Table 2.

Item location and centralised threshold values for the set of eight items with five response categories. Entire sample of students 11, 13 and 15 years old. The lower the item location value, the more severe symptom

Item		Location	Threshold 1	Threshold 2	Threshold 3	Threshold 4
It 1	Headache	0.023415	−0.786540	− 0.161090	0.130786	0.816848
It 2	Stomach-ache	−0.230490	− 0.749190	− 0.094010	−0.283000	1.126203
It 3	Backache	−0.140470	−0.023660	0.062261	−0.123770	0.085168
It 4	Feeling low	−0.085780	−0.732560	0.000632	0.059639	0.672292
It 5	Irritability or bad temper	0.482598	−1.376570	−0.376840	0.260856	1.492549
It 6	Feeling nervous	0.025897	−1.003510	− 0.264530	0.253783	1.014259
It 7	Difficulties in getting to sleep	0.271704	−0.242570	0.008973	0.143810	0.089783
It 8	Feeling dizzy	−0.346880	− 0.419110	0.244419	0.104895	0.069796

Disordered thresholds marked in italics