[Determination of spirometric values in a normal Chilean population over 5 years old, at sea level]

The interpretation of spirometric results requires reference values. Up to the moment, the reference values used in Chile are those of Knudson et al, obtained in a white North American population studied in Tucson, USA.

To obtain reference spirometric values from a Chilean population.

Maximal expiratory flow-volume curves were obtained from a randomly selected population of 850 healthy non-smoking subjects living at sea level, in cities without atmospheric pollution. Equipment and techniques were used according to the recommendations of the American Thoracic Society.

Linear regression equations were obtained, using age and height as independent variables and spirometric values as dependent variables, for both sexes and ages from 6 to 70 years old. Our values for forced vital capacity and forced expiratory volume were 9 to 18% and 10 to 15% higher than those reported by Knudson et al.

Chilean spirometric reference values differ from those used abroad, emphasizing the need to use local standards to interpret spirometric results.