Overview :

The Forced midexpiratory flow rate (FEF25-75%) is the mean forced expiratory flow during the middle half of the forced vital capacity (FVC).

Alternative term: MMEF

FEF(25-75%) in liters per second for White males 15-79 years (Cherniack, 1972) =

= (0.05948 * (height in inches)) - (0.037 * (age in years)) + 2.61187

FEF(25-75%) in liters/second for White females 15-79 years (Cherniack, 1972) =

= (0.04931 * (height in inches)) - (0.03120 * (age in years)) + 2.25610

FEF(25-75%) in liters per second for Hispanic males 25-80 years (Coultas, 1988) =

= (2.0718 * (height in meters)) - (0.0441 * (age in years)) + 2.1769

FEF(25-75%) in liters/second for Hispanic females 25-80 years (Coultas, 1988) =

= (1.9552 * (height in meters)) - (0.0365 * (age in years)) - 1.5798

FEF(25-75%) in liters per second for White males 15-91 years (Crapo et al., 1981) =

=  (0.0204 * (height in cm)) - (0.0380 * (age in years)) + 2.133

FEF(25-75%) in liters/second for White females15-84 years (Crapo et al., 1981) =

=   (0.0154 * (height in cm)) - (0.0460 * (age in years)) + 2.683

FEF(25-75%) in liters/second for Hispanic males 25-75 years (Crapo, 1990) =

= (0.0453 * (height in cm)) - (0.0389 * (age in years)) - 2.0574

FEF(25-75%) in liters/second for Hispanic females 20-80 years (Crapo, 1990)  =

=  (0.0330 * (height in cm)) - (0.0361 * (age in years)) - 0.3758

FEF(25-75%) in liters/second for White males 25-85 years (Knudson, 1983) =

= (0.0579 * (height in cm)) - (0.0363 * (age in years)) - 4.5175

FEF(25-75%) in liters/second for White females 20-88 years (Knudson, 1983) =

= (0.0209 * (height in cm)) - (0.0344 * (age in years)) + 1.1277

FEF(25-75%) in liters per second for White males 20-84 (Morris, 1971)=

= (0.047 * (height in inches)) - (0.045 * (age in years)) + 2.513

FEF(25-75%) in liters per second for White females 20-84 years (Morris, 1971)=

= (0.06 * (height in inches)) - (0.030 * (age in years)) + 0.551

FEF(25-75%) in liters/second for Black males 20-92 years years (Stinson, 1981) =

= (0.132 * (height in inches)) - (0.02 * (age in years)) - 4.611

FEF(25-75%) in liters/second for Black females 20-92 years (Stinson, 1981) =

= (0.043 * (height in inches)) - (0.028 * (age in years)) + 1.061

Interpretation:

• The FEF(25-75%) reflects the severity of pulmonary impairment in obstruction.

• In small airway disease: FVC is >= 81% of predicted, but FEF(25-75%) < 65%.

Cherniack RM, Raber MB. Normal standards for ventilatory function using an automated wedge spirometer. Am Review Respir Dis. 1972; 106: 38-46 (Table 3, page 42).

Coultas DB, Howard CA, et al. Spirometric prediction equations for Hispanic children and adults in New Mexico. Am Rev Respir Dis. 1988; 138: 1386-1392. (Table 4, page 1390).

Crapo RO, Morris AH, Gardner RM. Reference spirometric values using techniques and equipment that meet ATS recommendations. Am Rev Respir Dis 1981; 123:659-664.

Crapo RO, Jensen RL, et al. Normal spirometric values in healthy Hispanic Americans. Chest. 1990; 98: 1435-1439.

Ewald G, McKenzie C (editors). Manual of Medical Therapeutics, 28th edition. Little, Brown and Company. 1995. page 242

Knudson RJ, Lebowitz MD, et al. Changes in the normal expiratory flow-volume curve with growth and aging. Am Rev Respir Dis. 1983; 127: 725-734.

Morris JF, Koski A, Johnson LC. Spirometric standards for healthy nonsmoking adults. Am Rev Respir Dis. 1971; 103: 57-67.

Ruppel GE. Manual of Pulmonary Function Testing, Sixth Edition. Mosby. 1994. pages 461-462.

Stinson JM, McPherson GL, et al. Spirometric standards for healthy Black adults. J National Medical Association. 1981; 73: 729-733

Wanger J. Pulmonary Function Testing. A Practical Approach. Second Edition.  Williams & Wilkins. 1996. Table A4.4, page 276.