Impact of farm modernity on the prevalence of chronic obstructive pulmonary disease in dairy farmers

Dairy farming is associated with an excess of chronic obstructive pulmonary disease (COPD). The dairy industry has been changing for the past three decades with larger, more efficient farms and potentially less exposure to agents involved in COPD development. However, the impact of farm modernisation on COPD prevalence is unknown. We studied respiratory symptoms, respiratory function by spirometry and tobacco smoking in 575 male dairy farmers working either in traditional or in modern farms in the French Doubs region. COPD was defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criterion (forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.70) and by the Quanjer reference equation (FEV1/FVC