Birth weight in a large series of triplets

BMC Pediatrics

Table 5 Model fitting results of the means model on triplet BW

step	Model	N_parameters	-2LL	df	to model	Χ ²	Δ df	p
1	Full model	25	576.10	1194
2	a. Equal mean MZ pairs within MZ and DZ trios	22	577.11	1197	1	1.01	3	0.80
	b. Equal var MZ pairs within MZ and DZ trios	21	579.62	1198	2a	2.51	1	0.11
	c. Equal cov MZ pairs within MZ and DZ trios	20	581.32	1199	2b	1.70	1	0.19
3	a. Equal mean DZ/TZ	17	597.89	1202	2c	16.57	3	'0.00
	b. Equal var DZ/TZ	19	584.16	1200	2c	2.84	1	0.09
	c. Equal cov DZ/TZ	18	585.71	1201	3b	1.01	2	0.31
4	a. Equal mean within MZ	16	591.32	1203	3c	5.61	2	0.06
	b. Equal mean within DZ	14	592.24	1205	4a	0.92	2	0.63
	c. Equal mean within TZ	12	621.31	1207	4b	29.07	2	0.00
5	a. Effect GA² = 0	13	594.73	1206	4b	2.49	1	0.11
	b. Effect GA = 0	12	1013.26	1207	5a	418.53	1	0.00
	c. Effect sex = 0	12	631.42	1207	5a	36.69	1	0.00
	d. Effect alcohol = 0	12	594.84	1207	5a	0.11	1	0.74
	e. Effect smoking = 0	11	605.74	1208	5d	10.9	1	0.00

MZ = monozygotic; DZ = dizygotic; TZ = trizygotic; GA = gestational age. The best fitting model is printed in bold font.

ISSN: 1471-2431