Item Response Theory Analysis of Two Questionnaire Measures of Arthritis-Related Self-Efficacy Beliefs from Community-Based US Samples

Table 2

IRT parameters for the 9-item modified version of the 5-item Pain and 6-item Other Symptoms subscales from the Arthritis Self-efficacy scales (ASE).

Item	a	b1	b2	b3	b4	b5	b6	b7	b8	b9
1
2	2.09	−2.43	−1.91	−1.61	−1.32	−0.83	−0.40	−0.13	0.38	0.88
3	1.90	−1.91	−1.46	−1.16	−0.82	−0.43	−0.01	0.32	0.86	1.36
4	2.33	−2.20	−1.80	−1.33	−1.00	−0.54	−0.24	0.05	0.66	1.19
5
6	2.34	−1.93	−1.58	−1.22	−0.85	−0.36	0.01	0.30	0.69	1.21
7	2.81	−2.24	−1.77	−1.39	−1.29	−0.76	−0.45	−0.21	0.20	0.66
8	3.59	−2.02	−1.76	−1.37	−0.95	−0.48	−0.20	0.05	0.64	1.19
9	3.67	−2.13	−1.69	−1.27	−1.00	−0.58	−0.27	−0.01	0.45	0.97
10	5.10	−2.15	−1.71	−1.28	−1.09	−0.61	−0.33	−0.07	0.43	0.99
11	4.23	−2.10	−1.57	−1.23	−0.98	−0.54	−0.22	0.07	0.48	0.99