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 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.

Funding

Wellcome Trust.

Prevalence and Population Attributable Risk for Chronic Airflow Obstruction in a Large Multinational Study

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.

Is the flap reinforcement of the bronchial stump really necessary to prevent bronchial fistula?

Background/aim

The development of bronchopleural fistula (BPF) remains the most severe complication of lung resection, especially after pneumonectomy. Studies provide controversial reports regarding the benefits of flap reinforcement of the bronchial stump (FRBS) in preventing BPF’s occurrence.

Methods

This is a retrospective cohort study of 558 patients that underwent lung resection in a 12-year period (from 2007 to 2018). Ninety patients (16.1%) underwent pneumonectomy. Patient follow-up period varied from 1 to 12 years.

Results

Out of 558 patients in this study, 468 (83.9%) underwent lobectomy, and the remnant underwent pneumonectomy. In 114 cases with lobectomy, only 24.4% had FRBS, meanwhile in 56 cases with pneumonectomy only 62.2% had FRBS. BPF occurred in 8 patients with lobectomy (1.7%) and in 10 patients with pneumonectomy (11.1%). Among cases with post-pneumonectomy BPF, 6 (10.7%) had FRBS performed, while no FRBS was performed among patients with post-lobectomy BPF, although these data weren’t statistically (p > 0.05). In 24 patients (20 lobectomies and 4 pneumonectomies) with lung cancer (10.4%) neoadjuvant treatment was performed, in which 20 patients underwent chemotherapy and 4 underwent radiotherapy. FRBS was applied in each of the above 24 operative cases, but only in 4 of them the BPF was verified.

Conclusion

The idea of enhancing the blood supply through the FRBS for BPF prevention has gain traction. Although FRBS has been identified as valuable and effective method in BPF prevention following lung resection, our study results did not support this evidence.

Peculiar features of the Mycobacterium tuberculosis population structure in Albania

Albania is a Balkan country with moderate to low incidence of tuberculosis (TB) and very low prevalence of drug resistant TB. Here, we analyzed a country-wide multi-year Mycobacterium tuberculosis collection in order to detect possible dynamic trends of TB in Albania, with a focus on drug resistance and endemic/epidemic clones. In total, 743 isolates collected in 2007 to 2011 were divided into 107 spoligotypes and 351 MIRU-types. Based on the MIRU-VNTR phylogenetic analysis, the isolates were assigned to the following lineages/families: animal ecotypes (5 M. bovis and 2 M. caprae isolates), Lineage 2 (5 Beijing isolates), Lineage 3 (1 CAS-Delhi isolate) and, mostly and overwhelmingly, Lineage 4 (Cameroon, Uganda, Ghana and related; NEW-1-related; Ural, Haarlem, LAM, S, TUR; and unclassified isolates). Most of the isolates (452/743) were intermediately located on the global VNTR tree and did not cluster with any reference profile; they were distantly related to different families within Lineage 4 and we designated them as "unclassified L4" isolates. The significantly higher proportion of drug resistance was observed in (i) Beijing genotype compared to all other isolates (60%, P = .008), (ii) "unclassified L4" compared to all other isolates (13.9%, P = .04) and (iii) SIT2936 compared to other "unclassified L4" (34.3%, P = .0006). Analysis of the yearly collections revealed (i) some decrease of the large heterogeneous "unclassified L4" from 65% to 57%; (ii) steadily increasing gradient of LAM from 3.4 to 13.3%; (iii) stable prevalence of Haarlem (15-20%); and (iv) decrease of TUR with only 1.1% in 2011. Most of the LAM (33/49) and Beijing (3/5) isolates belonged to the VNTR types specific for Russia and former Soviet Union countries. To conclude, our results highlight a peculiar nature of M. tuberculosis population in Albania that is dominated by local and unclassified genotypes within Lineage 4, and also features European genotypes and epidemically relevant clones originating from the former Soviet Union countries. At the same time, these imported clones remain drug susceptible and prevalence of drug resistance on a whole is low.

Surgical Management of Concurrent Partial Anomalous Pulmonary Venous Return and Lung Cancer of the Same Lobe

Partial anomalous pulmonary venous return (PAPVR) is a rare congenital left-to-right shunt where pulmonary veins drain into systemic circulation. This is a presentation of the case of a patient with concurrent PAPVR and adenocarcinoma of the same lobe. The pulmonary veins of right upper lobe drained into superior vena cava (SVC), whereas the middle and lower lobes veins drained into the left atrium as two distinct vessels. Surgeons should always perform a diligent search for anomalous vascular structure using computed tomographic (CT) angiography prior to surgery. In our case, surgical approach was "safe" because both pathologies developed in the same lobe.

Gender Related Differences in Reported Respiratory Symptoms

Background: Physiological research on dyspnea has provided some information on how sex differences in lung and airway size can influence the experience of dyspnea during exercise; however, there is still a knowledge gap with regard to sex-related differences in other respiratory symptoms, including cough and sputum production. Objective: The objective of this analysis was to assess sex related differences in reported objective symptoms using data from the population-based Burden of Obstructive Lung Disease (BOLD) study in Albania. Method: Males and females with impaired lung function may experience the same symptoms but per-ceive and/or report them differently. In this analysis were included 997 responders who had completed the core questionnaire, which included data on respiratory symptoms using the following questions: “Do you usually cough when you don’t have a cold?” and “Do you usually bring up phlegm from your chest, or do you usually have phlegm in your chest that is difficult to bring up when you don’t have a cold. Chronic was defined as three months or more per year. Data used were drawn from the final report for Albania provided by BOLD team. Results: Overall, male gender was associated with increased odds for reported chronic cough at any group age [Total: 14.7 (2.3) vs. 6.6 (0.9)]. This difference is very much reduced in the group age 70+ years old [25.8 (8.2) vs. 21.3 (6.8)]. In the contrary when we used the estimated population preva-lence of chronic cough by pack-years and gender, female gender was associated with increased odds for reported chronic cough especially in the 10+ pack-years groups [50.4 (11.0) vs. 12.2 (8.3) in 10-20 pack-years and 29.0 (5.5) vs. 26.0 (3.3) 20+ pack-years] indicating a increased smoking susceptibility of female gender. In contrast, female gender was associated with decreased odds for reported phlegm. Even for the same pack-years of smoking, female gender is associated with decreased odds for report-ed chronic phlegm [0 vs. 7.1 (8.6) in 10-20 pack-years group; 0 vs. 15.4 (3.0) in 20+ pack-years group]. Conclusions: Physicians need to recognize that although a female may not report chronic sputum or phlegm production and a male may not report chronic cough, a diagnosis of Chronic Obstructive Pulmonary Disease should still be considered as symptoms often are the first step to a diagnosis of under-lying airway disease.

Evaluation of Mycobacterium tuberculosis viability in OMNIgene-SPUTUM reagent upon multi-day transport at ambient temperature

Background

Maintaining the quality of clinical specimens for tuberculosis (TB) testing is a major challenge in many high TB burden-limited resources countries. Sample referral systems in low and middle income countries are often weak and the maintenance of the cold-chain challenging and very costly for TB programs. The development of transport media allowing the preservation of samples without refrigeration is critical for increasing access to TB diagnostic services and for reducing the costs related to testing.

Methods

We evaluated the performance of OMNIgene-SPUTUM (OM-S) reagent for the maintenance of Mycobacterium tuberculosis (MTB) viability in sputum samples in the absence of refrigeration and its capacity to stabilize nucleic acid for molecular testing. A total of 329 sputum specimens from presumptive TB cases collected at the National Reference Laboratory in Tirana, Albania, were either decontaminated by a conventional method or processed with OM-S reagent and stored at room temperature. Samples in OM-S were shipped to the Supranational Reference Laboratory in Milan, Italy, at various times and processed for liquid culture.

Results

Our data show that OM-S maintains MTB viability for at least three weeks in the absence of refrigeration and improves the quality of culture resulting in a contamination rate lower than 0.5%. However, a significant delay in the time to culture positivity was observed for samples stored for more than two weeks in OM-S.

Conclusions

Overall, OM-S offers multiple benefits both at laboratory and TB national program level by increasing the availability to quality diagnostics, promoting access to health care services and strengthening TB patient care especially in hard to reach populations.

The association between chronic airflow obstruction and poverty in 12 sites of the multinational BOLD study

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.

Results of a tuberculin skin testing survey in Albania

Introduction: Tuberculosis affected about 8.5 million patients in 2011. Numerous efforts are needed to reduce the pool of individuals with latent TB infection (LTBI). The aim of the study was to describe a tuberculin skin testing (TST) survey carried out in Albania to estimate the LTBI burden; furthermore, knowledge of TB was evaluated through an ad hoc questionnaire. Methodology: A TST survey was performed in three geographical districts of Albania: Tirana-Kamez, Vlora, and Dibra. Cluster sampling was carried out of young Albanian students. In addition, the same students were given a questionnaire to assess their knowledge, attitudes, and any misconceptions about TB. The mean (standard deviation) age of the individuals, according to their educational level, was the following: grade five, 11.03 (0.18) years; grade six, 12.02 (0.17) years; and grade seven, 13.02 (0.16) years. Results: The TST induration size was read in 4,648 students. About 5.0% showed a reaction >5 mm, with a significant variability in the districts selected (12.1% in the district of Dibra). An induration diameter >15 mm was found mainly in those areas with high TB incidence (i.e., Tirana-Kamez and Dibra). About 13% of the students had no knowledge of TB. Conclusion: LTBI prevalent cases are estimated to be low in Albania, although there are areas where the TB management should be improved to reduce the probability of Mycobacterium tuberculosis transmission. The level of knowledge about TB disease is inadequate and new public health strategies should be implemented, focusing on educational TV programs.

Tuberculosis Incidence and Case Notification Rates in Kosovo and the Balkans in 2012: Cross-country Comparison

Aim:

Tuberculosis (TB) continues to be a considerable burden especially for millions of young adults and disadvantaged people worldwide. The TB incidence and notification rates are good indicators of TB situation in a country. Our aim was to compare TB incidence and notification rates in Kosovo and in seven other Balkan countries.

Methods:

Retrospective epidemiologic analysis of published data on TB incidence and notification rates in eight Balkan countries in 2012. Notification rates were expressed per 100,000 inhabitants and were calculated based on the number of TB cases reported divided by the population of each country under analysis.

Results:

The TB incidence in Kosovo (47/100,000) was considerably higher compared to its four neighboring countries: Albania (16/100,000), Macedonia, Montenegro (18/100,000) and Serbia (23/100,000). The TB notification rates in Kosovo and other countries closely mimicked the incidence rates in these countries.

Conclusion:

The exceptionally high TB incidence rate in Kosovo could be due to many factors including low health and medical-seeking behaviors of the local population, poverty and low education levels. Effective interventions should be adapted to the local context in order to increase the chances of success.

A six-month study of pulmonary cancer in Albanian women

Lung cancer is a potentially lethal disease, whose prevalence in Albania is constantly increasing, especially in women. Early diagnosis is extremely important with regard to life expectancy and quality. The authors conducted a survey on the behaviour in a sample group of Albanian women diagnosed with primary and secondary lung cancers. A discussion upon diagnostic methods, smoking habits, histological type, Karnofsky performance status (KPS), and treatment modalities is made. The data collected by the authors suggest that nonsmokers formed the main group of lung cancer female patients. The most frequent histological type was adenocarcinoma. Mesothelioma was the most frequent of the secondary pulmonary lung cancers, followed from metastasizing breast cancer. Despite a generally good performance of the cases, the diagnosis of pulmonary cancer is delayed. The data collected could not find a convincing etiological role of tobacco smoking, but caution is needed, regarding the short time length of the study and the sustained number of participants.

TB situation in Albania, 2001-2008

SETTING

Albania, population 3.4 million.

OBJECTIVE

To describe DOTS (directly observed treatment-short course chemotherapy) implementation, treatment outcomes and epidemiological situation in Albania from 2001 to 2008.

DESIGN

DOTS strategy was introduced in 2001 and gradually expanded. A retrospective analysis of treatment outcomes and epidemiological data on TB patients was analyzed for this period.

RESULTS

DOTS was expanded to 76% of the country in 2008. Treatment success among new smear-positive patients ranged from 82% in 2001 to 86% in 2007. The incidence of TB in Albania decreased from 17 per 100,000 inhabitants in 2001 to 12/100,000 in 2008 and estimated case detection for smear positive cases improved from 42% in 2001 to 75% in 2007.

CONCLUSIONS

The TB incidence has fallen progressively since DOTS was initiated. Treatment outcome was better in DOTS areas compared to Non-DOTS areas and overall treatment outcome was improved during DOTS implementation. Despite gradually, DOTS was successfully implemented and full expansion is necessary.