Development and first validation of the COPD Assessment Test
TL;DR: The aim of the present study was to develop a short validated patient-completed questionnaire, the COPD Assessment Test (CAT), assessing the impact of COPD on health status, which has good measurement properties, is sensitive to differences in state and should provide a valid, reliable and standardised measure of COPd health status with worldwide relevance.
Abstract: There is need for a validated short, simple instrument to quantify chronic obstructive pulmonary disease (COPD) impact in routine practice to aid health status assessment and communication between patient and physician. Current health-related quality of life questionnaires provide valid assessment of COPD, but are complex, which limits routine use. The aim of the present study was to develop a short validated patient-completed questionnaire, the COPD Assessment Test (CAT), assessing the impact of COPD on health status. 21 candidate items identified through qualitative research with COPD patients were used in three prospective international studies (Europe and the USA, n51,503). Psychometric and Rasch analyses identified eight items fitting a unidimensional model to form the CAT. Items were tested for differential functioning between countries. Internal consistency was excellent: Cronbach's a50.88. Test re-test in stable patients (n553) was very good (intra-class correlation coefficient 0.8). In the sample from the USA, the correlation with the COPD-specific version of the St George's Respiratory Questionnaire was r50.80. The difference between stable (n5229) and exacerbation patients (n567) was five units of the 40-point scale (12%; p,0.0001). The CAT is a short, simple questionnaire for assessing and monitoring COPD. It has good measurement properties, is sensitive to differences in state and should provide a valid, reliable and standardised measure of COPD health status with worldwide relevance.
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University of Manchester1, University of Barcelona2, St George's Hospital3, University of Marburg4, University of Texas Health Science Center at San Antonio5, Imperial College London6, University of Modena and Reggio Emilia7, University of Michigan8, Hokkaido University9, University of British Columbia10
TL;DR: It is recommended that spirometry is required for the clinical diagnosis of COPD to avoid misdiagnosis and to ensure proper evaluation of severity of airflow limitation.
Abstract: Chronic obstructive pulmonary disease (COPD) remains a major public health problem. It is the fourth leading cause of chronic morbidity and mortality in the United States, and is projected to rank fifth in 2020 in burden of disease worldwide, according to a study published by the World Bank/World Health Organization. Yet, COPD remains relatively unknown or ignored by the public as well as public health and government officials. In 1998, in an effort to bring more attention to COPD, its management, and its prevention, a committed group of scientists encouraged the U.S. National Heart, Lung, and Blood Institute and the World Health Organization to form the Global Initiative for Chronic Obstructive Lung Disease (GOLD). Among the important objectives of GOLD are to increase awareness of COPD and to help the millions of people who suffer from this disease and die prematurely of it or its complications. The first step in the GOLD program was to prepare a consensus report, Global Strategy for the Diagnosis, Management, and Prevention of COPD, published in 2001. The present, newly revised document follows the same format as the original consensus report, but has been updated to reflect the many publications on COPD that have appeared. GOLD national leaders, a network of international experts, have initiated investigations of the causes and prevalence of COPD in their countries, and developed innovative approaches for the dissemination and implementation of COPD management guidelines. We appreciate the enormous amount of work the GOLD national leaders have done on behalf of their patients with COPD. Despite the achievements in the 5 years since the GOLD report was originally published, considerable additional work is ahead of us if we are to control this major public health problem. The GOLD initiative will continue to bring COPD to the attention of governments, public health officials, health care workers, and the general public, but a concerted effort by all involved in health care will be necessary.
17,023 citations
Cites background from "Development and first validation of..."
...Questionnaires such as the CAT (87) can be performed every 2 to 3 months; trends and changes are more valuable than single measurements....
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...GOLD primarily recommends the use of the Modified British Medical Research Council (mMRC) questionnaire on breathlessness or theCOPDAssessment Test (CAT), the latter having a broader coverage of the impact of COPD on the patient’s daily life and well-being....
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...To use Figure 1, first assess symptoms and determine if the patient belongs to the left side of the box—less symptoms (as indicated by mMRC grade 0–1 or CAT, 10)—or the right side—more symptoms (as indicated by mMRC> 2 or CAT> 10)....
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...The MRC or CAT scale is recommended for assessing symptoms, with an mMRC grade greater than or equal to 2 or a CAT score greater than or equal to 10 indicating a high level of symptoms....
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...The groups can be summarized as follows: Patient group A—low risk, less symptoms GOLD 1–2 (mild or moderate airflow limitation) and 0–1 exacerbation per year andmMRC grade 0–1 or CAT score , 10 Patient group B—low risk, more symptoms GOLD 1–2 (mild or moderate airflow limitation) and 0–1 exacerbation per year and mMRC grade > 2 or CAT score > 10 Patient group C—high risk, less symptoms GOLD 3–4 (severe or very severe airflow limitation) and/or > 2 exacerbations per year and/or > 1 hospitalized exacerbation per year andmMRC grade 0–1 or CAT score, 10 Patient group D—high risk, more symptoms GOLD 3–4 (severe or very severe airflow limitation) and/or > 2 exacerbations per year / > 1 hospitalized exacerbation per year and mMRC grade > 2 or CAT score > 10 This approach, combined with an assessment of potential comorbidities, reflects the complexity of COPD better than the unidimensional analysis of airflow limitation previously used for staging the disease and forms the basis of the guide to individualized management provided in section 4....
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TL;DR: The considerable growth in the science and application of pulmonary rehabilitation since 2006 adds further support for its efficacy in a wide range of individuals with chronic respiratory disease.
Abstract: Background: Pulmonary rehabilitation is recognized as a core component of the management of individuals with chronic respiratory disease. Since the 2006 American Thoracic Society (ATS)/European Respiratory Society (ERS) Statement on Pulmonary Rehabilitation, there has been considerable growth in our knowledge of its efficacy and scope.
Purpose: The purpose of this Statement is to update the 2006 document, including a new definition of pulmonary rehabilitation and highlighting key concepts and major advances in the field.
Methods: A multidisciplinary committee of experts representing the ATS Pulmonary Rehabilitation Assembly and the ERS Scientific Group 01.02, “Rehabilitation and Chronic Care,” determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant clinical and scientific expertise. The final content of this Statement was agreed on by all members.
Results: An updated definition of pulmonary rehabilitation is proposed. New data are presented on the science and application of pulmonary rehabilitation, including its effectiveness in acutely ill individuals with chronic obstructive pulmonary disease, and in individuals with other chronic respiratory diseases. The important role of pulmonary rehabilitation in chronic disease management is highlighted. In addition, the role of health behavior change in optimizing and maintaining benefits is discussed.
Conclusions: The considerable growth in the science and application of pulmonary rehabilitation since 2006 adds further support for its efficacy in a wide range of individuals with chronic respiratory disease
Read More: http://www.atsjournals.org/doi/abs/10.1164/rccm.201309-1634ST
2,734 citations
Cites background from "Development and first validation of..."
...In the area of new outcome tools, a new quality of life instrument, the COPD Assessment Test (181), has been shown to be responsive to pulmonary rehabilitation (182–184)....
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TL;DR: There is a critical need for interdisciplinary translational research to connect Dyspnea mechanisms with clinical treatment and to validate dyspnea measures as patient-reported outcomes for clinical trials.
Abstract: Background: Dyspnea is a common, distressing symptom of cardiopulmonary and neuromuscular diseases. Since the ATS published a consensus statement on dyspnea in 1999, there has been enormous growth in knowledge about the neurophysiology of dyspnea and increasing interest in dyspnea as a patient-reported outcome.Purpose: The purpose of this document is to update the 1999 ATS Consensus Statement on dyspnea.Methods: An interdisciplinary committee of experts representing ATS assemblies on Nursing, Clinical Problems, Sleep and Respiratory Neurobiology, Pulmonary Rehabilitation, and Behavioral Science determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant expertise. The final content of this statement was agreed upon by all members.Results: Progress has been made in clarifying mechanisms underlying several qualitatively and mechanistically distinct breathing sensations. Brain imaging studies have consist...
1,331 citations
Cites background from "Development and first validation of..."
...Respiratory muscle afferents project to the cerebral cortex, and subjects report sensations localized to respiratory muscles when the work of breathing is high (49)....
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...COPD Assessment Test (CAT) (48, 49) X Impact of COPD on health status in routine outpatient / primary care practice...
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TL;DR: Although they do not meet the current criteria for COPD, symptomatic current or former smokers with preserved pulmonary function have exacerbations, activity limitation, and evidence of airway disease.
Abstract: BackgroundCurrently, the diagnosis of chronic obstructive pulmonary disease (COPD) requires a ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) of less than 0.70 as assessed by spirometry after bronchodilator use. However, many smokers who do not meet this definition have respiratory symptoms. MethodsWe conducted an observational study involving 2736 current or former smokers and controls who had never smoked and measured their respiratory symptoms using the COPD Assessment Test (CAT; scores range from 0 to 40, with higher scores indicating greater severity of symptoms). We examined whether current or former smokers who had preserved pulmonary function as assessed by spirometry (FEV1:FVC ≥0.70 and an FVC above the lower limit of the normal range after bronchodilator use) and had symptoms (CAT score, ≥10) had a higher risk of respiratory exacerbations than current or former smokers with preserved pulmonary function who were asymptomatic (CAT score, <10) and whether those w...
489 citations
Additional excerpts
...(%) 27/199 (14) 16/423 (4) 37/425 (9) 11/336 (3) 24/626 (4)...
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TL;DR: The most reliable estimate of the minimum important difference of the CAT is 2 points, which could be useful in the clinical interpretation of CAT data, particularly in response to intervention studies.
447 citations
References
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TL;DR: In this paper, a general formula (α) of which a special case is the Kuder-Richardson coefficient of equivalence is shown to be the mean of all split-half coefficients resulting from different splittings of a test, therefore an estimate of the correlation between two random samples of items from a universe of items like those in the test.
Abstract: A general formula (α) of which a special case is the Kuder-Richardson coefficient of equivalence is shown to be the mean of all split-half coefficients resulting from different splittings of a test. α is therefore an estimate of the correlation between two random samples of items from a universe of items like those in the test. α is found to be an appropriate index of equivalence and, except for very short tests, of the first-factor concentration in the test. Tests divisible into distinct subtests should be so divided before using the formula. The index
$$\bar r_{ij} $$
, derived from α, is shown to be an index of inter-item homogeneity. Comparison is made to the Guttman and Loevinger approaches. Parallel split coefficients are shown to be unnecessary for tests of common types. In designing tests, maximum interpretability of scores is obtained by increasing the first-factor concentration in any separately-scored subtest and avoiding substantial group-factor clusters within a subtest. Scalability is not a requisite.
37,235 citations
Book•
01 Jan 1980TL;DR: The most important bacterial causes of exacerbations of COPD are nontypeable Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae and Chlamydia pneumoniae.
Abstract: Chronic obstructive pulmonary disease (COPD) is a common problem in the elderly. The disease is characterised by intermittent worsening of symptoms and these episodes are called acute exacerbations. The best estimate, based on several lines of evidence, is that approximately half of all exacerbations are caused by bacteria. These lines of evidence include studies of lower respiratory tract bacteriology during exacerbations, correlation of airways’ inflammation with results of sputum cultures during exacerbations, analysis of immune responses to bacterial pathogens, and the observation in randomised, prospective, placebo-controlled trials that antibacterial therapy is of benefit. The most important bacterial causes of exacerbations of COPD are nontypeable Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae and Chlamydia pneumoniae.
3,181 citations
TL;DR: The St George's Respiratory Questionnaire is a standardized self-completed questionnaire for measuring impaired health and perceived well-being in airways disease and the background and rationale for its development are discussed together with an analysis of its performance.
2,621 citations
Journal Article•
TL;DR: In this article, the authors present national data regarding objectively determined COPD (1971-1994), COPD-associated activity and functional limitations (1980-1996), self-reported COPD prevalence, COPD physician office and hospital outpatient department visits, and COPD hospitalizations, and deaths.
Abstract: PROBLEM/CONDITION: Chronic obstructive pulmonary disease (COPD) includes chronic bronchitis and emphysema but has been defined recently as the physiologic finding of nonreversible pulmonary function impairment This surveillance summary reports trends in different measures of COPD during 1971-2000 REPORTING PERIOD COVERED: This report presents national data regarding objectively determined COPD (1971-1994); COPD-associated activity and functional limitations (1980-1996); self-reported COPD prevalence, COPD physician office and hospital outpatient department visits, COPD hospitalizations, and COPD deaths (1980-2000); and COPD emergency department visits (1992-2000) DESCRIPTION OF SYSTEMS: The Centers for Disease Control's National Center for Health Statistics conducts the National Health Interview Survey annually, which includes questions concerning COPD and activity limitations The National Center for Health Statistics collects physician office-visit data in the National Ambulatory Medical Care Survey, emergency department and hospital outpatient department data in the National Hospital Ambulatory Medical Care Survey, hospitalization data in the National Hospital Discharge Survey, and death data in the Mortality Component of the National Vital Statistics System Data regarding pulmonary function were obtained from the National Health and Nutrition Examination Surveys (NHANES) I (1971-1975) and III (1988-1994), and data regarding functional limitation were obtained from NHANES III, Phase 2 (1991-1994) RESULTS: During 2000, an estimated 10 million US adults reported physician-diagnosed COPD However, data from NHANES III estimate that approximately 24 million United States adults have evidence of impaired lung function, indicating that COPD is underdiagnosed During 2000, COPD was responsible for 8 million physician office and hospital outpatient visits, 15 million emergency department visits, 726,000 hospitalizations, and 119,000 deaths During the period analyzed, the most substantial change was the increase in the COPD death rate for women, from 201/100,000 in 1980 to 567/100,000 in 2000, compared with the more modest increase in the death rate for men, from 730/100,000 in 1980 to 826/100,000 in 2000 In 2000, for the first time, the number of women dying from COPD surpassed the number of men dying from COPD (59,936 vs 59,118) Another substantial change observed is that the proportion of the population aged < 55 years with mild or moderate COPD, on the basis of pulmonary function testing, decreased from 1971-1975 to 1988-1994, possibly indicating that the upward trends in COPD hospitalizations and mortality might not continue INTERPRETATION: COPD is a major cause of morbidity, mortality, and disability in the US Despite its ease of diagnosis, COPD remains an underdiagnosed disease, chiefly in its milder and more treatable form
1,236 citations
Journal Article•
TL;DR: The proportion of the population aged < 55 years with mild or moderate COPD, on the basis of pulmonary function testing, decreased from 1971-1975 to 1988-1994, possibly indicating that the upward trends in COPD hospitalizations and mortality might not continue.
Abstract: PROBLEM/CONDITION Chronic obstructive pulmonary disease (COPD) includes chronic bronchitis and emphysema but has been defined recently as the physiologic finding of nonreversible pulmonary function impairment. This surveillance summary reports trends in different measures of COPD during 1971-2000. REPORTING PERIOD COVERED This report presents national data regarding objectively determined COPD (1971-1994); COPD-associated activity and functional limitations (1980-1996); self-reported COPD prevalence, COPD physician office and hospital outpatient department visits, COPD hospitalizations, and COPD deaths (1980-2000); and COPD emergency department visits (1992-2000). DESCRIPTION OF SYSTEMS CDC's National Center for Health Statistics (NCHS) conducts the National Health Interview Survey annually, which includes questions concerning COPD and activity limitations. NCHS collects physician office-visit data in the National Ambulatory Medical Care Survey, emergency department and hospital outpatient department data in the National Hospital Ambulatory Medical Care Survey, hospitalization data in the National Hospital Discharge Survey, and death data in the Mortality Component of the National Vital Statistics System. Data regarding pulmonary function were obtained from the National Health and Nutrition Examination Surveys (NHANES) I (1971-1975) and III (1988-1994), and data regarding functional limitation were obtained from NHANES III, Phase 2 (1991-1994). RESULTS During 2000, an estimated 10 million U.S. adults reported physician-diagnosed COPD. However, data from NHANES III estimate that approximately 24 million U.S. adults have evidence of impaired lung function, indicating that COPD is underdiagnosed. During 2000, COPD was responsible for 8 million physician office and hospital outpatient visits, 1.5 million emergency department visits, 726,000 hospitalizations, and 119,000 deaths. During the period analyzed, the most substantial changes was the increase in the COPD death rate for women, from 20.1/100,000 in 1980 to 56.7/100,000 in 2000, compared with the more modest increase in the death rate for men, from 73.0/100,000 in 1980 to 82.6/100,000 in 2000. In 2000, for the first time, the number of women dying from COPD surpassed the number of men dying from COPD (59,936 versus 59,118). Another substantial change observed is that the proportion of the population aged < 55 years with mild or moderate COPD, on the basis of pulmonary function testing, decreased from 1971-1975 to 1988-1994, possibly indicating that the upward trends in COPD hospitalizations and mortality might not continue. INTERPRETATION COPD is a major cause of morbidity, mortality, and disability in the United States. Despite its ease of diagnosis, COPD remains an underdiagnosed disease, chiefly in its milder and more treatable form.
922 citations