Reference values for six-minute walk distance and six-minute walk work in Caucasian adults.

RATIONALE: The six-minute walk test (6MWT) is a practical and simple field-based test to assess physical capacity. Several reference equations for six-minute walking distance (6MWD, m) exist, but have a number of limitations that decrease their clinical utility. In addition, no reference equations exist for the 6MWT-derived outcome six-minute walk work (6MWORK, kg.m). OBJECTIVES: To establish new reference equations for 6MWD and 6MWORK on a 20 m course using data from the population-based Canadian Cohort Obstructive Lung Disease study. METHODS AND MEASUREMENTS: A total of 335 participants without obstructive or restrictive pulmonary function, with normal self-reported health status, normal exercise capacity, and <30 pack years cigarette smoking history were selected to create a representative sample of Canadian adults aged ≥40 years. All participants performed two 6MWTs. Reference equations were derived using multiple regression analyses. MAIN RESULTS: On average, 6MWD and 6MWORK were 541±98 m and 41.3 ± 11.2 kg.m, respectively. All outcomes were significantly greater in males than females. Sex-specific reference equations were derived from the results of 6MWD and 6MWORK with an explained variance of 24 to 35%. CONCLUSIONS: This study established reference equations for 6MWD and 6MWORK on a 20 m course in Caucasian males and females aged ≥40 years with normal pulmonary function, self-reported health status and exercise capacity. These newly derived reference equations add value to the assessment of functional capacity in clinical practice.

[Therapeutic patient education in respiratory rehabilitation]. / Éducation thérapeutique du patient au cours de la réadaptation respiratoire.

INTRODUCTION: Therapeutic patient education (TPE) is an essential component of pulmonary readaptation in chronic respiratory diseases. Numerous and varied patient education projects offer heterogeneous contents and methods, which render them difficult to analyze and to compare. The objective of this review was to provide perspective on the main principles of patient education, using a non-exhaustive approach. STATE OF KNOWLEDGE: This review is focused on patient education using a patient-centered approach, physician-patient partnership and self-management, which are presented at once pragmatically and conceptually. One of the main objectives of TPE is the acquisition of self-management skills by patients with a chronic disease, which will be considered from a clinical standpoint. Lastly, TPE will be assessed in the overall framework of patient-centered pulmonary readaptation. PERSPECTIVES: TPE needs to be structured in view of assessing its effects. It is consequently essential for caregivers to receive continuous training so as to more clearly understand the methods employed, the objective being to build evaluable contents contributing to performance of multicentric trials. CONCLUSION: Current literature on TPE emphasizes the extent to which the patient remains the central actor in his or her care pathway. If patients are called upon to modify their behaviors, it is equally necessary that caregivers proceed likewise, adopting postures favoring the acquisition and appropriation by the patient of skills that shall be required as he or she learns to live with chronic disease.

eV-Scale Sterile Neutrino Search Using Eight Years of Atmospheric Muon Neutrino Data from the IceCube Neutrino Observatory.

The results of a 3+1 sterile neutrino search using eight years of data from the IceCube Neutrino Observatory are presented. A total of 305 735 muon neutrino events are analyzed in reconstructed energy-zenith space to test for signatures of a matter-enhanced oscillation that would occur given a sterile neutrino state with a mass-squared differences between 0.01 and 100 eV^{2}. The best-fit point is found to be at sin^{2}(2θ_{24})=0.10 and Δm_{41}^{2}=4.5 eV^{2}, which is consistent with the no sterile neutrino hypothesis with a p value of 8.0%.

Characteristics of the Diffuse Astrophysical Electron and Tau Neutrino Flux with Six Years of IceCube High Energy Cascade Data.

We report on the first measurement of the astrophysical neutrino flux using particle showers (cascades) in IceCube data from 2010-2015. Assuming standard oscillations, the astrophysical neutrinos in this dedicated cascade sample are dominated (∼90%) by electron and tau flavors. The flux, observed in the sensitive energy range from 16 TeV to 2.6 PeV, is consistent with a single power-law model as expected from Fermi-type acceleration of high energy particles at astrophysical sources. We find the flux spectral index to be γ=2.53±0.07 and a flux normalization for each neutrino flavor of ϕ_{astro}=1.66_{-0.27}^{+0.25} at E_{0}=100 TeV, in agreement with IceCube's complementary muon neutrino results and with all-neutrino flavor fit results. In the measured energy range we reject spectral indices γ≤2.28 at ≥3σ significance level. Because of high neutrino energy resolution and low atmospheric neutrino backgrounds, this analysis provides the most detailed characterization of the neutrino flux at energies below ∼100 TeV compared to previous IceCube results. Results from fits assuming more complex neutrino flux models suggest a flux softening at high energies and a flux hardening at low energies (p value ≥0.06). The sizable and smooth flux measured below ∼100 TeV remains a puzzle. In order to not violate the isotropic diffuse gamma-ray background as measured by the Fermi Large Area Telescope, it suggests the existence of astrophysical neutrino sources characterized by dense environments which are opaque to gamma rays.

Time-Integrated Neutrino Source Searches with 10 Years of IceCube Data.

This Letter presents the results from pointlike neutrino source searches using ten years of IceCube data collected between April 6, 2008 and July 10, 2018. We evaluate the significance of an astrophysical signal from a pointlike source looking for an excess of clustered neutrino events with energies typically above ∼1 TeV among the background of atmospheric muons and neutrinos. We perform a full-sky scan, a search within a selected source catalog, a catalog population study, and three stacked Galactic catalog searches. The most significant point in the northern hemisphere from scanning the sky is coincident with the Seyfert II galaxy NGC 1068, which was included in the source catalog search. The excess at the coordinates of NGC 1068 is inconsistent with background expectations at the level of 2.9σ after accounting for statistical trials from the entire catalog. The combination of this result along with excesses observed at the coordinates of three other sources, including TXS 0506+056, suggests that, collectively, correlations with sources in the northern catalog are inconsistent with background at 3.3σ significance. The southern catalog is consistent with background. These results, all based on searches for a cumulative neutrino signal integrated over the 10 years of available data, motivate further study of these and similar sources, including time-dependent analyses, multimessenger correlations, and the possibility of stronger evidence with coming upgrades to the detector.

Constraints on Minute-Scale Transient Astrophysical Neutrino Sources.

High-energy neutrino emission has been predicted for several short-lived astrophysical transients including gamma-ray bursts (GRBs), core-collapse supernovae with choked jets, and neutron star mergers. IceCube's optical and x-ray follow-up program searches for such transient sources by looking for two or more muon neutrino candidates in directional coincidence and arriving within 100 s. The measured rate of neutrino alerts is consistent with the expected rate of chance coincidences of atmospheric background events and no likely electromagnetic counterparts have been identified in Swift follow-up observations. Here, we calculate generic bounds on the neutrino flux of short-lived transient sources. Assuming an E^{-2.5} neutrino spectrum, we find that the neutrino flux of rare sources, like long gamma-ray bursts, is constrained to <5% of the detected astrophysical flux and the energy released in neutrinos (100 GeV to 10 PeV) by a median bright GRB-like source is <10^{52.5} erg. For a harder E^{-2.13} neutrino spectrum up to 30% of the flux could be produced by GRBs and the allowed median source energy is <10^{52} erg. A hypothetical population of transient sources has to be more common than 10^{-5} Mpc^{-3} yr^{-1} (5×10^{-8} Mpc^{-3} yr^{-1} for the E^{-2.13} spectrum) to account for the complete astrophysical neutrino flux.

Prevalence and predictors of airflow obstruction in an HIV tertiary care clinic in Montreal, Canada: a cross-sectional study.

OBJECTIVES: The reported prevalence of chronic obstructive pulmonary disease (COPD) in people living with HIV (PLWHIV) varies widely. Our objective was to estimate the prevalence of airflow obstruction and COPD in unselected PLWHIV and identify characteristics that increase the risk of nonreversible airflow obstruction in order to guide case finding strategies for COPD. METHODS: All adults attending the Chronic Viral Illness Service were invited to participate in the study, regardless of smoking status or history of known COPD/asthma. Individuals underwent spirometric testing both before and after use of a salbutamol bronchodilator. Airflow obstruction was defined as forced expiratory volume in 1 s (FEV1 )/forced vital capacity (FVC) < 0.7 post-bronchodilation, whereas COPD was defined as FEV1 /FVC < 0.7 post-bronchodilation and Medical Research Council (MRC) score > 2. Multivariate logistic regression was used to evaluate risk factors associated with airflow obstruction, reported as adjusted odds ratios (aORs). RESULTS: Five hundred and three participants successfully completed spirometry testing. The median (Q1; Q3) age was 52 (44; 58) years. The median (Q1; Q3) CD4 count was 598 (438; 784) cells/µL and the median (Q1; Q3) nadir CD4 count was 224 (121; 351) cells/µL. There were 119 (24%) current smokers and 145 (29%) former smokers. Among those screened, 54 (11%) had airflow obstruction whereas three (1%) of the participants had COPD. Factors that were associated with airflow obstruction included a history of smoking [aOR 2.2; 95% confidence interval (CI) 1.1; 4.7], older age (aOR 1.6; 95% CI 1.2; 2.2), and lower CD4 count (aOR 0.8; 95% CI 0.7; 1.0). CONCLUSIONS: Airflow obstruction was relatively uncommon. Our findings suggest that PLWHIV who are ≥50 years old, smokers and those with nadir CD4 counts ≤ 200 cells/µL could be targeted to undergo spirometry to diagnose chronic airflow obstruction.

Measurement of Atmospheric Neutrino Oscillations at 6-56 GeV with IceCube DeepCore.

We present a measurement of the atmospheric neutrino oscillation parameters using three years of data from the IceCube Neutrino Observatory. The DeepCore infill array in the center of IceCube enables the detection and reconstruction of neutrinos produced by the interaction of cosmic rays in Earth's atmosphere at energies as low as ∼5 GeV. That energy threshold permits measurements of muon neutrino disappearance, over a range of baselines up to the diameter of the Earth, probing the same range of L/E_{ν} as long-baseline experiments but with substantially higher-energy neutrinos. This analysis uses neutrinos from the full sky with reconstructed energies from 5.6 to 56 GeV. We measure Δm_{32}^{2}=2.31_{-0.13}^{+0.11}×10^{-3} eV^{2} and sin^{2}θ_{23}=0.51_{-0.09}^{+0.07}, assuming normal neutrino mass ordering. These results are consistent with, and of similar precision to, those from accelerator- and reactor-based experiments.

Search for neutrinos from decaying dark matter with IceCube: IceCube Collaboration.

With the observation of high-energy astrophysical neutrinos by the IceCube Neutrino Observatory, interest has risen in models of PeV-mass decaying dark matter particles to explain the observed flux. We present two dedicated experimental analyses to test this hypothesis. One analysis uses 6 years of IceCube data focusing on muon neutrino 'track' events from the Northern Hemisphere, while the second analysis uses 2 years of 'cascade' events from the full sky. Known background components and the hypothetical flux from unstable dark matter are fitted to the experimental data. Since no significant excess is observed in either analysis, lower limits on the lifetime of dark matter particles are derived: we obtain the strongest constraint to date, excluding lifetimes shorter than 10 28 s at 90% CL for dark matter masses above 10 TeV .

Telehealth pulmonary rehabilitation: A review of the literature and an example of a nationwide initiative to improve the accessibility of pulmonary rehabilitation.

Several different applications of telehealth technologies have been used in the care of respiratory patients, including telemonitoring, teleconsultations, tele-education, and telehealth-pulmonary rehabilitation (PR). Telehealth technology provides an opportunity to assist in the management of chronic respiratory diseases and improve access to PR programs. While there is inconclusive evidence as to the effectiveness of telemonitoring to reduce healthcare utilization and detection of exacerbations, teleconsultations have been shown to be an effective means to assess patients' disease prior to the initiation of PR, and telehealth PR has been shown to be as effective as institution-based PR at improving functional exercise capacity and health-related quality of life. To improve PR access across Canada and ensure a high standard of program quality, a team of clinicians and researchers has developed and begun to implement a national standardized PR program that can be delivered across different settings of practice, including remote satellite sites via telehealth PR. The program has adapted the "Living Well with COPD" self-management program and includes standardized reference guides and resources for patients and practitioners. A progressive and iterative process will evaluate the success of program implementation and outcomes. This initiative will address nationwide accessibility challenges and provide PR content as well as evaluations that are in accordance with clinical standards and established self-management practices.

Evaluating the risk of pneumonia with inhaled corticosteroids in COPD: Retrospective database studies have their limitations SA.

An increased risk of non-fatal pneumonia has been documented in COPD patients treated with inhaled corticosteroids (ICS) in randomized clinical trials. Retrospective database analyses have been conducted to evaluate this signal in larger populations treated in the community. To understand how methodological choices may influence results in observational studies, we compared two recent Canadian studies which used health administrative databases from Quebec and Ontario and came to opposite conclusions on the risk of pneumonia in ICS treated COPD patients. Explanations for why the results of these studies diverged are explored. The Suissa analysis used RAMQ data from Quebec and showed an increased relative risk of serious pneumonia for current users of ICS compared to non users, RR = 1.69 (95% confidence interval, 1.63-1.75). The Gershon analysis used ODB data and showed no difference for pneumonia hospitalisation, RR = 1.01 (0.93-1.08). Reasons for differences in study findings include lack of validated definitions of COPD, poor selection of relevant exposure groups, channeling and confounding biases, and failure to perform on-treatment analyses for safety. CONCLUSION: Our study identifies methodological features that need consideration to increase robustness and minimize threats to internal validity of retrospective health administrative database studies.

Comprehensive Self-Management Strategies.

In this article, we provide a review of the literature on self-management interventions and we are giving some thought to how, when, and by whom they should be offered to patients. The present literature based on randomized clinical trials has demonstrated benefits (reduced hospital admissions and improved health status) for chronic obstructive pulmonary disease (COPD) patients undergoing self-management interventions, although there are still problems with the heterogeneity among interventions, study populations, follow-up time, and outcome measures that make generalization difficult in real life. Key to the success, self-management intervention has to target behavior change. Proper self-management support is a basic prerequisite, for example, techniques and skills used by health care providers "case manager" to instrument patients with the knowledge, confidence, and skills required to effectively self-manage their disease. To improve health behaviors and engagement in self-management, self-management interventions need to target enhancing intrinsic motivation to change. This will best be done using client-centered communication (motivational communication) that encourages patients to express what intrinsically motivates them (e.g., consistent with their values or life goals) to adopt certain health behavior, with the goal of helping them overcome their ambivalence about change. Finally, if we want to be able to design and implement self-management interventions that are integrated, coherent, and have a strong likelihood of success, we need to take a more careful look and give more attention at the case manager, the patient (patient evaluation), and the quality assurance.

Characteristics of COPD in never-smokers and ever-smokers in the general population: results from the CanCOLD study.

BACKGROUND: There is limited data on the risk factors and phenotypical characteristics associated with spirometrically confirmed COPD in never-smokers in the general population. AIMS: To compare the characteristics associated with COPD by gender and by severity of airway obstruction in never-smokers and in ever-smokers. METHOD: We analysed the data from 5176 adults aged 40 years and older who participated in the initial cross-sectional phase of the population-based, prospective, multisite Canadian Cohort of Obstructive Lung Disease study. Never-smokers were defined as those with a lifetime exposure of <1/20 pack year. Logistic regressions were constructed to evaluate associations for 'mild' and 'moderate-severe' COPD defined by FEV1/FVC <5th centile (lower limits of normal). Analyses were performed using SAS V.9.1 (SAS Institute, Cary, North Carolina, USA). RESULTS: The prevalence of COPD (FEV1/FVC

Exacerbation-like respiratory symptoms in individuals without chronic obstructive pulmonary disease: results from a population-based study.

RATIONALE: Exacerbations of COPD are defined clinically by worsening of chronic respiratory symptoms. Chronic respiratory symptoms are common in the general population. There are no data on the frequency of exacerbation-like events in individuals without spirometric evidence of COPD. AIMS: To determine the occurrence of 'exacerbation-like' events in individuals without airflow limitation, their associated risk factors, healthcare utilisation and social impacts. METHOD: We analysed the cross-sectional data from 5176 people aged 40 years and older who participated in a multisite, population-based study on lung health. The study cohort was stratified into spirometrically defined COPD (post-bronchodilator FEV1/FVC < 0.7) and non-COPD (post bronchodilator FEV1/FVC ≥ 0.7 and without self-reported doctor diagnosis of airway diseases) subgroups and then into those with and without respiratory 'exacerbation-like' events in the past year. RESULTS: Individuals without COPD had half the frequency of 'exacerbation-like' events compared with those with COPD. In the non-COPD group, the independent associations with 'exacerbations' included female gender, presence of wheezing, the use of respiratory medications and self-perceived poor health. In the non-COPD group, those with exacerbations were more likely than those without exacerbations to have poorer health-related quality of life (12-item Short-Form Health Survey), miss social activities (58.5% vs 18.8%), miss work for income (41.5% vs 17.3%) and miss housework (55.6% vs 16.5%), p<0.01 to <0.0001. CONCLUSIONS: Events similar to exacerbations of COPD can occur in individuals without COPD or asthma and are associated with significant health and socioeconomic outcomes. They increase the respiratory burden in the community and may contribute to the false-positive diagnosis of asthma or COPD.

Alpha-1 antitrypsin deficiency targeted testing and augmentation therapy: a Canadian Thoracic Society clinical practice guideline.

Alpha-1 antitrypsin (A1AT) functions primarily to inhibit neutrophil elastase, and deficiency predisposes individuals to the development of chronic obstructive pulmonary disease (COPD). Severe A1AT deficiency occurs in one in 5000 to one in 5500 of the North American population. While the exact prevalence of A1AT deficiency in patients with diagnosed COPD is not known, results from small studies provide estimates of 1% to 5%. The present document updates a previous Canadian Thoracic Society position statement from 2001, and was initiated because of lack of consensus and understanding of appropriate patients suitable for targeted testing for A1AT deficiency, and for the use of A1AT augmentation therapy. Using revised guideline development methodology, the present clinical practice guideline document systematically reviews the published literature and provides an evidence-based update. The evidence supports the practice that targeted testing for A1AT deficiency be considered in individuals with COPD diagnosed before 65 years of age or with a smoking history of <20 pack years. The evidence also supports consideration of A1AT augmentation therapy in nonsmoking or exsmoking patients with COPD (forced expiratory volume in 1 s of 25% to 80% predicted) attributable to emphysema and documented A1AT deficiency (level ≤11 µmol/L) who are receiving optimal pharmacological and nonpharmacological therapies (including comprehensive case management and pulmonary rehabilitation) because of benefits in computed tomography scan lung density and mortality.

Trajectories of endurance activity following pulmonary rehabilitation in COPD patients.

Maintenance of physical activity following pulmonary rehabilitation remains a challenge for patients with chronic obstructive pulmonary disease (COPD). The objectives of this study were to identify patterns of endurance activity after completion of pulmonary rehabilitation and to characterise people who succeed and those who have difficulty maintaining endurance activity. In a longitudinal study embedded within a randomised clinical trial, 206 individuals with COPD underwent a 3-month pulmonary rehabilitation programme. Weekly duration of endurance activity was assessed at 4, 6, 8 and 12 months after the start of rehabilitation. Trajectory modelling was used to determine the most common patterns of activity during the post-rehabilitation phase from 4-12 months. Three distinct patterns were identified, two of which indicated difficulty in maintaining endurance activity: 61 individuals reported a high activity level at 4 months (2.7 h·week(-1)) and stayed high; 114 individuals started at a low activity level (mean 1.0 h·week(-1)) and stayed low; and 31 individuals started high (3.0 h·week(-1)) and declined. The low activity group was characterised by more severe disease and greater respiratory impairment. The high and declined group had less severe disease and respiratory impairment, but reported greater barriers to exercise. Pulmonary rehabilitation should include interventions aimed at minimising barriers, in order to induce long-term behaviour change.

Canadian prediction equations of spirometric lung function for Caucasian adults 20 to 90 years of age: results from the Canadian Obstructive Lung Disease (COLD) study and the Lung Health Canadian Environment (LHCE) study.

BACKGROUND: Currently, no reference or normative values for spirometry based on a randomly selected Canadian population exist. OBJECTIVE: The aim of the present analysis was to construct spirometric reference values for Canadian adults 20 to 90 years of age by combining data collected from healthy lifelong nonsmokers in two population-based studies. METHOD: Both studies similarly used random population sampling, conducted using validated epidemiological protocols in the Canadian Obstructive Lung Disease study, and the Lung Health Canadian Environment study. Spirometric lung function data were available from 3042 subjects in the COLD study, which was completed in 2009, and from 2571 subjects in the LHCE study completed in 1995. A total of 844 subjects 40 to 90 years of age, and 812 subjects 20 to 44 years of age, were identified as healthy, asymptomatic, lifelong nonsmokers, and provided normative reference values for spirometry. Multiple regression models were constructed separately for Caucasian men and women for the following spirometric parameters: forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC) and FEV(1)/FVC ratio, with covariates of height, sex and age. Comparison with published regression equations showed that the best agreement was obtained from data derived from random populations. RESULTS: The best-fitting regression models for healthy, never-smoking, asymptomatic European-Canadian men and women 20 to 90 years of age were constructed. When age- and height-corrected FEV(1), FVC and FEV(1)/FVC ratio were compared with other spirometry reference studies, mean values were similar, with the closest being derived from population-based studies. CONCLUSION: These spirometry reference equations, derived from randomly selected population-based cohorts with stringently monitored lung function measurements, provide data currently lacking in Canada.

Can age and sex explain the variation in COPD rates across large urban cities? A population study in Canada.

OBJECTIVE: To measure the prevalence of chronic obstructive pulmonary disease (COPD) and determine the effect of age and sex on the variation in prevalence across major cities within the same country and health care system. METHOD: We used the Burden of Obstructive Lung Disease (BOLD) methodology to estimate the prevalence of COPD in adults aged ≥ 40 years in different Canadian cities. The study used interviewer-administered questionnaires on respiratory, smoking and occupational history, medication use and comorbidities. Post-bronchodilator spirometry was used to classify subjects. We determined the prevalence and severity of COPD with and without adjustments for age and sex distribution across different cities. RESULTS: The study population was 3042. Overall, 16.7% (95%CI 14.8-18.7) of study subjects met the criteria for Global Initiative for Chronic Obstructive Lung Disease (GOLD) severity Stage 1 or higher. The prevalence according to the criteria for the lower limits of normal of the ratio forced expiratory volume in 1 second/forced vital capacity was 11.6% (95%CI 9.9-13.3). COPD prevalence varied by severity across site (P = 0.0025). After age-sex adjustment, the variation disappeared (P> 0.16). CONCLUSION: Age and sex differences account for most of the heterogeneity in COPD estimates across large cities within the same country. Adjustments for age and sex are essential in comparing COPD rates across the country.