[Normal spirometric values in the Chilean population].

Spirometry began to be used by Chilean clinicians after the end of the II World War. Since then and over 50 years foreign standards have been usually used as reference normal values for the Chilean population. According to the current guidelines for spirometry (Chilean Society of Respiratory Diseases, 1988), Knudson et al's values are being used as reference for both children and adults. However, in the last years several studies have shown that Knudson et al's equations underestimate in more than 10% the spirometric values in normal Chilean population. This discrepancy could be explained by ethnical differences. Fortunately, the efforts carried out to obtain reference spirometric values from the Chilean population have yielded linear regression equations for 6 to 70 years old people. The present national reference values should replace the foreign ones. This replacement should have a positive impact in the use of spirometry for evaluating clinical ventilatory limitations as well as for legal disability purposes.