[Chronic obstructive bronchitis: definitions, risk factors and prevention (author's transl)].

: Chronic obstructive bronchitis is defined as persistent diffuse airways obstruction frequently associated with chronic expectoration. This disease is particularly disabling and its medico-social burden implies that measures be taken. Risk factors of chronic obstructive bronchitis can be classified according to their presently known importance: tobacco, professional exposure, air pollution, viral and bacterial respiratory infections, poor socio-economic and cultural conditions, upper and lower airways infections during childhood, other environmental factors, genetic factors. Prevention needs that research be developed, in particular for factors, as hereditary ones, relations between childhood and adult respiratory diseases and characteristics of the "susceptible smokers". Knowledge of risk factors previously quoted allows to propose public-health actions. Firstly, true preventive action of general nature: fight against tobacco consumption, reduce atmospheric pollution, improve work and life conditions. Secondly, in order to prevent the disabling state of chronic bronchitis, it would be necessary to take care of patients at the initial state. A control trial is proposed to determine the level of symptoms and of reduction of ventilatory values at which an action is needed and the best "preventive therapeutical" protocol to be applied to these patients.