COPD: Journal of Chronic Obstructive Pulmonary Disease 

About: COPD: Journal of Chronic Obstructive Pulmonary Disease is an academic journal published by Informa. The journal publishes majorly in the area(s): COPD & Exacerbation. It has an ISSN identifier of 1541-2563. Over the lifetime, 1347 publications have been published receiving 35515 citations. The journal is also known as: COPD.

Genetic Epidemiology of COPD (COPDGene) Study Design

Abstract: Background: COPDGene is a multicenter observational study designed to identify genetic factors associated with COPD. It will also characterize chest CT phenotypes in COPD subjects, including assessment of emphysema, gas trapping, and airway wall thickening. Finally, subtypes of COPD based on these phenotypes will be used in a comprehensive genome-wide study to identify COPD susceptibility genes. Methods/Results: COPDGene will enroll 10,000 smokers with and without COPD across the GOLD stages. Both Non-Hispanic white and African-American subjects are included in the cohort. Inspiratory and expiratory chest CT scans will be obtained on all participants. In addition to the cross-sectional enrollment process, these subjects will be followed regularly for longitudinal studies. A genome-wide association study (GWAS) will be done on an initial group of 4000 subjects to identify genetic variants associated with case-control status and several quantitative phenotypes related to COPD. The initial findings w...

St. George's Respiratory Questionnaire: MCID.

Abstract: The SGRQ is a disease-specific measure of health status for use in COPD. A number of methods have been used for estimating its minimum clinically important difference (MCID). These include both expert and patient preference-based estimates. Anchor-based methods have also been used. The calculated MCID from those studies was consistently around 4 units, regardless of assessment method. By contrast, the MCID calculated using distribution-based methods varied across studies and permitted no consistent estimate. All measurements of clinical significance contain sample and measurement error. They also require value judgements, if not about the calculation of the MCID itself then about the anchors used to estimate it. Under these circumstances, greater weight should be placed upon the overall body of evidence for an MCID, rather than one single method. For that reason, estimates of MCID should be used as indicative values. Methods of analysing clinical trial results should reflect this, and use appropriate statistical tests for comparison with the MCID. Treatments for COPD that produced an improvement in SGRQ of the order of 4 units in clinical trials have subsequently found wide acceptance once in clinical practice, so it seems reasonable to expect any new treatment proposed for COPD to produce an advantage over placebo that is not significantly inferior to a 4-unit difference.

Identifying individuals with physcian diagnosed COPD in health administrative databases.

Abstract: Chronic Obstructive Pulmonary Disease (COPD) is a common chronic respiratory disease responsible for significant morbidity and mortality. Population-based health administrative databases provide a powerful and unbiased way of studying COPD in the population, however, their ability to accurately identify patients with this disease must first be confirmed. The objective was to validate population-based health administrative definitions of COPD. Previously abstracted medical records of adults over the age of 35 randomly selected from primary care practices in Ontario, Canada were reviewed by an expert panel to establish if an individual did or did not have a diagnosis of COPD. These reference designations were then linked to each individual's respective health administrative database record and compared with predefine health administrative data definitions of COPD. Concepts of diagnostic test evaluation were used to calculate and compare their test characteristics. The most sensitive health administrative definition of COPD was 1 or more ambulatory claims and/or 1 or more hospitalizations for COPD that yielded a sensitivity of 85.0% (95% confidence interval 77.0 to 91.0) and a specificity of 78.4% (95% confidence interval 73.6 to 82.7). As number of ambulatory claims in the definition increased, sensitivity decreased and specificity increased. Individuals with COPD can be accurately identified in health administrative data, and therefore it may be used to create an unbiased population cohort for surveillance and research. This offers a powerful means of generating evidence to inform strategies that optimize the prevention and management of COPD.

Minimal Clinically Important Differences in COPD Lung Function

Abstract: The FEV1 is widely used by physicians in the diagnosis, staging, treatment, monitoring, and establishing prognosis for patients with COPD. The MCID is the smallest difference which patients perceive as beneficial and which would mandate a change in patient management. A precise MCID for FEV1 has not been established. In attempt to establish a MCID for predose or trough FEV1, several limitations need to be addressed. There are issues such as reproducibility, repeatability, acceptability, variability, placebo effect, and equipment effects. Patient factors, such as baseline level of FEV1, albuterol reversibility, diurnal variation, influence the results. Nonetheless, using anchoring techniques, a change in pre dose FEV1 of about 100 mL can be perceived by patients, correlates with fewer relapses following exacerbations and is in the range usually achieved with bronchodilators approved for COPD. In the future, consistent reporting of spirometric variables, such as a predose FEV1 and other outcomes, can be incorporated into a more quantitative effort to establish the MCID. Also distributional/statistical methods may be useful in determining the MCID FEV1.