Table 3.

Estimates for the slope at each stage and AUC for the three embedded adaptive interventions.

	(No SGD, No SGD)			Estimate (95% CI) (No SGD, SGD)		(SGD, SGD)			Test of No Differenc in Slopes**
	Stage 1 Slope*	Stage 2 Slope	AUC	Stage 2 Slope	AUC	Stage 1 Slope	Stage 2 Slope	AUC	P-value
Natural Language Sample
TSCU	0.61 (−0.3,1.5)	0.06 (−0.5,0.6)	33.4 (25,42)	0.38 (−0.2,1.0)	36.0 (28,44)	2.56 (1.6,3.5)	−0.07 (−0.6,0.4)	51.8 (43,60)	<0.01
NDWR	0.60 (−0.05,1.2)	0.0 (−0.3,0.3)	21.7 (15.1,28.3)	0.20 (−0.2,0.6)	23.2 (16.6,29.9)	1.39 (0.7,2.1)	0.02 (−0.2,0.3)	29.8 (23.4,36.1)	0.12
Early Social Communication Scale
IJA	0 (−0.2,0.2)	0.06 (−0.1,0.2)	6.6 (5.0,8.2)	0.13 (0.001,0.26)	7.1 (5.5,8.7)	0.35 (0.03,0.7)	−0.02 (−0.2,0.1)	9.5 (7.3,11.7)	<0.05
IBR	0.19 (−0.1,0.5)	0.06 (−0.1,0.2)	16.1 (13.0,19.2)	0.11 (−0.1,0.3)	16.5 (13.2,19.8)	0.36 (0.1,0.6)	0.08 (−0.1,0.3)	18.0 (14.8,21.2)	0.31
Structured Play Assessment
UPA	0.17 (−0.1,0.4)	−0.04 (−0.18,0.1)	15.3 (13.2,17.5)	−0.03 (−0.2,0.1)	15.4 (13.2,17.5)	0.06 (−0.2,0.3)	0.1 (−0.03,0.2)	15.4 (13.1,17.5)	0.52

Notes.

Abbreviations: SGD—Speech generating device; TSCU—Total socially communicative utterances; NDWR— Number of direct word roots; IJA—Initiating joint attention; IBR—Initiating behavioral regulation; UPA—Unique play acts; AUC—the average area under the estimated longitudinal curve from baseline to week 36 (has the interpretation as the average outcome over the course of the study).

Slopes with a 95% confidence interval that does not include zero are boldfaced

^*The two adaptive interventions beginning with No SGD have identical stage. 1 slopes; hence, we only report it once under (No SGD, No SGD).

^**This is the hypothesis test that there is no difference in slopes between the three adaptive interventions, at any C stage; note that no difference in slopes implies that there is no difference in AUC