. Author manuscript; available in PMC: 2014 Dec 1.

Published in final edited form as: J Speech Lang Hear Res. 2014 Jun 1;57(3):850–864. doi: 10.1044/2013_JSLHR-L-12-0240

Table 2. Outcome at 12 years of classification of LI at 4 years.

Classification	Twins at 4 years		Language score at 12 years		% of LI twins at 4 who are LI at 12 (F; M)	% of twins LI at 4 years below mean at 12, but not LI	Likelihood ratio (LR+) for delay at 12 years
Classification	N	%	M	SD	% of LI twins at 4 who are LI at 12 (F; M)	% of twins LI at 4 years below mean at 12, but not LI	Likelihood ratio (LR+) for delay at 12 years
Full sample	2,922	100.0	0.01	0.99	12.4 (12.4; 12.3)	32.5	1.0
Psychometric LI	237	8.1	−0.44	1.08	24.5 (25.2; 23.6)	37.1	2.3
Parent referral	171	5.9	−0.06	0.97	11.1 (11.5; 10.8)	38.0	0.9
Both psychometric LI and parent referral	110	3.8	−0.65	1.06	29.1 (27.3; 29.9)	40.0	3.0
Neither	2,404	82.3	0.09	0.96	10.5 (10.9; 9.9)	31.3	0.8

Note. Language score at 12 = age-regressed composite score from the four receptive language measures.