All study data are ultimately stored in the COPDGene Data Coordinating Core (DCC) at the Division of Biostatistics and Bioinformatics at National Jewish Health. Data are entered by each site through a web-accessible system. Verification of eligibility is completed via a website questionnaire after subjects sign the research consent form, and subjects are tracked for completion of all study data. If a participant is excluded or discontinues during or after the study procedures, the specific exclusion or discontinuation reason is recorded in the database.
