1,720,986 research outputs found
Definition, epidemiology and natural history of COPD
No full textChronic obstructive pulmonary disease (COPD) is the fifth cause of morbidity and
mortality in the developed world and represents a substantial economic and social burden.
Patients experience a progressive deterioration up to end-stage COPD, characterised by very
severe airflow limitation, severely limited and declining performance status with chronic
respiratory failure, advanced age, multiple comorbidities and severe systemic manifestations/
complications.
COPD is frequently underdiagnosed and under-treated. Today, COPD develops earlier in life
and is less gender specific. Tobacco smoking is the major risk factor for COPD, followed by
occupation and air pollution. Severe deficiency for a1-antitrypsin is rare; several phenotypes are
being associated with elevated risk for COPD in the presence of risk factor exposure. Any patient
presenting with cough, sputum production or dyspnoea should be assessed by standardised
spirometry. Continued exposure to noxious agents promotes a more rapid decline in lung function
and increases the risk for repeated exacerbations, eventually leading to end-stage disease.
Without major efforts in prevention, there will be an increasing proportion of end-stage patients
who can live longer through long-term oxygen therapy and assisted ventilation, but with elevated
suffering and huge costs. Smoking prevention and smoking cessation are the most important
epidemiological measurements to counteract chronic obstructive pulmonary disease epidemic
Single breath nitrogen test as predictor of lung function decline and COPD over an 8-year follow-up
No full textHigh cytomegalovirus serology and subsequent copd-related mortality. a longitudinal study
Full text linkBackground: Positive serology for cytomegalovirus (CMV) has been associated with all-cause mortality risk but its role in COPD mortality is unknown. The objective of the present study was to assess the relationship between CMV serology and COPD mortality. Methods: We analysed data from 806 participants in the Tucson Epidemiological Study of Airway Obstructive Disease who, at enrolment, were aged 28–70 years and had completed lung function tests. We tested CMV serology in sera from enrolment and defined “high CMV serology” as being in the highest tertile. Vital status, date and cause of death were assessed through death certificates and/or linkage with the National Death Index up to January 2017. The association of CMV serology with all-cause and cause-specific mortality risk was tested in Cox models adjusted for age, sex, level of education, body mass index, smoking status and pack-years. Results: High CMV serology was marginally associated with all-cause mortality (p=0.071) but the effect was inversely dependent on age, with the association being much stronger among participants <55 years than among participants ⩾55 years at enrolment (p-value for CMV-by-age interaction <0.001). Compared with low CMV serology, high CMV serology was associated with mortality from COPD among all subjects (adjusted hazard ratio (HR) 2.38, 95% CI 1.11–5.08; p=0.025) and particularly in subjects <55 years old at enrolment (HR 5.40, 95% CI 1.73–16.9; p=0.004). Consistent with these results, high CMV serology also predicted mortality risk among subjects who already had airflow limitation at enrolment (HR 2.10, 95% CI 1.20–3.68; p=0.009). Conclusions: We report a strong relationship between CMV serology and the risk of dying from COPD, and thus identify a novel risk factor for COPD mortality
L’iper-reattività bronchiale (BHR) è associata con la residenza in area urbana in campioni di popolazione gnerale
No full textLongitudinal assessment of risk factors exposure and development of allergic respiratory symptoms/diseases
No full textAssociation between single breath nitrogen test in indexes and incident COPD in an 8-year epidemiological study
No full textThe association between single breath nitrogen test (SBN2T) indexes and lung function decline, to our knowledge, has not been investigated in a longitudinal epidemiological study.
Aim of this study was to assess whether SBN2T indexes are associated with lung function decline in a population-based longitudinal 8-year study.
908 adults aged 20+ years (56% males) underwent to SBN2T at baseline and spirometry testing at both baseline and follow-up. FEV1 decline (dFEV1) was computed as difference between follow-up and baseline value, divided by duration between the two. Linear multiple regressions were used to assess associations between closing volume (CV), CV/slow vital capacity (CV/VC) and N2 slope, and dFEV1, while adjusting for sex, age, and baseline FEV1. Differences based on reported baseline smoking status (never, current, ex) were also tested.
There were no significant associations between CV or CV/VC and dFEV1. However, N2 slope had a statistically significant linear association (p < 0.001) with dFEV1; for every unit increase in N2 slope, the expected dFEV1 decreased by 7.79 mL/yr. Among subjects aged > 35, current smoking was associated with more rapid rates of dFEV1 decline (-6.61 mL/yr; p = 0.027) compared to never smokers.
N2 slope is associated with an increased lung function decline over 8-year follow-up, indicating that tests exploring small airways may have an important role in predicting subsequent respiratory diseases
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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