Table 5.

Pain interference age DIF analysis

Short form	Item stem	Age DIF (5–7 vs. 8–17)		Age DIF (8–12 vs. 13–17)
		X2 (df)	p	X2 (df)	p
SF	It was hard for my child to have fun when he/she had pain.	5.4 (5)	0.37	4.9 (5)	0.42
SF	It was hard for my child to pay attention when he/she had pain.	4.3 (5)	0.51	5.4 (5)	0.36
SF	My child had trouble doing schoolwork when he/she had pain.	4.3 (5)	0.51	4.4 (5)	0.49
SF	My child had trouble sleeping when he/she had pain.	5.2 (5)	0.39	1.1 (5)	0.95
SF	It was hard for my child to run when he/she had pain.	10.6 (5)	0.06	5.3 (5)	0.39
SF	It was hard for my child to walk one block when he/she had pain.	7.6 (5)	0.18	10.0 (5)	0.08
SF	My child felt angry when he/she had pain.	8.9 (4)	0.06	1.7 (4)	0.79
	My child hurt all over his/her body.	6.0 (4)	0.20	3.6 (4)	0.47
	It was hard for my child to remember things when he/she had pain.	**	**	**	**
SF	It was hard for my child to stay standing when he/she had pain.	**	**	**	**
	It was hard for my child to get along with other people when he/she had pain.	**	**	**	**
	My child hurt a lot.	**	**	**	**
	My child missed school when he/she had pain.	**	**	**	**

^**Form 4 items are not included due to insufficient sample size.