Table 4. Personalized operation conditioned on M-CHAT/F scores at 26 months.

NEG, negative; POS, positive.

M-CHAT/F outcome				Global performance (Truven)			Global performance (UCM)			Prevalence*
0–2 NEG	3–7 NEG	3–7 POS	≥8 POS	Specificity	Sensitivity	PPV	Specificity	Sensitivity	PPV
Specificity choices
0.2	0.54	0.83	0.98	0.95	0.585	0.209	0.95	0.505	0.186	0.022
0.21	0.53	0.83	0.98	0.95	0.586	0.208	0.95	0.506	0.184	0.022
0.42	0.87	0.98	0.99	0.98	0.433	0.331	0.98	0.347	0.284	0.022
0.48	0.87	0.97	0.99	0.98	0.432	0.331	0.98	0.355	0.289	0.022
0.38	0.54	0.94	0.98	0.95	0.736	0.203	0.95	0.628	0.178	0.017
0.3	0.55	0.94	0.98	0.95	0.737	0.203	0.95	0.633	0.179	0.017
0.58	0.96	0.98	0.99	0.98	0.492	0.302	0.98	0.373	0.247	0.017
0.59	0.96	0.98	0.99	0.98	0.491	0.303	0.98	0.372	0.248	0.017
0.46	0.92	0.97	0.99	0.977	0.534	0.291	0.977	0.448	0.256	0.017
0.48	0.92	0.97	0.99	0.978	0.533	0.292	0.978	0.448	0.257	0.017

*Prevalence reported by CDC is 1.7%, while the CHOP study reports a value of 2.23%. The results of our optimization depend on the prevalence estimate.