use of solid fuels for cooking or heating: BOLD results, American Journal of Respiratory and Critical Care Medicine, Vol: 197, Pages: 595-610, ISSN: 1073-449X
Rationale: Evidence supporting the association of COPD or airflow obstruction with use of solid fuels is conflicting and inconsistent. Objective: To assess the association of airflow obstruction with self-reported use of solid fuels for cooking or heating. Methods: We analysed 18,554 adults from the BOLD study, who had provided acceptable post-bronchodilator spirometry measurements and information on use of solid fuels. The association of airflow obstruction with use of solid fuels for cooking or heating was assessed by sex, within each site, using regression analysis. Estimates were stratified by national income and meta-analysed. We carried out similar analyses for spirometric restriction, chronic cough and chronic phlegm. Measurements and main results: We found no association between airflow obstruction and use of solid fuels for cooking or heating (ORmen=1.20, 95%CI 0.94-1.53; ORwomen=0.88, 95%CI 0.67-1.15). This was true for low/middle and high income sites. Among never smokers there was also no evidence of an association of airflow obstruction with use of solid fuels (ORmen=1.00, 95%CI 0.57-1.76; ORwomen=1.00, 95%CI 0.76-1.32). Overall, we found no association of spirometric restriction, chronic cough or chronic phlegm with the use of solid fuels. However, we found that chronic phlegm was more likely to be reported among female never smokers and those who had been exposed for ≥20 years. Conclusion: Airflow obstruction assessed from post-bronchodilator spirometry was not associated with use of solid fuels for cooking or heating.
Saad N, Patel JH, Minelli C, et al., 2017, Explaining ethnic disparities in lung function among young adults: a pilot investigation, PLOS One, Vol: 12, ISSN: 1932-6203
BackgroundEthnic disparities in lung function have been linked mainly to anthropometric factors but have not been fully explained. We conducted a cross-sectional pilot study to investigate how best to study ethnic differences in lung function in young adults and evaluate whether these could be explained by birth weight and socio-economic factors.MethodsWe recruited 112 university students of White and South Asian British ethnicity, measured post-bronchodilator lung function, obtained information on respiratory symptoms and socio-economic factors through questionnaires, and acquired birth weight through data linkage. We regressed lung function against ethnicity and candidate predictors defined a priori using linear regression, and used penalised regression to examine a wider range of factors. We reviewed the implications of our findings for the feasibility of a larger study.ResultsThere was a similar parental socio-economic environment and no difference in birth weight between the two ethnic groups, but the ethnic difference in FVC adjusted for sex, age, height, demi-span, father’s occupation, birth weight, maternal educational attainment and maternal upbringing was 0.81L (95%CI: -1.01 to -0.54L). Difference in body proportions did not explain the ethnic differences although parental immigration was an important predictor of FVC independent of ethnic group. Participants were comfortable with study procedures and we were able to link birth weight data to clinical measurements.ConclusionStudies of ethnic disparities in lung function among young adults are feasible. Future studies should recruit a socially more diverse sample and investigate the role of markers of acculturation in explaining such differences.
Townend J, Minelli C, Mortimer K, et al., 2017, The association between chronic airflow obstruction and poverty in 12 sites from the multinational BOLD study, European Respiratory Journal, Vol: 49, ISSN: 1399-3003
Poverty is strongly associated with mortality from COPD, but little is known of its relation to airflow obstruction.In a cross-sectional study of adults aged ≥40 years from 12 sites (N=9255), participating in the Burden of Obstructive Lung Disease (BOLD) study, poverty was evaluated using a wealth score (0–10) based on household assets. Obstruction, measured as forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) (%) after administration of 200 μg salbutamol, and prevalence of FEV1/FVC<lower limit of normal were tested for association with poverty for each site, and the results were combined by meta-analysis.Mean wealth scores ranged from 4 in Blantyre (Malawi) and Kashmir (India) to 10 in Riyadh (Saudi Arabia), and the prevalence of obstruction, from 16% in Kashmir to 3% in Riyadh and Penang (Malaysia). Following adjustments for age and sex, FEV1/FVC increased by 0.36% (absolute change) (95%CI: 0.22, 0.49; p<0.001) per unit increase in wealth score. Adjustments for other confounders reduced this effect to 0.23% (0.11, 0.34), but even this value remained highly significant (p<0.001). Results were consistent across sites (I2=1%; phet=0.44). Mean wealth scores explained 38% of the variation in mean FEV1/FVC between sites (r2=0.385, p=0.031).Airflow obstruction is consistently associated with poverty at individual and community levels across several countries.
Saad NJ, Patel J, Burney P, et al., 2017, Birth Weight and Lung Function in Adulthood: A Systematic Review and Meta-analysis., Annals of the American Thoracic Society, Vol: 14, Pages: 994-1004, ISSN: 2329-6933
RATIONALE: There is evidence suggesting that birth weight may influence lung function in adulthood, but it is unclear whether it might differentially affect restrictive (FVC) and obstructive (FEV1/FVC) patterns. OBJECTIVES: To summarize evidence available on the association of birth weight, weight at 1 year, and weight gain in the first year of life with FVC and FEV1/FVC in adulthood. METHODS: We performed a systematic review of the literature by searching MEDLINE, EMBASE, and Web of Science through January 2015. Data were combined using inverse-variance weighted meta-analysis with random effects models and between-study heterogeneity evaluated. We conducted a priori subgroup or sensitivity analyses by age, country wealth, ethnicity, sex, and smoking. We evaluated risk of bias using the Newcastle Ottawa Scale and reporting bias using funnel plots. RESULTS: Eighteen articles were included in the review and 13 in the meta-analyses. Most studies were from high-income countries, and all had a low risk of bias. We found strong evidence of an association of birth weight with adult FVC, a 59.4 ml higher FVC in adulthood per kilogram increase in birth weight (95% confidence interval, 43.3-75.5), with no evidence of heterogeneity. Evidence of an association of birth weight with FEV1/FVC was weaker and showed some inconsistency across studies. Only one study investigated weight at 1 year, and another one reported weight gain in the first year. CONCLUSIONS: Our meta-analyses show strong and consistent evidence of an association of birth weight with adult FVC, a measure of restrictive impairment, with much weaker evidence for airflow obstruction.
Koul PA, Hakim NA, Malik SA, et al., 2016, Prevalence of Chronic airflow limitation in Kashmir, North India: Results from the BOLD study., International Journal of Tuberculosis and Lung Disease, Vol: 20, Pages: 1399-1404, ISSN: 1815-7920
BACKGROUND: Data on spirometrically defined chronic airflow limitation (CAL) are scarce in developing countries.OBJECTIVE: To estimate the prevalence of spirometrically defined CAL in Kashmir, North India.METHODS: Using Burden of Obstructive Lung Disease survey methods, we administered questionnaires to randomly selected adults aged 40 years. Post-bronchodilator spirometry was performed to estimate the prevalence of CAL and its relation to potential risk factors.RESULTS: Of 1100 participants initially recruited, 953 (86.9%) responded and 757 completed acceptable spirometry and questionnaires. The prevalence of a forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) ratio less than the lower limit of normal was 17.3% (4.5) in males and 14.8% (2.1) in females. Risk factors for CAL included higher age, cooking with wood and lower educational status. The prevalence of current smoking was 61% in males and 22% in females; most smoked hookahs. CAL was found equally in non-smoking males and females, and was independently associated with the use of the hookah, family history of respiratory disease and poor education. A self-reported doctor's diagnosis of chronic obstructive pulmonary disease was reported in 8.4/1000 (0.9% of females and 0.8% of males).CONCLUSION: Spirometrically confirmed CAL is highly prevalent in Indian Kashmir, and seems to be related to the high prevalence of smoking, predominantly in the form of hookah smoking.
Loh LC, Rashid A, Sholehah S, et al., 2016, Low prevalence of obstructive lung disease in a suburban population of Malaysia: A BOLD collaborative study, Respirology, Vol: 21, Pages: 1055-1061, ISSN: 1440-1843
Background and objectiveAs a Burden of Obstructive Lung Disease (BOLD) collaboration, we studied the prevalence of chronic obstructive pulmonary disease (COPD) and its associated risk factors in a suburban population in Malaysia.MethodsNonhospitalized men or women of age ≥ 40 years from a Penang district were recruited by stratified simple random sampling. Participants completed detailed questionnaires on respiratory symptoms and exposure to COPD risk factors. Prebronchodilator and post-bronchodilator spirometry conducted was standardized across all international BOLD sites in device and data quality control.ResultsOf the 1218 individuals recruited for the study, 663 (340 men and 323 women) had complete questionnaire data and acceptable post-bronchodilator spirometry. The estimated population prevalence of Global Initiative for Chronic Obstructive Lung Disease (GOLD) ≥ stage I was 6.5% or 3.4% based on either fixed forced expiratory volume in 1 s/forced vital capacity ratio of <0.7 or National Health and Nutritional Examination Survey-derived lower limit of normal ratio while the prevalence of GOLD ≥ stage II was either 4.6% or 3.1%, respectively. Multivariate logistic regression analysis showed independent association between all stages of COPD with cigarette smoking pack years (adjusted odds ratio per 10-year increase: 1.73; 95% confidence interval: 1.09–2.75), use of biomass fuel for cooking (1.61; 1.10–2.36) and exposure to dusty job (1.50; 1.09–2.06).ConclusionThis study represented the first robust population-based epidemiology data on COPD for Malaysia. Compared with other sites globally, our estimated population prevalence was relatively low. In addition to cigarette smoking, use of biomass fuel and exposure to dusty job represented significant risk to the development of COPD.
Loh LC, Rashid A, Sholehah S, et al., 2015, LOW PREVALENCE OF OBSTRUCTIVE LUNG DISEASE IN A SUBURBAN POPULATION OF MALAYSIA: A BOLD COLLABORATIVE STUDY, RESPIROLOGY, Vol: 20, Pages: 54-54, ISSN: 1323-7799
Amaral AFS, Patel J, Gnatiuc L, et al., 2015, Association of pulse wave velocity with total lung capacity: A cross-sectional analysis of the BOLD London study, Respiratory Medicine, ISSN: 1532-3064
BackgroundLow lung function, measured using spirometry, has been associated with mortality from cardiovascular disease, but whether this is explained by airflow obstruction or restriction is a question that remains unanswered.ObjectivesTo assess the association of total lung capacity (TLC), forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) with several cardio-metabolic and inflammatory markers.MethodsIn the follow up of the Burden of Lung Disease (BOLD) study in London, acceptable post-bronchodilator spirometric, pulse rate, pulse wave velocity and blood pressure data were obtained from 108 participants. Blood samples for measurement of cardio-metabolic and inflammatory markers were also collected from these participants. Association of lung function and volume with the different biomarkers was examined in multivariable linear regression models adjusted for potential confounders.ResultsFollowing adjustment for age, sex, height, and ethnicity, TLC (adjusted coefficient = −1.53; 95% CI: −2.57, −0.49) and FVC (adjusted coefficient = −2.66; 95% CI: −4.98, −0.34) were inversely associated with pulse wave velocity, and further adjustment for smoking status, pack-years and body mass index (BMI) did not materially change these results. FEV1 was inversely associated with systolic blood pressure, and adjustment for smoking status, pack-years and BMI made this association stronger (adjusted coefficient = −9.47; 95% CI: −15.62, −3.32).ConclusionThe inverse association of pulse wave velocity, which is a marker of cardiovascular disease, with TLC suggests that the association of the former with low FVC is independent of airflow obstruction. The association between FEV1 with systolic blood pressure after adjustment for FVC suggests an association with airflow obstruction rather than with restricted spirometry.
Townend J, Minelli C, Harrabi I, et al., 2015, Development of an international scale of socio-economic position based on household assets., Emerg Themes Epidemiol, Vol: 12, Pages: 13-13
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 w
Mortimer K, Azhar H, Patel J, et al., 2015, The burden of non-communicable lung disease in urban Malawi, Publisher: EUROPEAN RESPIRATORY SOC JOURNALS LTD, ISSN: 0903-1936
Saad NJ, Patel J, Minelli C, et al., 2015, LATE-BREAKING ABSTRACT: Birth weight and lung function in later life: A systematic review & meta-analysis, Publisher: EUROPEAN RESPIRATORY SOC JOURNALS LTD, ISSN: 0903-1936
Burney PGJ, Patel J, Newson R, et al., 2015, Global and regional trends in COPD mortality, 1990-2010, European Respiratory Journal, Vol: 45, Pages: 1239-1247, ISSN: 0903-1936
Between 1990 and 2010, chronic obstructive pulmonary disease (COPD) moved from the fourth to third most common cause of death worldwide.Using data from the Global Burden of Disease programme we quantified regional changes in the number of COPD deaths and COPD mortality rates between 1990 and 2010. We estimated the proportion of the change that was attributable to gross national income per capita and an index of cumulative smoking exposure, and quantified the difference in mortality rates attributable to demographic changes.Despite a substantial decrease in COPD mortality rates, COPD deaths fell only slightly, from three million in 1990 to 2.8 million in 2010, because the mean age of the population increased. The number of COPD deaths in 2010 would have risen to 5.2 million if the age- and sex-specific mortality rates had remained constant. Changes in smoking led to only a small increase in age- and sex-specific mortality rates, which were strongly associated with changes in gross national income.The increased burden of COPD mortality was mainly driven by changes in age distribution, but age- and sex-specific rates fell as incomes rose. The rapid response to increasing affluence suggests that changes in COPD mortality are not entirely explained by changes in early life.
Entekume G, Patel J, Sivasubramaniam S, et al., 2011, Prevalence, Causes, and Risk Factors for Functional Low Vision in Nigeria: Results from the National Survey of Blindness and Visual Impairment, INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE, Vol: 52, Pages: 6714-6719, ISSN: 0146-0404
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