Effects of phone versus mail survey methods on the measurement of health-related quality of life and emotional and behavioural problems in adolescents

Table 2 KINDL-R Test score distribution across modes of administration

	Mail		phone		Δ-methods
					All	Girls	Boys	8-12	13-18
	Mean	SD	Mean	SD	effect size "d" ^{stat. sign Δ-Mean; stat. sign Δ-SD}
Children's self-report	n = 891-895 ^a		n = 769-777 ^a		N = 1660-1672 ^a	N = 832-837 ^a	N = 824-832 ^a	N = 645-649 ^a	N = 1015-1026 ^a
Physical	75.70	16.20	75.87	15.99	0.01^ns,ns	-0.08^ns,ns	0.11^ns,ns	-0.02^ns,ns	0.07^ns,ns
Psychological	80.74	13.87	82.83	12.90	0.16**^,ns	0.15*^,ns	0.15*^,ns	0.13^ns,ns	0.19**^,
Self esteem	61.26	18.95	62.02	17.04	0.04^ns,**	-0.02^ns,ns	0.10^ns,ns	-0.12^ns,ns	0.15^,*
Family	82.82	14.92	83.79	16.13	0.06^ns,ns	-0.09^ns,**	0.22**^;ns	0.05^ns,ns	0.08^ns,*
Friends	76.50	16.34	79.50	13.71	0.20^,	0.22^,	0.16^,	0.15^ns,ns	0.25^,
School	68.31	17.99	71.36	17.67	0.17**^,ns	0.12^ns,ns	0.22**^,ns	0.23**^,ns	0.21**^,ns
Total Qol	74.23	11.01	75.88	9.90	0.16^,	0.06^ns,ns	0.25**^,ns	0.09^ns,ns	0.24**^,ns
Parent's proxy-report	n = 895-905 ^a		n = 759-791 ^a		N = 1654-1696 ^a	N = 822-842 ^a	N = 828-85 ^a	N = 661-66 ^a	N = 992-103 ^a
Physical	81.79	15.61	85.19	15.38	0.22**^,ns	0.17*^,ns	0.27**^,ns	0.17*^,ns	0.26**^;ns
Psychological	80.26	13.60	83.75	12.29	0.27^,	0.23**^,ns	0.30,	0.17*^,ns	0.33^;
Self esteem	66.62	15.05	71.49	14.83	0.19**^,ns	0.21**^,ns	0.17*^,ns	0.14^ns,ns	0.24**^;ns
Family	77.61	14.28	78.31	14.19	0.05^ns,ns	0.03^ns,ns	0.07^ns,ns	-0.02^ns,ns	0.09^ns,ns
Friends	77.16	14.62	77.66	14.07	0.03^ns,ns	0.08^ns,ns	-0.02^ns,ns	-0.05^ns,ns	0.09^ns,ns
School	73.41	16.22	76.18	15.64	0.17**^,ns	0.17*^,ns	0.18**^,ns	0.11^ns,ns	0.24**^,ns
Total Qol	76.46	10.47	78.81	9.69	0.23*^,	0.22**^,ns	0.24**^,ns	0.13^ns,ns	0.31**^,ns

^a Numbers vary due to missing values in the dimensions.
^b effect size classification: 0.20 = small; 0.50 = medium; 0.80 = large
^ns non significant; * p < .05; ** p < .01; first entry = t-test for mean differences; second entry = Levene test for SD-differences (all statistically significant SD-differences had the same direction as indicated by data-column 2 and 4)

ISSN: 1471-2458