PT  - JOURNAL ARTICLE
AU  - Yunus Çolak
AU  - Shoaib Afzal
AU  - Børge G. Nordestgaard
AU  - Peter Lange
AU  - Jørgen Vestbo
TI  - Challenges in defining early COPD in the general population: Findings from the Copenhagen General Population Study
AID  - 10.1183/13993003.congress-2020.1398
DP  - 2020 Sep 07
TA  - European Respiratory Journal
PG  - 1398
VI  - 56
IP  - suppl 64
4099  - http://erj.ersjournals.com/content/56/suppl_64/1398.short
4100  - http://erj.ersjournals.com/content/56/suppl_64/1398.full
SO  - Eur Respir J2020 Sep 07; 56
AB  - Background: Individuals that develop chronic obstructive pulmonary disease (COPD) could be identified at an early age before disease onset. We aimed at analysing outcomes depending on the definition of early COPD, as we hypothesised that choice of age and smoking exposure would impact on subsequent risk.Methods:105,143 adults from a population-based cohort, of whom 16,383 had lung function measured 10 years later. Early COPD definition relied on age, smoking, and forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC)<lower limit of normal (LLN). Outcomes included COPD at final examination (FE1/FVC<0.70 and FEV1<80% predicted) and hospitalisations.Results:5,777 were aged <50 at baseline examination, of whom 273(5%) developed COPD. Among 5,777 individuals, 12% had FEV1/FVC<LLN in smokers ≥10 pack-years, 7% in smokers <10 pack-years, and 6% in never-smokers. Among smokers ≥10 pack-years, 43% developed COPD in those with versus 5% in those without FEV1/FVC<LLN. Corresponding numbers were 27% and 2% in smokers <10 pack-years, and 20% and 1% in never-smokers, respectively. Changing smoking requirement from ≥10 to >0 pack-years reduced sensitivity slightly without affecting specificity, or positive- or negative predictive values. In individuals aged <50 with FEV1/FVC<LLN, odds ratios for subsequent COPD were 13.1(95% CI:9.07-18.8) using ≥10 pack-years and 14.9(11.0-20.4) using >0 pack-years. Corresponding hazard ratios for hospitalisations were 8.74(95% CI:4.55-16.8) and 8.42(4.84-14.6), respectively.Conclusion: Defining early COPD is challenging. Choice of age and smoking exposure will not only impact on prevalence of early COPD but also on subsequent risk.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 1398.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).