Prevalence of COPD among symptomatic patients in a primary care setting

Spirometry is recognized as the gold standard assessment for the diagnosis of COPD. However, spirometry continues to be underused, perpetuating the underdiagnosis of COPD. The aim of this study was to evaluate the prevalence of COPD in a primary care setting in patients with a smoking history and self-reported chronic bronchitis symptoms.

This was a multi-center, cross-sectional study. The primary assessment was the percentage of patients with airway obstruction (post-bronchodilator FEV(1)/FVC ratio < or = 0.70) compared to those without obstruction (post-bronchodilator FEV(1)/FVC ratio > 0.70).

Airflow obstruction consistent with COPD was confirmed in 26% of patients (mean age 52.9 years, FEV(1) 81.4% predicted and smoking history 39.8 pack-years) that reported chronic bronchitis symptoms. Airflow obstruction increased with age and smoking history. Slight or moderate dyspnea was reported by 68% of patients and the majority had not talked to their doctor about cough and continued to smoke.

Patients were evaluated at a single visit. The definition of airway obstruction used may have lead to overdiagnosis in patients aged 70 and older.

This study confirms that many patients with COPD remain undiagnosed in the primary care setting. Evaluation of spirometry in patients with a smoking history and chronic bronchitis symptoms can aid in the diagnosis of COPD, allowing earlier treatment thereby reducing the burden of this debilitating disease.

Study code ADC109043; clinicaltrials.gov #NCT00442468.