Incidence of reported diagnosis of chronic bronchitis/emphysema on an italian general population sample

Rationale: to assess the effect of risk factors on Chronic Obstructive Pulmonary Disease (COPD) incidence in a general population sample. Methods: we studied a general population sample enrolled in a cross-sectional study carried out in Central Italy (Pisa) in 1991-1993(baseline). Part of the same sample was enrolled in a recent cross-sectional study within the framework of the European Union funded project IMCA2 (Indicators for Monitoring COPD and Asthma in the EU) (follow-up). In both studies, the subjects filled in a standardized questionnaire about health status and risk factors and performed spirometry test. For the analyses, we selected a longitudinal adult sub-sample (n=547; initial age range: 20-77, female 53.9%) without airways obstruction, according to 2005 ATS/ERS criteria, and with percent predicted Forced Expiratory Volume in 1 s. (FEV1) > 80% in the 1991-1993 survey. On this sub-sample we assessed the incidence of COPD at follow-up as reported diagnosis of COPD, chronic bronchitis or emphysema. We used bivariate analyses to assess the association between COPD incidence and baseline risk factors (age, gender, smoking habits, occupational exposure, percent predicted FEV1). Increased risk was assessed using Logistic Regression (LR) with COPD incidence as the dependent variable and the same risk factors as independent ones.