REFERENCE SPIROMETRIC VALUES FOR THE CHIL EAN POPULATION AT SEA-LEVEL

Background: The interpretation of spirometric results requires referen ce values. Up to the moment, the reference values used in Chile are th ose of Knudson et al, obtained in a white North American population st udied in Tucson, USA. Aim: To obtain reference spirometric values from a Chilean population. Subjects and methods: Maximal expiratory flow-v olume curves were obtained from a randomly selected population of 850 healthy non-smoking subjects living at sea level, in cities without at mospheric pollution. Equipment and techniques were used according to t he recommendations of the American Thoracic Society. Results: Linear r egression equations were obtained, using age and height as independent variables and spirometric values as dependent variables, for both sex es and ages from 6 to 70 years old. Our values for forced vital capaci ty and forced expiratory volume were 9 to 18% and 10 to 15% higher tha n those reported by Knudson et al. Conclusions: Chilean spirometric re ference values differ from those used abroad, emphasizing the need to use local standards to interpret spirometric results.