. Author manuscript; available in PMC: 2018 Oct 1.

Published in final edited form as: J Autism Dev Disord. 2017 Oct;47(10):3296–3310. doi: 10.1007/s10803-017-3231-0

Table 4.

Comparison of Positive Predictive Value, Sensitivity & Specificity Between Younger and Older Age Groups (Criterion: ASD/Developmental Delay Diagnosis)

			95% Confidence		Difference		Equivalence
	PPV	SE	Interval		Z	p	Z₁	p₁	Z₂	p₂

*M-CHAT PPV*

< 20 Months	0.65	0.07	0.51	0.78	−0.79	.430	1.85	.032	0.27	.392

20+ Months	0.72	0.06	0.60	0.84

*M-CHAT/F PPV*

< 20 Months	0.71	0.07	0.59	0.84	−3.34	<.001	4.69	<.001	−1.99	.977

20+ Months	0.96	0.03	0.91	1.01

*M-CHAT/F Sensitivity*

< 20 Months	0.32	0.07	0.19	0.45	−3.68	<.001	4.67	<.001	−2.69	.996

20+ Months	0.69	0.07	0.57	0.82

*M-CHAT/F Specificity*

< 20 Months	0.76	0.06	0.64	0.88	−2.26	.024	3.64	<.001	−0.88	.811

20+ Months	0.93	0.04	0.86	1.00

*M-CHAT/F False Discovery Rate*

< 20 Months	0.29	0.07	0.16	0.41	3.34	<.001	−1.99	.977	4.69	<.001

20+ Months	0.04	0.03	0.00	0.09

Difference
Equivalence	<20 Months n=48
Indeterminate	20+ Months n=50