Which is the Best Screening Strategy for COPD among Smokers in Primary Care?

Abstract

We developed a questionnaire to detect cases of chronic obstructive pulmonary disease (COPD) and compared its reliability with other strategies. In order to develop the new questionnaire (COPD screening questionnaire from Terrassa [EGARPOC]) we used data from an epidemiological study on the prevalence of COPD in smokers and calculated the odds ratio for each variable showing significance for the diagnosis of COPD on regression analysis. For comparison among questionnaires and the portable spirometer COPD-6, a cross-sectional multicenter study was performed. The study included 407 smokers or ex-smokers over the age of 40 years with no known diagnosis of COPD, who completed the different questionnaires (EGARPOC, Respiratory Health Screening Questionnaire, COPD-population screener and 2 questions) and underwent spirometry with the COPD-6. We determined the sensitivity, specificity, positive and negative predictive values (S, Sp, PPV and NPV, respectively) and the area under the receiver operating characteristic ROC curve (AUC ROC) of all the questionnaires and the different COPD-6 cut-offs. The prevalence of COPD was 26.3%. The EGARPOC questionnaire showed an S of 81.8%, an Sp of 70.6%, and an NPV of 91.8%; 73.3% of individuals were correctly classified, and the AUC ROC was 0.841. On comparing the questionnaires by the Chi-square test, the 2-question questionnaire showed the worst discrimination; while with an optimal cut-off of forced expiratory volume in one 1 second (FEV)/FEV of 0.78, the COPD-6 was significantly better than the questionnaires in the detection of COPD. Using a cut-off of FEV/FEV of 0.78 the COPD-6 was found to be the best screening tool for COPD in primary care compared to the questionnaires tested, which did not show differences among them.

Classifying the Severity of COPD: Are We There Yet? Editorial for “Coton, S. et al. Severity of Airflow Obstruction in Chronic Obstructive Pulmonary Disease (COPD): Proposal for a New Classification”

“…The correlation of FEV 1 to FVC in the current study was striking as they report a correlation coefficient of 0.9; moreover, as previously reported, FVC is prognostic of survival (10). It is interesting to note that as FEV 1 and FEV 1 /FVC are nearly equivalent in terms of identification of obstruction, association to exacerbation and dyspnea and the same is most certainly the case for FVC and by extension FEV 6 (14). Why is this important?…”

What have we learned from observational studies and clinical trials of mild to moderate COPD?

“…The study included 1738 subjects over the age of 45 with a history of smoking and found a rate of underdiagnosis of 73%. Recently, the same group performed a case-finding study in smokers or former smokers older than 40 years and found a prevalence of COPD of 26.7%, with the majority of patients being in GOLD stages I and II (42.1 and 49.1%, respectively) [ 21 ]. Up to 29% of patients with underdiagnosed COPD are asymptomatic [ 22 ], which contributes to late detection.…”

“…In addition, patients often under-recognize the significance of respiratory symptoms, or they may accept that their symptoms are caused by smoking and ignore them rather than consult. Another cause for underdiagnosis might also be a deficient active search for COPD by health care professionals [ 21 ]. Some of the diagnostic initiatives that have been tested to improve COPD diagnosis are early detection programs [ 23 ] and other tools such as the use of peak-flow meters or mini spirometers [ 24 ], and screening questionnaires [ 21 , 25 ].…”

Point of care microspirometry to facilitate the COPD diagnostic process in primary care: a clustered randomised trial

“…Studies that focussed on screening (i.e., case finding) for COPD found microspirometry to be a valid method and significantly better than using screening questionnaires. 10 , 13 – 15 But what if microspirometry is used in routine general practice settings as a POC test for COPD? This could potentially reduce underdiagnosis of COPD while avoiding the need for screening initiatives to identify missed COPD cases in primary care populations.…”