A Combined Ultrasonic Backscatter Parameter for Bone Status Evaluation in Neonates

Table 7

The optimal models for predicting CAS.

	Independent variables	RMSE	Adjusted R^2
3.5 MHz	GA	0.26	0.443
	0.008GA – 3.463
5.0 MHz	GA	0.25	0.405
	0.007GA – 2.705
7.5 MHz	GA, H, CA	0.33	0.403
	0.006GA+ 0.028H+ 0.172CA – 5.508

GA gestational age, H head circumference, CA serum calcium, RMSE root mean square error of the regression, R² square of the adjusted correlation coefficient of the regression. P < 0.001 for GA, P = 0.003 for H, P = 0.033 for CA.