Table 4. The estimation of factors affecting NSA using Linear Mixed Models.

Factors	NSA (GMFCS level I-III)			NSA (GMFCS level IV)			NSA (GMFCS level V)
	Estimation	SE	P value	Estimation	SE	P value	Estimation	SE	P value
Intercept	148.1	1.1	< 0.001	154.1	1.8	< 0.001	161.4	1.5	< 0.001
Follow up	0.05	0.15	0.755	3.4	0.8	< 0.001	1.1	0.7	0.1
Sex	-1.3	1.2	0.272	-0.7	1.9	0.711	-2.5	1.6	0.1

NSA, neck shaft angle; GMFCS, gross motor function classification system; SE, standard error.