Ambient Air Pollution and Dysanapsis: Associations with Lung Function and Chronic Obstructive Pulmonary Disease in the Canadian Cohort Obstructive Lung Disease Study.

Rationale: Outdoor air pollution is a potential risk factor for lower lung function and chronic obstructive pulmonary disease (COPD). Little is known about how airway abnormalities and lung growth might modify this relationship. Objectives: To evaluate the associations of ambient air pollution exposure with lung function and COPD and examine possible interactions with dysanapsis. Methods: We made use of cross-sectional postbronchodilator spirometry data from 1,452 individuals enrolled in the CanCOLD (Canadian Cohort Obstructive Lung Disease) study with linked ambient fine particulate matter (PM2.5) and nitrogen dioxide (NO2) air pollution estimates. Dysanapsis, or the ratio of the airway-to-lung volume calculated from thoracic computed tomography images, was used to examine possible interactions. Measurements and Main Results: In adjusted models, 101.7 ml (95% confidence interval [CI], -166.2 to -37.2) and 115.0 ml (95% CI, -196.5 to -33.4) lower FEV1 were demonstrated per increase of 2.4 ug/m3 PM2.5 and 9.2 ppb NO2, respectively. Interaction between air pollution and dysanapsis was not statistically significant when modeling the airway-to-lung ratio as a continuous variable. However, a 109.8 ml (95% CI, -209.0 to -10.5] lower FEV1 and an 87% (95% CI, 12% to 213%) higher odds of COPD were observed among individuals in the lowest, relative to highest, airway-to-lung ratio, per 2.4 µg/m3 increment of PM2.5. Conclusions: Ambient air pollution exposure was associated with lower lung function, even at relatively low concentrations. Individuals with dysanaptic lung growth might be particularly susceptible to inhaled ambient air pollutants, especially those at the extremes of dysanapsis.

Dyspnoea and symptom burden in mild-moderate COPD: the Canadian Cohort Obstructive Lung Disease Study.

Studies assessing dyspnoea and health-related quality of life (HRQoL) in chronic obstructive pulmonary disease (COPD) have focussed on patients in clinical settings, not the general population. The aim of this analysis was to compare the prevalence and severity of dyspnoea and impaired HRQoL in individuals with and without COPD from the general population, focussing on mild-moderate COPD. Analysis of the 3-year Canadian Cohort Obstructive Lung Disease (CanCOLD) study included four subgroups: mild COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1); moderate COPD (GOLD 2); non-COPD smokers; and non-COPD never-smokers. The primary outcome was dyspnoea (Medical Research Council (MRC) scale), and the secondary outcome was HRQoL (COPD Assessment Test (CAT) score; Saint George's Respiratory Questionnaire (SGRQ) score). Subgroups were analysed by sex, physician-diagnosed COPD status and exacerbations. 1443 participants (mild COPD (n=397); moderate COPD (n=262(; smokers (n=449) and never-smokers (n=335)) were studied. People with mild COPD were more likely to report more severe dyspnoea (MRC 2 versus 1) than those without COPD (OR (95% CI) 1.42 (1.05-1.91)), and non-COPD never-smokers (OR (95%CI) 1.64 (1.07-2.52)). Among people with mild COPD, more severe dyspnoea was reported in women versus men (MRC2 versus 1; OR (95% CI) 3.70 (2.23-6.14)); people with, versus without, physician-diagnosed COPD (MRC2 versus 1; OR (95% CI) 3.27 (1.71-6.23)), and people with versus without recent exacerbations (MRC2 versus 1; ≥2 versus 0 exacerbations: OR (95% CI) 3.62 (1.02-12.86); MRC ≥3 versus 1; 1 versus 0 exacerbation: OR (95% CI): 9.24 (2.01-42.42)). Similar between-group differences were obtained for CAT and SGRQ scores. Careful assessment of dyspnoea and HRQoL could help identify individuals for earlier diagnosis and treatment.

High eosinophil counts predict decline in FEV1: results from the CanCOLD study.

INTRODUCTION: The aim of this study was to examine the association between blood eosinophil levels and the decline in lung function in individuals aged >40 years from the general population. METHODS: The study evaluated the eosinophil counts from thawed blood in 1120 participants (mean age 65 years) from the prospective population-based Canadian Cohort of Obstructive Lung Disease (CanCOLD) study. Participants answered interviewer-administered respiratory questionnaires and performed pre-/post-bronchodilator spirometric tests at 18-month intervals; computed tomography (CT) imaging was performed at baseline. Statistical analyses to describe the relationship between eosinophil levels and decline in forced expiratory volume in 1 s (FEV1) were performed using random mixed-effects regression models with adjustments for demographics, smoking, baseline FEV1, ever-asthma and history of exacerbations in the previous 12 months. CT measurements were compared between eosinophil subgroups using ANOVA. RESULTS: Participants who had a peripheral eosinophil count of ≥300 cells·µL-1 (n=273) had a greater decline in FEV1 compared with those with eosinophil counts of <150 cells·µL-1 (n=430; p=0.003) (reference group) and 150-<300 cells·µL-1 (n=417; p=0.003). The absolute change in FEV1 was -32.99 mL·year-1 for participants with eosinophil counts <150 cells·µL-1; -38.78 mL·year-1 for those with 150-<300 cells·µL-1 and -67.30 mL·year-1 for participants with ≥300 cells·µL-1. In COPD, higher eosinophil count was associated with quantitative CT measurements reflecting both small and large airway abnormalities. CONCLUSION: A blood eosinophil count of ≥300 cells·µL-1 is an independent risk factor for accelerated lung function decline in older adults and is related to undetected structural airway abnormalities.

The Burden of Illness Related to Chronic Obstructive Pulmonary Disease Exacerbations in Québec, Canada.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) prevalence in Canada has risen over time. COPD-related exacerbations contribute to the increased health care utilization (HCU) in this population. This study investigated the impact of exacerbations on COPD-related HCU. METHODS: This retrospective observational cohort study used patient data from the Québec provincial health insurance databases. Eligible patients with a new HCU claim with a diagnostic billing for COPD during 2001-2010 were followed until March 31, 2011. Exacerbation rates and time to first exacerbation were assessed. Unadjusted analyses and multivariable models compared the rate of HCU by exacerbation classification (any [moderate/severe], moderate, or severe). RESULTS: The exacerbation event rate in patients with an exacerbation was 34.3 events/100 patient-years (22.7 for moderate exacerbations and 11.6 for severe exacerbations). Median time to first exacerbation of any classification was 37 months. In unadjusted analyses, COPD-related HCU significantly increased with exacerbation severity. In the multivariable, HCU rates were significantly higher after exacerbation versus before exacerbation (p < 0.01) for patients with an exacerbation or moderate exacerbations. For severe exacerbations, general practitioner, respiratory specialist, emergency room, and hospital visits were significantly higher after exacerbation versus before exacerbation (p < 0.001). CONCLUSIONS: Exacerbations were associated with increased HCU, which was more pronounced for patients with severe exacerbations. Interventions to reduce the risk of exacerbations in patients with COPD may reduce disease burden.

Noncommunicable Lung Disease in Sub-Saharan Africa. A Community-based Cross-Sectional Study of Adults in Urban Malawi.

RATIONALE: Noncommunicable diseases are major causes of morbidity and mortality in sub-Saharan Africa (sSA). Valid burden of disease estimates are lacking for noncommunicable lung disease in sSA. OBJECTIVES: We performed a community-based survey to determine the prevalence of chronic lung disease among adults 18 years or older in Malawi, using American Thoracic Society standard spirometry, internationally validated respiratory symptom and exposure questionnaires, and an assessment of HIV status. METHODS: An age- and sex-stratified random sample of 2,000 adults was taken from the population of the Chilomoni district of Blantyre, Malawi. Fieldworkers collected questionnaire data, conducted HIV testing, and performed pre- and post-bronchodilator spirometry on eligible participants. Survey-weighted population prevalence estimates of respiratory symptoms and spirometric abnormalities were computed, and bivariate and multivariable regression were used to identify associated variables. MEASUREMENTS AND MAIN RESULTS: Questionnaire data, HIV status, and standard spirometry were obtained from 1,059, 933, and 749 participants, respectively. Current respiratory symptoms, exposure to biomass, and ever-smoking were reported by 11.8, 85.2, and 10.4% of participants, respectively. HIV prevalence was 24.2%. Moderate to severe airway obstruction was seen in 3.6%. The prevalence of spirometric restriction was 38.6% using National Health and Nutrition Examination Survey III reference ranges and 9.0% using local reference ranges. Age was positively associated with obstruction, whereas low body mass index was associated with restriction. CONCLUSIONS: More than 40% of the Malawian adults in our urban population sample had abnormal lung function (mostly restrictive) in the context of widespread exposure to biomass smoke and a high prevalence of HIV. These findings potentially have major public health implications for Malawi and the broader sSA region.

A cross-sectional study of household biomass fuel use among a periurban population in Malawi.

RATIONALE: The Global Burden of Disease Study suggests almost 3.5 million people die as a consequence of household air pollution every year. Respiratory diseases including chronic obstructive pulmonary disease and pneumonia in children are strongly associated with exposure to household air pollution. Smoke from burning biomass fuels for cooking, heating, and lighting is the main contributor to high household air pollution levels in low-income countries like Malawi. A greater understanding of biomass fuel use in Malawi should enable us to address household air pollution-associated communicable and noncommunicable diseases more effectively. OBJECTIVES: To conduct a cross-sectional analysis of biomass fuel use and population demographics among adults in Blantyre, Malawi. METHODS: We used global positioning system-enabled personal digital assistants to collect data on location, age, sex, marital status, education, occupation, and fuel use. We describe these data and explore associations between demographics and reported fuel type. MEASUREMENTS AND MAIN RESULTS: A total of 16,079 adults participated (nine households refused); median age was 30 years, there was a similar distribution of men and women, 60% were married, and 62% received secondary school education. The most commonly reported occupation for men and women was "salaried employment" (40.7%) and "petty trader and marketing" (23.5%), respectively. Charcoal (81.5% of households), wood (36.5%), and electricity (29.1%) were the main fuels used at home. Only 3.9% of households used electricity exclusively. Lower educational and occupational attainment was associated with greater use of wood. CONCLUSIONS: This large cross-sectional study has identified extensive use of biomass fuels in a typical sub-Saharan Africa periurban population in which women and people of lower socioeconomic status are disproportionately affected. Biomass fuel use is likely to be a major driver of existing communicable respiratory disease and the emerging noncommunicable disease (especially respiratory and cardiovascular) epidemic in this region. Our data will help inform the rationale for specific intervention studies and the development of appropriately targeted public health strategies to tackle this important and poverty-related global health problem.

Increased risk of exacerbation and hospitalization in subjects with an overlap phenotype: COPD-asthma.

BACKGROUND: Several COPD phenotypes have been described; the COPD-asthma overlap is one of the most recognized. The aim of this study was to evaluate the prevalence of three subgroups (asthma, COPD, and COPD-asthma overlap) in the Latin American Project for the Investigation of Obstructive Lung Disease (PLATINO) study population, to describe their main characteristics, and to determine the association of the COPD-asthma overlap group with exacerbations, hospitalizations, limitations due to physical health, and perception of general health status (GHS). METHODS: The PLATINO study is a multicenter population-based survey carried out in five Latin American cities. Outcomes were self-reported exacerbations (defined by deterioration of breathing symptoms that affected usual daily activities or caused missed work), hospitalizations due to exacerbations, physical health limitations, and patients' perception of their GHS obtained by questionnaire. Subjects were classified in three specific groups: COPD--a postbronchodilator (post-BD) FEV1/FVC ratio of < 0.70; asthma--presence of wheezing in the last year and a minimum post-BD increase in FEV1 or FVC of 12% and 200 mL; and overlap COPD-asthma--the combination of the two. RESULTS: Out of 5,044 subjects, 767 were classified as having COPD (12%), asthma (1.7%), and COPD-asthma overlap (1.8%). Subjects with COPD-asthma overlap had more respiratory symptoms, had worse lung function, used more respiratory medication, had more hospitalization and exacerbations, and had worse GHS. After adjusting for confounders, the COPD-asthma overlap was associated with higher risks for exacerbations (prevalence ratio [PR], 2.11; 95% CI, 1.08-4.12), hospitalizations (PR, 4.11; 95% CI, 1.45-11.67), and worse GHS (PR, 1.47; 95% CI, 1.18-1.85) compared with those with COPD. CONCLUSIONS: The coexisting COPD-asthma phenotype is possibly associated with increased disease severity.

Characteristics of a COPD population categorised using the GOLD framework by health status and exacerbations.

GOLD proposed a COPD assessment framework focussed on symptoms measured by the COPD Assessment Test™ (CAT) or the mMRC and on exacerbation risk based on poor lung function (FEV1 <50%) or a history of ≥2 exacerbations in the previous year. This analysis examined the characteristics of COPD patients recruited from routine clinical settings and classified using the GOLD framework. 1041 European COPD patients (38.5% from primary care) from the Adelphi Respiratory Disease Specific Programme with information on CAT, mMRC, spirometry and exacerbation history in the previous year were analysed. Their mean age was 64.9 ± 9.9 years and mean FEV1 was 62.5 ± 17.8% predicted; 80% were in GOLD 2 spirometric grade or milder. CAT and mMRC cut points identified different groups of patients; using CAT, the composition was: Group A 9.3%, Group B 48.5%, Group C 0.7% and Group D 41.5%. 80% were classified as high risk based on exacerbation history and 25% of patients in a low risk category (GOLD A and B) had 1 exacerbation in the previous year. The incidence of diabetes, hypertension and hyperlipidaemia rose with worsening GOLD group (all p < 0.0001); diabetes GOLD A 4%, GOLD B 16%, GOLD D 29%; hypertension GOLD A 38%, GOLD B 55%, GOLD D 65%; hyperlipidaemia GOLD A 13%, GOLD B 30%, GOLD D 37%. In patients seen in routine clinical settings, 25% of GOLD low risk patients had one exacerbation per year and the incidence of cardio-vascular and metabolic diseases increases with worsening GOLD group.

An integrated analysis of the efficacy of fluticasone furoate nasal spray versus placebo on the nasal symptoms of perennial allergic rhinitis.

Intranasal corticosteroids are widely prescribed for the treatment of perennial allergic rhinitis (PAR). The aim of this analysis was to determine whether the beneficial effects of once-daily (q.d.) fluticasone furoate nasal spray (FFNS) effectively improved individual nasal symptoms of PAR. An integrated analysis was performed on data from three randomized, double-blind, placebo-controlled, parallel-group trials designed to evaluate the efficacy and safety of FFNS at 110 micrograms, q.d. in subjects with PAR. The analysis included 460 subjects who received FFNS and 459 who received placebo for 4 weeks. All subjects evaluated the severity of individual nasal symptoms of nasal congestion, nasal itching, rhinorrhea, and sneezing on a four-point categorical scale. The main efficacy measures included change from baseline in daily reflective total nasal symptom score (rTNSS), reflective daily scores for each individual symptom, and predose instantaneous TNSS (iTNSS). Over 4 weeks of treatment, FFNS significantly improved rTNSS, iTNSS, and the reflective scores for each individual symptom compared with placebo. The least squares (LS) mean treatment difference over weeks 1-4 between FFNS and placebo for rTNSS was -0.93, ranging from -0.20 to -0.28 for the individual nasal symptoms (p < 0.001 for all versus placebo). For the iTNSS, the LS mean treatment difference between FFNS and placebo over weeks 1-4 was -0.95 (95% CI,-1.24, -0.66; p < 0.001). FFNS at 110 micrograms q.d. effectively relieved all nasal symptoms of PAR including nasal congestion over a 24-hour period.

Novel study design to assess the utility of the copd assessment test in a primary care setting.

The quality of a consultation provided by a physician can have a profound impact on the quality of care and patient engagement in treatment decisions. When the COPD Assessment Test (CAT) was developed, one of its aims was to aid the communication between physician and patient about the impact of COPD. We developed a novel study design to assess this in a primary care consultation. Primary care physicians across five countries in Europe conducted videoed consultations with six standardised COPD patients (played by trained actors) which had patient-specific issues that the physician needed to identify through questioning. Half the physicians saw the patients with the completed CAT, and half without. Independent assessors scored the physicians on their ability to identify and address the patient-specific issues, review standard COPD aspects, their understanding of the case and their overall performance. This novel study design presented many challenges which needed to be addressed to achieve an acceptable level of robustness to assess the utility of the CAT. This paper discusses these challenges and the measures adopted to eliminate or minimise their impact on the study results.

Utility of COPD Assessment Test (CAT) in primary care consultations: a randomised controlled trial.

BACKGROUND: One of the aims of the COPD Assessment Test (CAT) is to aid communication between the physician and patient about the burden of chronic obstructive pulmonary disease (COPD) on the patient's life. AIMS: To investigate the impact of the CAT on the quality of primary care consultations in COPD patients. METHODS: Primary care physicians across Europe conducted six consultations with standardised COPD patients (played by trained actors). Physicians were randomised to see the patient with the completed CAT (CAT+ arm) or without (no CAT arm) during the consultation. These were videoed and independent assessors scored the physicians on their ability to identify and address patient-specific issues such as depression (sub-score A); review standard COPD issues such as breathlessness (sub-score B); their understanding of the case (understanding score); and their overall performance. The primary endpoint was the global score (sub-scores A+B; scale range 0-40). RESULTS: A total of 165 physicians enrolled in the study and carried out six consultations each; 882 consultations were deemed suitable for analysis. No difference was seen between the arms in the global score (no CAT arm 20.3; CAT+ arm 20.7; 95% CI -1.0 to 1.8; p=0.606) or on sub-score A (p=0.255). A statistically significant difference, though of limited clinical relevance, was observed in mean sub-score B (no CAT arm 8.8; CAT+ arm 9.6; 95% CI 0.0 to 1.6; p=0.045). There was no difference in understanding score (p=0.824) or overall performance (p=0.655). CONCLUSIONS: The CAT is a disease-specific instrument that aids physician assessment of COPD. It does not appear to improve detection of non-COPD symptoms and co-morbidities.

Comparisons of health status scores with MRC grades in COPD: implications for the GOLD 2011 classification.

The 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD) strategy document recommends assessment of chronic obstructive pulmonary disease (COPD) using symptoms and future exacerbation risk, employing two score cut-points: COPD Assessment Test (CAT) score ≥ 10 or modified Medical Research Council dyspnoea scale (mMRC) grade ≥ 2. To explore the equivalence of these two symptom cut-points, the relationship between the CAT and the mMRC and St George's Respiratory Questionnaire (SGRQ), the Short-form Health Survey and the Functional Assessment of Chronic Illness Therapy Fatigue scores were retrospectively analysed using a primary care dataset. Data from 1817 patients (mean ± SD forced expiratory volume in 1 s 1.6 ± 0.6 L) showed a significant association between mMRC grades and all health status scores (ANOVA p<0.0001). mMRC grade 1 was associated with significant levels of health status impairment (SGRQ 39.4 ± 15.5 and CAT 15.7 ± 7.0); even patients with mMRC grade 0 had modestly elevated scores (SGRQ 28.5 ± 15.1 and CAT 11.7 ± 6.8). An mMRC grading ≥ 2 categorised 57.2% patients with low symptom (groups A and C) versus 17.2% with the CAT. Using the mMRC cut-point (≥ 1) resulted in similar GOLD group categorisations as the CAT (18.9%). The mMRC showed a clear relationship with health status scores; even low mMRC grades were associated with health status impairment. Cut-points of mMRC grade ≥ 1 and CAT score ≥ 10 were approximately equivalent in determining low-symptom patients. The GOLD assessment framework may require refinement.

Primary care physician perceptions on the diagnosis and management of chronic obstructive pulmonary disease in diverse regions of the world.

Chronic obstructive pulmonary disease (COPD) is a multicomponent disorder that leads to substantial disability, impaired quality of life, and increased mortality. Although the majority of COPD patients are first diagnosed and treated in primary care practices, there is comparatively little information on the management of COPD patients in primary care. A web-based pilot survey was conducted to evaluate the primary care physician's, or general practitioner's (GP's), knowledge, understanding, and management of COPD in twelve territories across the Asia-Pacific region, Africa, eastern Europe, and Latin America, using a 10-minute questionnaire comprising 20 questions and translated into the native language of each participating territory. The questionnaire was administered to a total of 600 GPs (50 from each territory) involved in the management of COPD patients and all data were collated and analyzed by an independent health care research consultant. This survey demonstrated that the GPs' understanding of COPD was variable across the territories, with large numbers of GPs having very limited knowledge of COPD and its management. A consistent finding across all territories was the underutilization of spirometry (median 26%; range 10%-48%) and reliance on X-rays (median 14%; range 5%-22%) for COPD diagnosis, whereas overuse of blood tests (unspecified) was particularly high in Russia and South Africa. Similarly, there was considerable underrecognition of the importance of exacerbation history as an important factor of COPD and its initial management in most territories (median 4%; range 0%-22%). Management of COPD was well below guideline-recommended levels in most of the regions investigated. The findings of this survey suggest there is a need for more ongoing education and information, specifically directed towards GPs outside of Europe and North America, and that global COPD guidelines appear to have limited reach and application in most of the areas studied.