Table 3.

Optimal IGA × BSA cutoffs for predictability of PASI score ≤1 or BSA <3% MDA definition (pooled secukinumab 300 mg treatment group)

Week	IGA × BSA	Sensitivity	Specificity	Youdenindexa
2	3.50	0.9985	1.0000	0.99850
3	4.50	0.9849	1.0000	0.98487
4	5.20	0.9637	0.9583	0.92203
8	2.99	0.9906	0.8972	0.88782
12	2.98	0.9897	0.9167	0.90636
13	3.00	0.9851	0.9419	0.92701
14	3.10	0.9677	0.9269	0.89464
15	3.00	0.9832	0.9511	0.93439
16	3.00	0.9750	0.9551	0.93015
20	3.00	0.9937	0.9503	0.94393
24	2.80	0.9928	0.9470	0.93978
28	2.80	1.0000	0.9360	0.93596
32	2.65	1.0000	0.9521	0.95214
36	3.00	1.0000	0.9645	0.96447
40	3.00	0.9915	0.9617	0.95326
44	3.00	0.9836	0.9485	0.93206
48	3.00	1.0000	0.9490	0.94898
52	3.00	1.0000	0.9631	0.96306

BSA, body surface area; IGA, 5-point Investigator's Global Assessment; MDA, minimal disease activity; PASI, Psoriasis Area and Severity Index.

^aYouden index = sensitivity + specificity − 1.