The data of consecutive adult smoker patients, referred to the Clínica del Pulmón (Santa Cruz, Bolivia), between May 2018 and June 2018, will be analyzed. All the patients are current or ex-smokers, complaining of dyspnea, cough or expectorations. Spirometry measurements will be performed with a Medisoft Body Box 5500 by one highly trained and experienced pulmonologist according to the guidelines of the ATS/ERS.
The criteria used to detect airway obstruction are either the fixed cut-off points according to GOLD recommendations (FEV1/FVC\<0.70) or the lower limit of normal (FEV1/FVC\<LLN). These indices will be compared to a fixed cut-off FEV1/FEV6 \<0.73 as proposed by Vandevoorde et al. or to a FEV1/FV6 ration \< LLN. Reference equations used are those of Caucasians from the NHANES III survey.
Statistical tests will be done using IBM SPSS 24 software. Cohen's κ will be used to determine if there is an agreement between the definitions of airway obstruction.
