Table 1.

Descriptive statistics of the clinical variables and maximum error of estimate.

Clinical variables		Age		% Grade				ME
	n	M	SD	3rd	4th	5th	6th
Worthlessness	2,507	9.93	1.23	22.2	25.1	26.5	26.2	±1.88
Irritability	2,513	9.91	1.22	22.3	25.4	26.3	25.9	±1.88
Thinking problems	2,550	9.89	1.22	22.8	25.4	26.4	25.5	±1.86
Psychophysiological symptoms	2,413	9.91	1.23	22.4	25.1	26.4	26.2	±1.91

n = sample size; M = mean; SD = standard deviation; ME = maximum error of estimate (CL = 95%).