Participants
respiratory diseases
RESPIRATORY DISEASE
The participants were selected at the screening visit (V0) by the referring family doctors and nurses among patients attending their primary healthcare centres for any reason between August 2012 and December 2013 from the population assigned to 20 Catalan Institute of Health primary healthcare centres (12 urban and eight rural) in Tarragona province (Catalonia, Spain).Inclusion criteria: Active smokers aged 35–70 years, with a cumulative consumption > 10 packs-year. Exclusion criteria: History of respiratory diseases, spirometry performed within the previous 12 months, or inability to follow-up the study protocol.