Full dataset for CAM manuscript (bmjopen-2013-003360.R1)

This dataset contains the complete information for the statistical analysis of this publication. The data were collected in the field. The titles of variables were self-explanary. For binary variables, "Yes" was commonly coded as 1 and "No" as 0. For the variable of asthma control ("Control"), "controlled" was coded as 0, "partially controlled" as 1 and "uncontrolled" as 2. "CAM_types" reported all different types of complementary and alternative asthma medicines which the patients received in the past 12 months

Population demographics and risk factors of individual sites and for whole cohort.

§<p>Doctor Diagnosis of AO = presence of self reported prior diagnosis of either ever-asthma, or asthmatic bronchitis, or allergic bronchitis, or COPD, or emphysema, or chronic bronchitis. Data for Age, BMI, Packyears, and Spirometry results are expressed in mean(SD); All others are expressed as % of group(SE) and are weighted to the local population. BMI = Body-mass index;</p>†<p>% predicted values = maximum values/predicted values(NHANES)*100;</p>*<p>One-Way ANOVA, alpha = 0.05;</p>#<p>Chi-Square Test.</p>&<p>post bronchodilator responses: % change in FEV1 or FVC after bronchodilator relative to pre-bronchodilator value.</p

Determinants of bronchodilator responsiveness in forced expiratory volume in one second as % pre-bronchodilator value [%ΔFEV1i] –results from univariate and multivariate analyses of the whole cohort.

*<p>Standard estimates allow comparison between variables with different units. It is the expected change in bronchodilator response per 1 SD increase in the variable. After multivariate correction for confounding variables the ‘most powerful’ effect on BDRFEV1 is doctor diagnosis of current-asthma, followed by age, ever-smoking, use of respiratory drugs (any medication for breathing including nasal decongestant), and gender.These values are adjusted for all corivariates including site and for the proportion of Caucasian population in each site.</p

Logistic regression analysis of cohort without self-reported diagnosis of ever-asthma, COPD/Chronic bronchitis/Emphysema (n = 3508) showing risk [adjusted Odds ratio & 95% confidence intervals] of Symptoms with increasing post-bronchodilator change in forced expiratory volume in 1 sec % pre-bronchodilator value (%ΔFEV1i).

*<p>Variables for the first Quintile were used as the reference;</p><p>#Slope for trend was statistically different from the horizontal. Odds ratios and 95% CI adjusted for age, BMI, gender, usage of respiratory drugs (any medication for breathing including nasal decongestant), ever-smoking, site, and porpotion of Caucasian.</p

Logistic regression analysis of cohort without self-reported diagnosis of ever-asthma, COPD/Chronic bronchitis/Emphysema (n = 3378) showing risk [adjusted Odds ratio & 95% confidence intervals] of Symptoms with increasing post-bronchodilator change in forced vital capacity as % Pre-bronchodilator value (%ΔFVCi).

*<p>Variables for the first Quintile were used as the reference;</p><p>#Slope for trend was statistically different from the horizontal. Odds ratios and 95% CI adjusted for age, BMI, gender, usage of respiratory drugs (any medication for breathing including nasal decongestant), ever-smoking, site, and proportion of Caucasian.</p

Findings on Thoracic Computed Tomography Scans and Respiratory Outcomes in Persons with and without Chronic Obstructive Pulmonary Disease: A Population-Based Cohort Study

<div><p>Background</p><p>Thoracic computed tomography (CT) scans are widely performed in clinical practice, often leading to detection of airway or parenchymal abnormalities in asymptomatic or minimally symptomatic individuals. However, clinical relevance of CT abnormalities is uncertain in the general population.</p><p>Methods</p><p>We evaluated data from 1361 participants aged ≥40 years from a Canadian prospective cohort comprising 408 healthy never-smokers, 502 healthy ever-smokers, and 451 individuals with spirometric evidence of chronic obstructive pulmonary disease (COPD) who had thoracic CT scans. CT images of subjects were visually scored for respiratory bronchiolitis(RB), emphysema(E), bronchial-wall thickening(BWT), expiratory air-trapping(AT), and bronchiectasis(B). Multivariable logistic regression models were used to assess associations of CT features with respiratory symptoms, dyspnea, health status as determined by COPD assessment test, and risk of clinically significant exacerbations during 12 months follow-up.</p><p>Results</p><p>About 11% of life-time never-smokers demonstrated emphysema on CT scans. Prevalence increased to 30% among smokers with normal lung function and 36%, 50%, and 57% among individuals with mild, moderate or severe/very severe COPD, respectively. Presence of emphysema on CT was associated with chronic cough (OR,2.11; 95%CI,1.4–3.18); chronic phlegm production (OR,1.87; 95% CI,1.27–2.76); wheeze (OR,1.61; 95% CI,1.05–2.48); dyspnoea (OR,2.90; 95% CI,1.41–5.98); CAT score≥10(OR,2.17; 95%CI,1.42–3.30) and risk of ≥2 exacerbations over 12 months (OR,2.17; 95% CI, 1.42–3.0).</p><p>Conclusions</p><p>Burden of thoracic CT abnormalities is high among Canadians ≥40 years of age, including never-smokers and smokers with normal lung function. Detection of emphysema on CT scans is associated with pulmonary symptoms and increased risk of exacerbations, independent of smoking or lung function.</p></div

Absolute Leukocyte Telomere Length in HIV-Infected and Uninfected Individuals: Evidence of Accelerated Cell Senescence in HIV-Associated Chronic Obstructive Pulmonary Disease

<div><p>Combination antiretroviral therapy (cART) has extended the longevity of human immunodeficiency virus (HIV)-infected individuals. However, this has resulted in greater awareness of age-associated diseases such as chronic obstructive pulmonary disease (COPD). Accelerated cellular senescence may be responsible, but its magnitude as measured by leukocyte telomere length is unknown and its relationship to HIV-associated COPD has not yet been established. We measured absolute telomere length (aTL) in peripheral leukocytes from 231 HIV-infected adults. Comparisons were made to 691 HIV-uninfected individuals from a population-based sample. Subject quartiles of aTL were assessed for relationships with measures of HIV disease severity, airflow obstruction, and emphysema severity on computed tomographic (CT) imaging. Multivariable regression models identified factors associated with shortened aTL. Compared to HIV-uninfected subjects, the mean aTL in HIV-infected patients was markedly shorter by 27 kbp/genome (p<0.001); however, the slopes of aTL vs. age were not different (p=0.469). Patients with longer known durations of HIV infection (p=0.019) and lower nadir CD4 cell counts (p=0.023) had shorter aTL. Shorter aTL were also associated with older age (p=0.026), smoking (p=0.005), reduced forced expiratory volume in one second (p=0.030), and worse CT emphysema severity score (p=0.049). HIV-infected subjects demonstrate advanced cellular aging, yet in a cART-treated cohort, the relationship between aTL and age appears no different from that of HIV-uninfected subjects.</p></div

Demographics, exposures, Clinical Characteristics, Pulmonary function and CT measurements of the study population stratified into five subgroups according to post bronchodilator spirometry (N = 1361).

<p>Demographics, exposures, Clinical Characteristics, Pulmonary function and CT measurements of the study population stratified into five subgroups according to post bronchodilator spirometry (N = 1361).</p

Prevalence of respiratory bronchiolitis; air-trapping; bronchial wall thickening; emphysema; bronchiectasis.

<p>Five study subgroups are: Normal (FEV₁/FVC ≥ LLN and never smoker); At Risk (FEV₁/FVC ≥ LLN and ever smoker); Mild COPD (FEV₁/FVC < LLN and FEV₁%Pred ≥ 80%); Moderate COPD (FEV₁/FVC < LLN and 50% ≤ FEV₁%Pred < 80%); Severe to very severe COPD (FEV₁/FVC < LLN and FEV₁%Pred < 50%). All P values are corrected by Holm-Bonferroni correction for multiple comparisons. P values<0.05: *ref = Normal; # Ref = At Risk; ϕ Ref = LLN Mild; θ Ref = LLN moderate.</p

The risk of visual CT variables on developing of patient-reported outcomes (data for Fig 2 in manuscript).

<p>The risk of visual CT variables on developing of patient-reported outcomes (data for <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0166745#pone.0166745.g002" target="_blank">Fig 2</a> in manuscript).</p