Participants who met the inclusion/exclusion criteria detailed below and agreed to participate, underwent annual LDCT and pulmonary function tests until age 75 or 15 years of smoking abstinence, whichever came first. The study protocol was approved by the Ethics Committee of the Fundación Jiménez Díaz (ER2\_EO180-19\_FJD-HGV) and all participants signed their informed consent.
Inclusion criteria were males or females, 55-75 years of age, current or former smokers (Less than 15 years of abstinence) with a cumulative smoking exposure of greather than 30 pack-years and a diagnosis of COPD according to the GOLD guidelines and/or emphysema identified by LDCT. Individuals with a recent history of cancer (except non-melanoma skin cancer or carcinoma in situ) as well as those with other medical conditions that posed a significant risk of death were excluded.
