Table 3.

Stepwise Logistic Regression Analysis (Wald Method, Forward) to Predict Onset of BS Prior to APS in First-Episode Patients Showing Both Types of Symptoms

							95% CI for Exp(β)
Model (Mx)	Selected Variable	β	SE	Wald (df = 1)	P	Exp(β)	Lower	Upper
M1: BS ≥ APSa (n = 81); BS = APS equals positive event	Age at onset of illness (in y)	0.055	0.028	4.013	.045	1.057	1.001	1.116
	Level of educationb	0.960	0.323	8.821	.003	2.611	1.386	4.920
	Constant term	−2.224	0.915	5.906	.015	0.108
M2: BS > APSc (n = 52); BS = APS excluded	Level of education	0.999	0.385	6.747	.009	2.715	1.278	5.768
	First-degree relative with mental disorderd	−0.736	0.368	4.006	.045	0.479	0.233	0.985
	Constant term	−1.432	0.783	3.341	.068	0.239

Note: Entered variables—“age at onset of illness”; “level of education,” “first-degree relative with mental disorder,” “gender,” “diagnosis at discharge,” “duration of prodrome,” and the significant interactions “age at onset of illness × duration of prodrome,” “diagnosis at discharge × gender.” BS, basic symptoms; APS, attenuated psychotic symptoms; CI, confidence interval.

^aModel fit: χ² = 13 680, df = 2, P = .001 (40.0% right negative [10/25], 87.5% right positive [49/56] and altogether 72.8% right classifications [59/81]).

^bLow value equals low education.

^cModel fit: χ² = 11 438, df = 2, P = .003 (68.0% right negative [17/25], 74.1% right positive [−20/27], and altogether 71.2% right classifications [37/52]).

^dValues distributed as follows: 0 = none; 1 = psychosis; 2 = other mental disturbance.