Lunar DPX-IQ, Operator'S Manual, Page: 149 / 166

DPX-IQ Operator’s Manual Comparison to Reference Population I-7
I.3 Age Adjustment
All Age-Matched comparisons use age regressions to calculate an expected BMD.
The subject’s BMD is compared with the expected BMD for a person of the same age
and gender in the reference population. Age regressions were determined from
subsets of the reference data of table I-3. The expected BMD values are based on the
studies of white reference females (table I-9).
Table I-11: Age regression for AP spine, lateral spine, femur and total body BMD in
white reference females.
Age n ROI BMD r
SEE
(g/cm
2
)
20–45 334 Ap Spine = 1.20-(0.0002 X Age) 0.00 0.139
45–65 665 Ap Spine = 1.71-(0.0113 X Age) 0.32 0.174
65+ 166 Ap Spine = 1.16-(0.0026 X Age) 0.20 0.170
20–45 171 Lateral Spine = 0.895-(0.0047 X Age) 0.25 0.118
45–65 125 Lateral Spine = 1.190-(0.0104 X Age) 0.46 0.118
65+ 86 Lateral Spine = 0.774-(0.0036 X Age) 0.00 0.155
Femur
20–45 345 Neck = 1.04-(0.0023 X Age) 0.13 0.121
45–65 370 Neck = 1.32-(0.0083 X Age) 0.34 0.127
65+ 109 Neck = 0.94-(0.0022 X Age) 0.08 0.127
Femur
20–45 345 Ward’s = 1.05-(0.0045 X Age) 0.21 0.144
40–65 370 Ward’s = 1.27-(0.0098 X Age) 0.36 0.145
65+ 109 Ward’s = 0.60-(0.0003 X Age) 0.00 0.147
Femur
20–45 345 Troch = 0.763+(0.0003 X Age) 0.00 0.108
45–65 370 Troch = 1.010-(0.0053 X Age) 0.24 0.117
65+ 109 Troch = 0.838-(0.0023 X Age) 0.08 0.126
20–45 146 Total Body= 1.13+(0.0005 X Age) 0.00 0.088
45–65 93 Total Body= 1.40-(0.0053 X Age) 0.33 0.084
65+ 54 Total Body= 1.06-(0.0003 X Age) 0.00 0.073