COPD prevalence in Argentina: The EPOC.AR study

Background: Although COPD is an increasing public health problem worldwide, its prevalence in Argentina had never been studied. Objectives: To estimate population prevalence and clinical features of COPD in a representative sample of adults ≥40 years in 4 cities of Argentina. Methods: Cross-sectional study of population selected at random through sampling by clusters.We applied a structured survey which included: home, COPD assessement, clinical, socio-demographic, risk factors, health condition, treatment and disease economic burden data. Spirometry (EasyOne ® ) pre-post bronchodilator was also performed and reviewed by a Committee that assessed their quality and rated cases. The GOLD obstructive and combined COPD assessment model was applied. Prevalence was estimated for total and for each city with 95%CI. Results: 2978 surveys and spirometry were carried out; 2548 spirometry had an acceptable quality (89.2%, 95%CI: 90,3-88,0). No significant differences in spirometry quality according to the urban area involved were seen. The overall prevalence of COPD found was 14.7% (95%CI:16.1%-13,0%) (M18.0%; F12.3%). 89.8% (CI:92.8%-86,7%) were GOLD 1/2 while 10.2% (CI:13.3%-7,2%) were GOLD 3/4. According to the combined index stage: A 60.9% (65.9%-56%); B: 28.8% (33.5%-24.2%); C: 5.4% (7.7%-3.1%) and D: 4.9% (7.0-2.7%). Distribution COPD stages were similar in all urban centers. Underdiagnosis was 75,8% (CI:80,2%-71,3%) and significant association with age, male gender, obesity, low education and socioeconomic level; heart disease, lung cancer and tuberculosis were found. Conclusions: Our study provides data of COPD prevalence in a representative sample of 4 Argentinean cities. It can be estimated more than 2.3 millon Argentines have COPD.