Service manual

IQmark Digital Spirometer Operation Manual
88
I. Adjustments to Reference Values Equations
According to the ATS recommendations specified in Reference 2 and studies cited by Enright
(Reference 23), Black and Asian adults have FVC and FEV
1
values that are approximately
15% below that of Caucasians. Black children have FVC and FEV
1
values that are
approximately 12% lower than Caucasian children’s values.
The software makes the following adjustments to the reference values for Asian and Black
patients if the reference equations are only for a white patient population.
Measurement Scale Factor
FEV
1
0.85
FVC 0.85
FEV
1
/FVC % None
Measurement Scale Factor
FEV
1
0.88
FVC 0.88
FEV
1
/FVC % None
The software does not use the above correction factors if the reference equations in use
include the patient’s race, e.g., Hankinson.
Not all race scale factors have been documented. At the time of this printing, many races
have had some published recommendations. The latest recommendations are as follows:
1.00 - American Indian, Caucasian, Eskimo, European-American, Hawaiian, Hispanic,
Indian, Italian, Iranian, Jordanian, Polynesian, Saudi Arabian, South American, Spanish,
White
0.85 - Asian, African, African-American, Black, Cambodian, Chinese, East Indian Pakistani,
Filipino, Jamaican, Japanese, Korean, Laotian, Vietnamese
However, a recent paper by Korotzer et al (Am. J. Respir. Crit. Care Med. 2000 161: 1101-
1108) suggests a 0.93 correction for Asian-American.
Correction Of Reference Values For Blacks And Asians
Correction Of Reference Values For Black Children
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