Table 4.

Transformation of raw score to Rasch-based scores.

Raw scores	θ	Rasch interval scale (0–4)	Z	%	T
0	−3.90	0.00	−2.27	1	27
1	−3.11	0.41	−1.81	4	32
2	−2.57	0.69	−1.49	7	35
3	−2.21	0.88	−1.28	10	37
4	−1.93	1.03	−1.11	13	39
5	−1.69	1.15	−0.97	17	40
6	−1.49	1.25	−0.86	20	41
7	−1.31	1.35	−0.75	23	43
8	−1.15	1.43	−0.66	26	43
9	−1.00	1.51	−0.57	29	44
10	−0.86	1.58	−0.49	31	45
11	−0.73	1.65	−0.41	34	46
12	−0.60	1.72	−0.33	37	47
13	−0.48	1.78	−0.26	40	47
14	−0.36	1.84	−0.19	42	48
15	−0.25	1.90	−0.13	45	49
16	−0.13	1.96	−0.06	48	49
17	−0.02	2.02	0.01	50	50
18	0.09	2.08	0.07	53	51
19	0.21	2.14	0.14	56	51
20	0.32	2.20	0.21	58	52
21	0.44	2.26	0.28	61	53
22	0.56	2.32	0.35	64	53
23	0.68	2.38	0.42	66	54
24	0.81	2.45	0.50	69	55
25	0.94	2.52	0.57	72	56
26	1.09	2.59	0.66	75	57
27	1.24	2.67	0.75	77	57
28	1.41	2.76	0.85	80	58
29	1.61	2.87	0.97	83	60
30	1.83	2.98	1.10	86	61
31	2.11	3.13	1.26	90	63
32	2.47	3.31	1.47	93	65
33	3.00	3.59	1.78	96	68
≥34	3.79	4.00	2.25	99	72

θ, estimated Pearson’s latent trait score for depression; %, percentiles; Z (M = 0, SD = 1); T (M = 50, SD = 10).