ISSN:
1432-1750
Keywords:
Maximal expiratory flow-volume curves
;
Maximal midexpiratory flow rate
;
Respiratory function tests
;
Airway obstruction
;
Lung diseases
;
Obstructive
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Background: Forced midexpiratory time (FET25–75%), the time required to exhale from 25 to 75% of forced vital capacity (FVC), has been advocated as a relatively volume-independent measure of obstruction. Previous estimates of normal FET25–75% have not systematically studied the effect of age, height, sex, and smoking history. Methods: We analyzed flow-volume loops from 369 normal lifetime nonsmokers and smokers, a random sample of the population of Michigan. Linear models including age and/or height were considered, with and without logarithmic transformation. Results: The best models used age, or age and height, and no transformation. Age and height contributed much less to the variability of FET25–75% than to spirometric flows previously investigated. The largest r 2 was found in the male smokers, with the largest contribution from age, suggesting a smoking effect. Conclusions: As age was the major contributor to the value of FET25–75% and that contribution was small, we suggest the use of simplified ages-tratified reference values derived from our data.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00167599
Permalink
