TABLE 2.

Comparison of M-CHAT Scores According to Level of Study Participation

Variable	N	Mean (95% CI)	t Test, P	TOST
				t1 P	t2 P
Overalla			<.001	<.001	>.99
M-CHAT fail	341	5.0 (4.7–5.3)
M-CHAT pass	4730	0.4 (0.4–0.4)
M-CHAT failb			.78	.003	<.001
Without M-CHAT/F	144	5.0 (4.5–5.5)
With M-CHAT/F	197	5.0 (4.6–5.4)
M-CHAT/F completeda			.03	<.001	.40
Not in study	98	4.5 (4.0–5.0)
In study	99	5.4 (4.8–6.0)
M-CHAT/F failc			.67	.26	.07
Not in study	21	8.1 (6.5–8.7)
In study	40	7.7 (6.6–8.8)
M-CHAT/F passb			.17	<.001	.002
Not in study	77	3.5 (3.3–3.7)
In study	59	3.8 (3.4–4.3)

Comparisons were made with 2-tailed t test and TOST, Δ = 1 point. CI, confidence interval.

^aRelevant difference.

^bEquivalence.

^cIndeterminate (underpowered).