Measurement of FEF25-75% and FEF75% does not contribute to clinical decision making.
The aim of this study was to determine the added value of measuring the forced expiratory flow at 25-75% of forced vital capacity (FVC) (FEF25-75%) and flow when 75% of FVC has been exhaled (FEF75%) over and above the measurement of the forced expiratory volume in 1 s (FEV1), FVC and FEV1/FVC ratio. We used spirometric measurements of FEV1, FVC and FEF25-75% from 11 654 white males and 11 113 white females, aged 3-94 years, routinely tested in the pulmonary function laboratories of four tertiary hospitals. FEF75% was available in 8254 males and 7407 females. Predicted values and lower limits of normal, defined as the fifth percentile, were calculated for FEV1, FVC, FEV1/FVC ratio, FEF25-75% and FEF75% using prediction equations from the Global Lung Function Initiative. There was very little discordance in classifying test results. FEF25-75% and FEF75% were below the normal range in only 2.75% and 1.29% of cases, respectively, whereas FEV1, FVC and FEV1/FVC ratio were within normal limits. Airways obstruction went undetected by FEF25-75% in 2.9% of cases and by FEF75% in 12.3% of cases. Maximum mid-expiratory flow and flow towards the end of the forced expiratory manoeuvre do not contribute usefully to clinical decision making over and above information from FEV1, FVC and FEV1/FVC ratio.
Erasmus Medical Centre, Erasmus University, Rotterdam, The Netherlands.
Philip H
PH
Quanjer
Daniel J
DJ
Weiner
Jeffrey J
JJ
Pretto
Danny J
DJ
Brazzale
Piotr W
PW
Boros
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D002648:Child; D002675:Child, Preschool; D003657:Decision Making; D020000:Decision Support Systems, Clinical; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D010414:Pennsylvania; D011044:Poland; D011237:Predictive Value of Tests; D012129:Respiratory Function Tests / Q000592:standards*; D012189:Retrospective Studies; D013147:Spirometry; D014797:Vital Capacity; D055815:Young Adult