Table 3. Overall sensitivity and specificity of the observation-based classifier computed against the ADOS-G and ADOS-2 algorithm scores and best estimate clinical diagnosis.

	ADOS-G		ADOS-2		Clinical diagnosis
	Spectrum	Non-spectrum	Spectrum	Non-spectrum	Spectrum	Non-spectrum
OBC
Spectrum	2280	64	2304	40	766	3
Non-spectrum	53	219	69	203	23	15
Sensitivity	0.977		0.971		0.971
Specificity	0.774		0.835		0.833
Accuracy	0.955		0.958		0.968
PPV	0.973		0.983		0.996
NPV	0.805		0.746		0.395a

Abbreviations: ADOS-G, Autism Diagnostic Observation Schedule-Generic; NPV, negative predictive value; OBC, observation-based classifier; PPV, positive predictive value. Sensitivity was comparable across the three baselines for comparison; specificity was highest (>83%) when compared with ADOS-2 and best estimate clinical diagnosis.

^aBased on limited number of non-spectrum individuals.