PneumoLaus: Prevalence of Lung Function Abnormalities in a Sample of the General Population of Lausanne Abstract. Reduced lung function predicts increased mortality. The prevalence of spirometric abnormalities depends on their definition, the references values used and the use or not of bronchodilation. In the PneumoLaus study, conducted between 2014 and 2017 in a sample of the general population of Lausanne, prevalence of chronic obstruction was 3,8 %, of reversible obstruction 2,5 % and of possible restriction 2,2 %. These numbers are lower than in other population studies. Men had more abnormal spirometry results than women, and ever-smokers more than never-smokers. Two thirds of participants with chronic obstruction, most of which without respiratory symptoms, were not aware of any lung disease.