Table 6.

PedsQL™ 4.0 Generic Core Scales School Functioning Scale Score: Parent Proxy-Report Reliability and Validity

Age	Reliability		Validity
			Chronic Health Condition				Healthy Sample
	N	α	Mean	SD	% Floor	% Ceiling	Mean	SD	% Floor	% Ceiling	Chronic vs. Healthy Difference	Chronic vs. Healthy Effect Size
2 yrs	438	0.59	82.08	19.52	0.0	13.7	89.89	14.95	0.0	19.5	7.81*	0.52
3 yrs	592	0.69	70.71	24.41	0.8	10.7	88.31	16.05	0.1	23.4	17.60*	1.10
4 yrs	798	0.61	72.72	24.94	1.4	13.8	86.18	16.60	0.0	30.1	13.46*	0.81
5 yrs	908	0.74	69.04	22.62	1.2	10.5	78.47	18.93	0.0	17.6	9.43*	0.50
6 yrs	1,117	0.72	70.75	19.44	0.0	7.4	77.36	19.45	0.0	17.6	6.61*	0.34
7 yrs	1,068	0.74	66.23	22.64	1.1	7.2	75.65	19.95	0.1	17.1	9.42*	0.47
8 yrs	1,019	0.74	68.31	21.16	0.9	7.4	76.59	19.22	0.1	18.4	8.28*	0.43
9 yrs	962	0.73	65.31	21.68	0.4	5.8	74.98	20.02	0.0	16.9	9.67*	0.48
10 yrs	970	0.77	66.10	22.96	0.6	9.1	75.42	20.03	0.2	17.7	9.32*	0.47
11 yrs	774	0.77	67.02	23.06	0.4	6.0	76.65	20.16	0.2	20.6	9.63*	0.48
12 yrs	761	0.78	65.17	21.95	0.7	7.4	76.98	19.48	0.0	18.7	11.81*	0.61
13 yrs	699	0.76	67.22	21.91	0.0	9.6	75.31	21.13	0.0	20.6	8.09*	0.38
14 yrs	638	0.78	65.93	21.34	0.0	7.5	77.54	19.82	0.0	23.8	11.61*	0.59
15 yrs	613	0.79	64.53	21.69	0.8	6.4	76.25	20.42	0.0	22.8	11.72*	0.57
16 yrs	355	0.79	65.70	23.17	0.5	9.1	77.26	18.83	0.0	20.6	11.56*	0.61

Note: Total N = 11,712 for reliability, Total N = 11,106 for validity.

Higher values equal better health-related quality of life.

% Floor/Ceiling = the percentage of scores at the extremes of the scaling range.

Effect sizes are designated as small (.20), medium (.50), and large (.80).

*p < .001 (independent samples t-test).