Welch Allyn CardioPerfect Workstation SpiroPerfect Module - User Manual - Manual (Page 70)

CardioPerfect Workstation
SpiroPerfect Module
– User Manual
DIR 80012334 Ver. F 70 / 95
For a listing of the parameters included in each norm, see section 12.1 Norm Profiles.
12.5 Lung Age
Lung age is a calculated value based on a patient’s demographics and spirometric
performance. This provides a relative indication of the health of the patient's lungs. This value
is used primarily to encourage smoking cessation.
The SpiroPerfect spirometer, calculates lung age values according to the document cited in
Reference 4 (Morris, 1985). For single-effort tests, lung age is based on the current effort.
Otherwise, it is based on the patient’s “best” pre effort as defined in the settings.
Lung age calculations are provided only for patients 20 and older. For patients older than 84
years the lung age is extrapolated. This limitation is derived from the subject population on
which Morris based his research. The lung age is one floating point number in years: the
average of the 4 formulas in the Morris article (FVC, FEV1, FEF25-75%, and FEF0.2-1.2).
Specifically, lung age is calculated as follows:
Gender Lung Age Formula
Men [5.920 (height) – 40.000 (FVC) – 169.640 +
2.870 (height) – 31.250 (FEV1) – 39.375 +
2.319 (height) – 21.277 (FEF200-1200) + 42.766 +
1.044 (height) – 22.222 (FEF25%-75%) + 55.844 ] / 4
Women [4.792 (height) – 41.667 (FVC) – 118.833 +
3.560 (height) – 40.000 (FEV1) – 77.280 +
4.028 (height) – 27.778 (FEF200-1200) – 70.333 +
2.000 (height) – 33.333 (FEF25%-75%)+18.367 ] / 4
height in inches
12.6 Ethnic group correction
Studies have demonstrated that expected values for certain spirometric parameters can vary
significantly from one ethnic group to another. Some norm studies include separate
regression equations for different races but most others do not.
In the latter case Welch Allyn CardioPerfect applies ethnic group correction to all
non-Caucasian adult patients in the prediction formulas. The interpretation area will state if
the norm values are extrapolated. The ATS (for blacks) or NIOSH (for Asians)
recommendations will be used for extrapolation.
Race Choices
FVC&FEV1 Recommendation Source
Caucasian
Black
Asian
Hispanic
Native American No adjustment
88%
94%
No adjustment
No adjustment -
ATS
NIOSH
None found
None found
Note
Race adjustment applies for adults only and applies to all supported parameters
within the norm study.
If a race adjustment percentage is used, the same adjustment is applied to the LLN
value.