Prevalence of chronic cough, its risk factors and population attributable risk in the Burden of Obstructive Lung Disease (BOLD) study: a multinational cross-sectional study

© 2024 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)Background: Chronic cough is a common respiratory symptom with an impact on daily activities and quality of life. Global prevalence data are scarce and derive mainly from European and Asian countries and studies with outcomes other than chronic cough. In this study, we aimed to estimate the prevalence of chronic cough across a large number of study sites as well as to identify its main risk factors using a standardised protocol and definition. Methods: We analysed cross-sectional data from 33,983 adults (≥40 years), recruited between Jan 2, 2003 and Dec 26, 2016, in 41 sites (34 countries) from the Burden of Obstructive Lung Disease (BOLD) study. We estimated the prevalence of chronic cough for each site accounting for sampling design. To identify risk factors, we conducted multivariable logistic regression analysis within each site and then pooled estimates using random-effects meta-analysis. We also calculated the population attributable risk (PAR) associated with each of the identifed risk factors. Findings: The prevalence of chronic cough varied from 3% in India (rural Pune) to 24% in the United States of America (Lexington,KY). Chronic cough was more common among females, both current and passive smokers, those working in a dusty job, those with a history of tuberculosis, those who were obese, those with a low level of education and those with hypertension or airflow limitation. The most influential risk factors were current smoking and working in a dusty job. Interpretation: Our findings suggested that the prevalence of chronic cough varies widely across sites in different world regions. Cigarette smoking and exposure to dust in the workplace are its major risk factors.info:eu-repo/semantics/publishedVersio

Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

Background Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. Methods We analysed cross-sectional data from 28 823 adults (≥40 years) in 34 countries. We considered 11 occupations and grouped them by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)/FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income. Results Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR 1.52, 95% CI 1.19–1.94), wheeze (OR 1.37, 95% CI 1.16–1.63) and dyspnoea (OR 1.83, 95% CI 1.53–2.20), but not lower FVC (β=0.02 L, 95% CI −0.02–0.06 L) or lower FEV1/FVC (β=0.04%, 95% CI −0.49–0.58%). Some findings differed by sex and gross national income. Conclusion At a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they are associated with more respiratory symptoms. Because not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries.publishedVersio

Prevalence of chronic cough, its risk factors and population attributable risk in the Burden of Obstructive Lung Disease (BOLD) study: a multinational cross-sectional study

Background: Chronic cough is a common respiratory symptom with an impact on daily activities and quality of life. Global prevalence data are scarce and derive mainly from European and Asian countries and studies with outcomes other than chronic cough. In this study, we aimed to estimate the prevalence of chronic cough across a large number of study sites as well as to identify its main risk factors using a standardized protocol and definition. Methods: We analyzed cross-sectional data from 33,983 adults (≥40 years), recruited between Jan 2, 2003 and Dec 26, 2016, in 41 sites (34 countries) from the Burden of Obstructive Lung Disease (BOLD) study. We estimated the prevalence of chronic cough for each site accounting for sampling design. To identify risk factors, we conducted multivariable logistic regression analysis within each site and then pooled estimates using random-effects meta-analysis. We also calculated the population-attributable risk (PAR) associated with each of the identified risk factors. Findings: The prevalence of chronic cough varied from 3% in India (rural Pune) to 24% in the United States of America (Lexington, KY). Chronic cough was more common among females, both current and passive smokers, those working in a dusty job, those with a history of tuberculosis, those who were obese, those with a low level of education, and those with hypertension or airflow limitation. The most influential risk factors were current smoking and working in a dusty job. Interpretation: Our findings suggested that the prevalence of chronic cough varies widely across sites in different world regions. Cigarette smoking and exposure to dust in the workplace are its major risk factors.info:eu-repo/semantics/publishedVersio

Cohort Profile: Burden of Obstructive Lung Disease (BOLD) study

The Burden of Obstructive Lung Disease (BOLD) study was established to assess the prevalence of chronic airflow obstruction, a key characteristic of chronic obstructive pulmonary disease, and its risk factors in adults (≥40 years) from general populations across the world. The baseline study was conducted between 2003 and 2016, in 41 sites across Africa, Asia, Europe, North America, the Caribbean and Oceania, and collected high-quality pre- and post-bronchodilator spirometry from 28 828 participants. The follow-up study was conducted between 2019 and 2021, in 18 sites across Africa, Asia, Europe and the Caribbean. At baseline, there were in these sites 12 502 participants with high-quality spirometry. A total of 6452 were followed up, with 5936 completing the study core questionnaire. Of these, 4044 also provided high-quality pre- and post-bronchodilator spirometry. On both occasions, the core questionnaire covered information on respiratory symptoms, doctor diagnoses, health care use, medication use and ealth status, as well as potential risk factors. Information on occupation, environmental exposures and diet was also collected

Variations in elderly peoples’ visits to the emergency departments in Iceland: A five-year population study

To access publisher's full text version of this article click on the hyperlink belowINTRODUCTION: Elderly people visiting emergency departments (ED) are a non-homogenous group. Gender and other socio-demographic variations in emergency care might be present. However, gender-specific ED-data is scarce. METHODS: We retrieved retrospective data on all ED-visits, by 67years and older from 2008 to 2012, and calculated incidence of visits applying population registries. The relationship of age-categories, marital status, health and residence with outcomes were analyzed descriptively by Chi-square tests. Regression models were built to analyze gender-specific variations. RESULTS: Of the total ED-visits, 20% were from the elderly population (n=66,141), at a mean 3.1 visits per individual. Men (n=30.269) had higher incidence of visits in all age-categories. They were mostly married (69%) and women widowed (43%), although the incidence of partnered visitors underrepresented population-data while widowed and single living overrepresented. Women had more often co-morbidities, their most common causes of visits were musculoskeletal (20%) and men circulatory causes (14%). Men were more likely to be admitted (OR: 1.23; 95% CI 1.16-1.30) and had more unplanned ED-revisits (HR: 1.20; 95% CI 1.06-1.35) within 30 days. DISCUSSION: Elderly men visiting the ED were more often married than women. Gender differences were found in causes of visits and outcomes. In clinical practice, gender may be considered when identifying risk and planning adequate care related elderly ED-visits.Nursing Association Research fund Landspitali University Hospital Science Fund Icelandic Geriatric Association Research Fun

Hip fractures among older people in Iceland between 2008 and 2012.

To access publisher's full text version of this article click on the hyperlink belowHip fractures are a serious injury especially among older people, mainly caused by falls and women have a higher risk. The authors studied gender differences in hip fractures, marital status, waiting times for surgery and mortality in an older population. Data was obtained for all 67 years and older admitted with hip fractures to an Emergency Department (ED) in Iceland 2008-2012. The associations of covariates with mortality were analyzed using multivariable logistic regression. The study included 1053 patients; covering 80% of hip fractures in Iceland during the study period, 72% were women. Men were more often married (51% vs. 23%) (P < 0.001). Average waiting time was men vs. women 21.5 h/18.9 h (p = 0.003). Mortality within 12 months was men 36% vs. women 21% (Odds Ratio (OR); 2.30, 95% Confidence Interval (CI); 1.66-3.18). Higher mortality rates were observed in older age-groups compared to 67-79 years old, i.e.80-89 years: OR 1.80 (95% CI 1.25-2.60) and 90-109 years: OR 4.52 (95% CI 2.91-7.01). Waiting time was not associated with 12-months mortality risk after adjustment. Although women constitute the majority of elderly with hip fractures, men had higher mortality in our study. Further reserach that examine factors affecting gender difference will likey be of benefit and associated changes to the care already dleivered in the ED may improve mortality.Nursing Association Research fund Landspitali University Hospital Science Fun

Humoral Immune Response to SARS-CoV-2 in Iceland.

To access publisher's full text version of this article click on the hyperlink belowBackground: Little is known about the nature and durability of the humoral immune response to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: We measured antibodies in serum samples from 30,576 persons in Iceland, using six assays (including two pan-immunoglobulin [pan-Ig] assays), and we determined that the appropriate measure of seropositivity was a positive result with both pan-Ig assays. We tested 2102 samples collected from 1237 persons up to 4 months after diagnosis by a quantitative polymerase-chain-reaction (qPCR) assay. We measured antibodies in 4222 quarantined persons who had been exposed to SARS-CoV-2 and in 23,452 persons not known to have been exposed. Results: Of the 1797 persons who had recovered from SARS-CoV-2 infection, 1107 of the 1215 who were tested (91.1%) were seropositive; antiviral antibody titers assayed by two pan-Ig assays increased during 2 months after diagnosis by qPCR and remained on a plateau for the remainder of the study. Of quarantined persons, 2.3% were seropositive; of those with unknown exposure, 0.3% were positive. We estimate that 0.9% of Icelanders were infected with SARS-CoV-2 and that the infection was fatal in 0.3%. We also estimate that 56% of all SARS-CoV-2 infections in Iceland had been diagnosed with qPCR, 14% had occurred in quarantined persons who had not been tested with qPCR (or who had not received a positive result, if tested), and 30% had occurred in persons outside quarantine and not tested with qPCR. Conclusions: Our results indicate that antiviral antibodies against SARS-CoV-2 did not decline within 4 months after diagnosis. We estimate that the risk of death from infection was 0.3% and that 44% of persons infected with SARS-CoV-2 in Iceland were not diagnosed by qPCR

Overdiagnosis of COPD in subjects with unobstructed spirometry

Background: There are several reports on the underdiagnosis of COPD, while little is known about COPD overdiagnosis and overtreatment. We describe the overdiagnosis and the prevalence of spirometrically defined false-positive COPD, as well as their relationship with overtreatment across 23 population samples in 20 countries participating in the BOLD Study between 2003 and 2012. Methods: A false-positive diagnosis of COPD was considered when participants reported a doctor's diagnosis of COPD, but postbronchodilator spirometry was unobstructed (FEV1/FVC > LLN). Additional analyses were performed using the fixed ratio criterion (FEV1/FVC < 0.7). Results: Among 16,177 participants, 919 (5.7%) reported a previous medical diagnosis of COPD. Postbronchodilator spirometry was unobstructed in 569 subjects (61.9%): false-positive COPD. A similar rate of overdiagnosis was seen when using the fixed ratio criterion (55.3%). In a subgroup analysis excluding participants who reported a diagnosis of "chronic bronchitis" or "emphysema" (n = 220), 37.7% had no airflow limitation. The site-specific prevalence of false-positive COPD varied greatly, from 1.9% in low- to middle-income countries to 4.9% in high-income countries. In multivariate analysis, overdiagnosis was more common among women, and was associated with higher education; former and current smoking; the presence of wheeze, cough, and phlegm; and concomitant medical diagnosis of asthma or heart disease. Among the subjects with false-positive COPD, 45.7% reported current use of respiratory medication. Excluding patients with reported asthma, 34.4% of those with normal spirometry still used a respiratory medication. Conclusions: False-positive COPD is frequent. This might expose nonobstructed subjects to possible adverse effects of respiratory medication.info:eu-repo/semantics/publishedVersio

COPD: should diagnosis match physiology?

We are very grateful to Dr. Vanfleteren and colleagues for commenting on our data regarding overdiagnosed COPD2 and for putting this evidence into the framework of the current understanding of the disease. Based on the data presented on overdiagnosis, and on prior Burden of Obstructive Lung Disease (BOLD) observations on underdiagnosis,3 we truly believe that our worldwide community of pulmonary specialists could do much better in caring for this extremely prevalent and devastating disease. Overall, our data indicate that for one patient with a “matched” COPD diagnosis (ie, the presence of postbronchodilator airways obstruction and a positive recall of such a diagnosis), there is always another “mismatched,” false-positive patient with COPD. This patient possibly experiences all the untoward consequences, such as receiving expensive and possibly harmful medication, and missing chances for treatment of cardiac disease or asthma. On the contrary, for each “known” patient with COPD who has a poorly reversible airway obstruction, there are four to five other patients out there with yet undetected airways obstruction. Again, we are missing opportunities in these patients for smoking intervention, symptom relief, and prolongation of their lives.info:eu-repo/semantics/publishedVersio