Improving screening methods for psychosis in an adolescent help-seeking population using the Child Behavior Checklist (CBCL) and the Youth Self Report (YSR) versus the Prodromal Questionnaire -16 items version (PQ-16)

Table 4 Screening values of a CAARMS classification yielded by Section A the various combinations of the measures and section B a sequential two step method

Cutoff scores reached on the measure(s)*	N reaching the cutoff n = 270	N and % reaching the cutoff total sample n = 1136	Sens	Spec	PPV	NPV	True positives	True negatives	False positives	False negatives
Section A: various combinations of measures
Did not reach any cutoff	26	191 16.8	–	–	–	–	–	–	–	–
↑PQ ↓CT ↓YT**	24	34 3.0	0.04	0.87	20.8	53.3	5	131	19	115
↓PQ ↓CT ↑YT	9	33 2.9	0.01	0.95	11.1	54.4	1	142	8	119
↓PQ ↑CT ↓YT	23	146 12.9	0.03	0.87	13.0	52.6	3	130	20	117
↑PQ ↓CT ↑YT	25	31 2.7	0.08	0.89	36.0	54.7	9	134	16	111
↑PQ ↑CT ↓YT	28	37 3.3	0.10	0.89	42.9	55.4	12	134	16	108
↓PQ ↑YT ↑CT	25	82 7.2	0.11	0.92	52.0	56.3	13	138	12	107
↑PQ ↑YT ↑CT	110	131 11.5	0.62	0.76	67.3	71.3	74	114	36	46
PQ and/or YT	221	449 39.5	0.95	0.29	51.6	87.8	114	43	107	6
PQ and/or CT	235	624 54.9	0.97	0.21	49.4	88.6	116	31	119	4
YT and/or CT	220	613 54.0	0.93	0.28	50.9	84.0	112	42	108	8
PQ and/or YT and/or CT	244	674 59.3	0.98	0.15	48.0	88.5	117	23	127	3
Section B: a sequential two step method
(1) ↑ CT (2) ↑ PQ	186 138	524 46.1 187 16.5	0.72	0.65	62.3	74.2	86	98	52	34
(1) ↑ YT (2) ↑ PQ	169 135	332 29.2 170 15.0	0.69	0.65	61.5	72.6	83	98	52	37
(1) ↑ CT and/or ↑ YT (2) ↑ PQ	220 163	613 54.0 226 19.9	0.79	0.55	58.3	76.6	95	82	68	25

^*Cutoff scores reached on the PQ-16 total score (PQ), CBCL Thought Problems total scale score (CT) and YSR Though Problems total scale score (YT)
^**↑ means ≥ cutoff ↓ means < cutoff
^***(1) and (2) represent a sequential method; in the first step a reached cutoff at CT or YT was selected and in the second step a reached cutoff at the PQ was selected

ISSN: 1753-2000