- Smokers will require a minimum of 10 pkyr history and currently smoking at least a pack per day. The smokers without symptoms of COPD must demonstrate a pulmonary function with an FEV1 > 80%. The FEV1/FVC ratio may be less than .7 however they can not demonstrate symptoms of chronic bronchitis by medical history. Smokers with symptoms must demonstrate an FEV1 < 80% and FEV1/FVC <.7.