Voluntary lung function screening to reveal new COPD cases in southern Italy

Background: Underdiagnosis of COPD is a relevant issue, and most frequently involves patients at early stages of the disease. Physicians do not routinely recommend smokers to undergo spirometry, unless they are symptomatic. Aims: To investigate the effectiveness of voluntary lung function screening in bringing to light patients with previously unknown COPD and to evaluate the relationships among symptoms, smoking status, and airway obstruction. Methods: A voluntary screening study for COPD was conducted during two editions of the annual Fiera del Levante (2014 and 2015), an international trade fair in Bari. Subjects were eligible for the study if they fulfilled the following inclusion criteria: age ≥35 years, smoker/ex-smoker ≥5 pack-years (PYs), or at least one chronic respiratory symptom (cough, sputum production, shortness of breath, and wheezing). A free post-β2-agonist spirometry test was performed by trained physicians for each participant using portable spirometers. Post-β2-agonist forced expiratory volume in 1 second (FEV1):forced vital capacity ratio <0.7 was chosen to establish the diagnosis of COPD. Sensitivity, specificity, and negative and positive predictive values (NPVs and PPVs) of symptoms for the presence of obstruction were calculated. Results: A total of 1,920 individuals were eligible for the study; 188 subjects (9.8%) met COPD criteria. There was a 10.4% prevalence of COPD in subjects with one or more symptoms who had never smoked or smoked ≤5 PYs. Among COPD patients, prevalence of symptoms increased in the presence of FEV1<80%. COPD smokers were more symptomatic than smokers without COPD. Sensitivity and specificity in all subjects with one or more symptoms were 87% and 32%, respectively, whereas in smoker subgroups, sensitivity and specificity were 71% and 41% (≥5 PYs) and 74% and 35% (≥10 PYs), respectively. In all subjects, the presence of at least one symptom was associated with a low PPV for COPD of 11%, but a very high NPV (96%). These data did not change if the analysis was limited to smokers. Conclusion: Voluntary public lung function screening programs in Italy are effective, and may detect a large number of undiagnosed subjects with COPD in early stages. In our population, COPD symptoms had low specificity and PPV, even considering smokers only.