Table 3.

Model error for the prediction of the 1–7-year GH growth response expressed in Dheight SD scores for the model group and the validation group separately: for the total group and subdivided into children born AGA or SGA.

Model group				Validation group
Total group:	n	SDres	SDstudRes	Total group:	n	SDres	SDstudRes
1–2 year	162	0.17	1.00	1–2 year	205	0.19	1.11
1–3 years	97	0.29	1.00	1–3 years	111	0.28	0.97
1–4 years	53	0.38	1.00	1–4 years	58	0.35	0.90
1–5 years	34	0.43	1.00	1–5 years	40	0.45	1.04
1–6 years	17	0.48	1.00	1–6 years	29	0.40	0.84
1–7 years	7	0.57	1.00	1–7 years	9	0.43	0.75
AGA:				AGA:
1–2 year	125	0.17	0.99	1–2 year	117	0.19	1.12
1–3 years	69	0.28	0.96	1–3 years	63	0.26	0.90
1–4 years	39	0.39	1.02	1–4 years	31	0.31	0.82
1–5 years	21	0.44	1.03	1–5 years	18	0.39	0.92
1–6 years	8	0.45	0.95	1–6 years	15	0.42	0.88
1–7 years	7	0.57	1.00	1–7 years	3	0.26	0.45
SGA:				SGA:
1–2 year	37	0.18	1.05	1–2 year	88	0.19	1.09
1–3 years	28	0.31	1.08	1–3 years	48	0.30	1.05
1–4 years	14	0.36	0.93	1–4 years	27	0.37	0.98
1–5 years	13	0.41	0.96	1–5 years	22	0.49	1.13
1–6 years	9	0.50	1.04	1–6 years	14	0.37	0.79
1–7 years	0	-	-	1–7 years	6	0.49	0.87

SDres = root mean square error of the residuals.

SD stud Res = SDres/SDresModelgroup

For a reliable model, the SD_res should be similar, or lower, for the validation group compared with the SD_res from the model group.