External validation of a COPD diagnostic questionnaire

Abstract

The aim of the present study was to determine the external validity of a recently developed questionnaire for the identification of patients at increased risk of airflow limitation in smokers from the general population in the provinces of Dutch and Belgian Limburg (regions surrounding Maastricht, the Netherlands).As part of a study on the early detection of airflow limitation and subsequent smoking cessation treatment (International Standard Randomised Controlled Trial Number: 64481813), the recently developed chronic obstructive pulmonary disease (COPD) diagnostic questionnaire was used in current smokers aged 40-70 yrs, with a smoking history of o10 pack-yrs, who reported one or more respiratory symptom (cough, sputum production or dyspnoea), but who had no diagnosis of a respiratory disease (COPD or asthma). Spirometry performed according to American Thoracic Society/European Respiratory Society criteria served as a reference test.Of the 676 subjects who entered the analyses, 398 showed normal lung function and 278 had a diagnosis of COPD (post-bronchodilator forced expiratory volume in one second/forced vital capacity of ,0.70). The ability of the COPD diagnostic questionnaire to discriminate between subjects with and without COPD was poor (area under the receiver operating characteristic curve of 0.65).In a high-risk population consisting of middle-aged current smokers with a smoking history of o10 pack-yrs, the chronic obstructive pulmonary disease diagnostic questionnaire is probably not useful as a diagnostic tool for the identification of patients with an increased risk of airflow limitation.

Validation of the COPD Diagnostic Questionnaire in an Australian general practice cohort: a cross-sectional study

“…The ROC AUC of 0.713 is fair, and is higher than that in the study by Kotz et al who considered their ROC AUC of 0.65 to be very low. 20,25 The ROCAUC in this study is less than two other external validation studies and less than the original study which had an ROC AUC of 0.816. 12,19,21 The ROCAUC in this study is closer to 0.5 than 1.0, where a test with an area under the curve of 1 would represent a perfect test with no overlap between true positives and false positives and the optimal operating point corresponding to the upper left-hand corner of the ROC graph ( Figure 2).…”

“…12,19,21 This is shown in Tables 2 and 3, with results of the other studies derived from their respective papers. 12,15,[19][20][21] Sensitivity and specificity at the cut-off point value of 16.5 (cutoff point A) were 79.7% and 46.8%, respectively and, at 19.5 (cutoff point B), the sensitivity and specificity were 63.0% and 70.1%, respectively. When compared with other validation studies (Table 3), sensitivity was lower at both cut-off points.…”

“…18 Although the CDQ was not developed as a diagnostic tool, it has been validated in comparison with spirometry in subjects selected from primary care settings in Europe and Australia and hospital outpatient clinics in Japan. 15,[19][20][21] Two of these studies investigated the validity of the Piko-6 ® flow meter (a form of microspirometry) as a screening tool for COPD diagnosis in primary care. 15,21 These studies also validated the CDQ and compared it with micro-spirometry.…”

“…21 The analysis methods were based on a protocol outlined by Price et al 12 The study measured the relationship between CDQ scores and COPD proportions determined by spirometry and these results were compared with the findings in the study by Price et al, one Australian and three international external validation studies. 12,15,[19][20][21] The variability in how the CDQ performed in this and other external validation studies was examined.…”

Laryngeal Measurements and Diagnostic Tools for Diagnosis of Chronic Obstructive Pulmonary Disease

“…Various symptoms and exploratory signs of COPD have been studied, 2,3 but findings from a physical examination are rarely diagnostic. 4 Questionnaires, such as a COPD diagnostic questionnaire 5,6 (which addresses allergies and lower respiratory track symptoms, as well as cough, age, smoking pack-year, body mass index) and the Lung Function Questionnaire 7 (which addresses age, smoking history, frequency of productive cough, chest sounds, and breathing difficulty during physical activity), have been proposed to select individuals for spirometry because of their validity and simple application in family medicine practice. In 2000 laryngeal height began to be evaluated as a diagnostic sign 8 without much continuity.…”