Table 1.

PedsQL™ 4.0 Generic Core Scales Total 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	1,277	0.89	79.16	17.61	0.0	8.6	88.14	12.11	0.0	15.8	8.98*	0.74
3 yrs	1,232	0.90	76.90	18.15	0.0	5.7	87.96	11.63	0.0	13.4	11.06*	0.95
4 yrs	1,177	0.90	76.03	19.34	0.0	4.6	87.37	12.67	0.0	14.1	11.34*	0.90
5 yrs	893	0.92	70.57	19.19	0.4	1.6	79.91	15.85	0.0	7.6	9.34*	0.59
6 yrs	1,105	0.91	72.98	17.14	0.0	2.1	79.74	15.86	0.0	5.5	6.76*	0.43
7 yrs	1,061	0.92	70.04	19.12	0.0	2.7	78.59	16.53	0.0	8.0	8.55*	0.52
8 yrs	1,009	0.92	72.51	17.58	0.0	3.4	80.23	15.94	0.0	8.9	7.72*	0.48
9 yrs	952	0.92	69.34	18.32	0.4	0.7	78.89	17.07	0.0	7.5	9.55*	0.56
10 yrs	955	0.92	70.23	18.51	0.0	2.8	80.68	15.73	0.0	8.2	10.45*	0.66
11 yrs	768	0.93	71.26	18.71	0.0	2.1	80.95	16.39	0.0	9.4	9.69*	0.59
12 yrs	753	0.93	68.75	19.14	0.0	1.5	80.77	16.39	0.0	8.7	12.02*	0.73
13 yrs	692	0.93	71.11	18.24	0.0	1.4	80.24	17.02	0.0	9.8	9.13*	0.54
14 yrs	633	0.92	69.09	18.39	0.0	1.8	82.32	14.94	0.0	9.1	13.23*	0.89
15 yrs	605	0.93	71.20	17.48	0.4	1.2	80.67	16.42	0.0	12.7	9.47*	0.58
16 yrs	352	0.93	69.13	19.35	0.0	1.0	82.73	14.43	0.0	10.9	13.60*	0.94

Note: Total N = 13,464 for reliability, Total N = 13,028 for validity.

For the reliability analysis for the 2 to 4 age subgroups, items on the School Functioning Scale were excluded from the analysis given that toddlers do not necessarily attend school or daycare and thus, depending on whether their child was enrolled in school or daycare, parent proxy respondents were given the option of completing the School Functioning items.

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). f