Background: The Burden of Obstructive Lung Disease study showed that in Germany, to confirm the diagnosis of chronic obstructive lung disease (COPD) in one subject, eight people ≥ 40 years of age have to be screened. The number-needed-to-screen (NNS) increased to 18 for identifying a patient with COPD ≥ GOLD stage II. These high numbers limit the cost-effectiveness of COPD screening by population spirometry. We investigated in a primary care setting whether using two simple questions regarding smoking status and presence of cough and/or dyspnea may help to preselect patients for proper diagnosis of COPD.
Methods: A total of 1088 patients aged ≥ 40 yrs without a history of chronic lung disease, who were either current or ex-smokers and complained of cough and/or dyspnea, were examined by respiratory physicians. Spirometry was carried out to confirm COPD diagnosis and severity.
Results: A total of 61.6% of patients were male. Mean smoking history was 31.8 pack-yrs. In 516 patients (47.4%), a diagnosis of COPD was confirmed. Among these, 379 (34.8% of total) had at least GOLD stage II COPD, while 89 (8.2% of total) had advanced disease (GOLD stages III/IV). COPD prevalence was significantly associated with age and the extent of cigarette smoke exposure.
Conclusions: Two questions regarding smoking status and presence of cough and/or dyspnea enabled general practitioners to select patients at risk for COPD for subsequent spirometry. This preselection reduced the NNS to 2.1 for identifying a COPD patient, and to 2.9 for identifying a patient of at least GOLD stage II.