Ethnic Variance in Prevalence of COPD among Smokers in a Real World Setting

Abstract

Introduction: Chronic Obstructive Pulmonary Disease (COPD) is characterized by persistent and progressive airflow limitation generally caused by prolonged cigarette smoking. Ethnic differences have been reported regarding COPD risk from smoking. The purpose of this study was to compare COPD prevalence in Hispanic and Caucasian smokers in a real-world setting. We studied consecutive patients referred to the community-based pulmonary practice. Hispanic and Caucasian smokers were included in the study. Methods: The clinical diagnosis of COPD was recorded from the chart. COPD was defined by PFT using GOLD criteria. Exclusion criteria were other ethnicities, non-smokers, and patients with a history of asthma /other pulmonary conditions. We reviewed a total of 1,313 consecutive PFTs of which 797 patients met our inclusion criteria. Results and Discussion: The prevalence of COPD among Hispanics was found to be lower by both clinical diagnosis as well as by spirometry compared to Caucasians (41.6% vs 54.2%). In Hispanics, clinical diagnosis was 91% higher by PFT, whereas for Caucasians, it was 6% lower. The odds of developing COPD (diagnosed based on FEV1/FVC ratio <70%) in the Caucasians are 4.1 times higher than Hispanics (Odds Ratio: 4.1; 95%CI: 2.8-5.9). Hispanic smokers have a lower prevalence of COPD both by the clinical diagnosis as well as by PFT. There is a significant disconnection between clinical and PFT diagnosis of COPD in Hispanic patients. Conclusion: The genetic basis of lower COPD risk and prevalence in Hispanics needs to be better understood. Spirometry threshold criteria for confirming a diagnosis of COPD may need to be modified based on ethnicity in clinical practice.