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

Abstract

Background: The gold standard for the diagnosis of chronic obstructive pulmonary disease (COPD) is spirometry, but there are barriers to its use in primary care. Aims: To externally validate the COPD Diagnostic Questionnaire (CDQ) as a diagnostic tool in patients at increased risk in Australian general practice and to compare its performance with other CDQ validation studies. Methods: Patients were recruited from 36 general practices in Sydney, Australia. Former or current smokers aged 40–85 years with no prior COPD diagnosis were invited to a case-finding appointment with the practice nurse. The CDQ was collected and pre- and postbronchodilator spirometry was performed. Cases for whom complete CDQ data were present and the spirometry met quality standards were analysed. Results: Of 1,631 patients who attended case-finding recruitment, 1,054 (65%) could be analysed. Spirometry showed 13% had COPD. The ability of the CDQ to discriminate between patients with and without COPD was fair, represented by the area under the receiver operating characteristic curve of 0.713. With a CDQ cut-off point value of 16.5 the sensitivity was 80% and specificity 47% and, at a cut-off point value of 19.5, the sensitivity was 63% and specificity 70%. Conclusions: The CDQ did not discriminate between patients with and without COPD accurately enough to use as a diagnostic tool in patients at increased risk of COPD in Australian general practice. Further research is needed on the value of the CDQ as a tool for selecting patients for spirometry.

Development of a simple screening tool for opportunistic COPD case finding in primary care in Latin America: The PUMA study

“…Different questionnaires have been developed for COPD case finding in primary care based on variables associated with increased or decreased risk of COPD . Recently, Stanley et al ., using the COPD Diagnostic Questionnaire, found that it did not perform well in identifying people with COPD when compared with spirometry. The ROC AUC of 0.71 being fair although higher than the one reported by other authors (sensitivity: 65%; specificity: 54%) with very low accuracy (ROC AUC 0.65).…”

“…However, extrapolation of the results to 1 year suggests that opportunistic approaches may be more efficient. Several studies have looked at developing screening tools to select persons at risk for further spirometric investigation . The simpler and more accurate the screening tool, the more useful for identifying patients for spirometry diagnosis.…”

Screening for Chronic Obstructive Pulmonary Disease

“…used to select high-risk patients for screening spirometry, which assigns scores for established risk factors including age, pack-years of smoking, and body mass index (BMI) as well as symptoms and allergy history ( Table 1). 14,17,[24][25][26][27][28] Possible scores range from 0 to 38 (higher scores associated with higher COPD risk), with highest scores attributed to older age (score 10 for Ն70 years), greater pack-years (score 7 for Ն50 pack-years), and lower BMI (score 5 for BMI). Two cut points (16.5 and 19.5) have been proposed to select patients for screening spirometry based on ROC curves from the original development study.…”

“…31 The CDQ has been externally validated in 5 fair-to goodquality diagnostic accuracy studies mainly focusing on primary care European and Australian populations. 14,17,[24][25][26] The study populations varied; 3 studies recruited solely current or ever-smokers from primary care, the general population, or both, 17,24,26 and 2 studies recruited patients from primary care clinics without regard to smoking history. 14,25 Chronic obstructive pulmonary disease was diagnosed by spirometry in 10.3% to 41.1% of participants in each of the 4 studies that reported this outcome, with the highest prevalence (41.1%) being reported in a study that required participants to be current smokers with at least a 10 pack-year history and have at least 1 respiratory symptom; these participants were essentially prescreened, thereby selecting for those most likely to have COPD.…”

To Measure Quality of Spirometry in Bihar

“…Accurate spirometry is an essential part of clinical practice in primary care and management 2 as well as monitoring of COPD and asthma. 4,5 Barriers to spirometry use in general practice include lack of expertise in performing spirometry, Poor access to a wellmaintained spirometers, Time consuming nature of pre-and post-BD spirometry, Low confidence in spirometry interpretation. Therefore, it is essential that those performing spirometry should be trained and able to demonstrate their competence to do the test, identify errors and interpret the results at the point of contact.…”