Table 3. Intercept (c) parameters for the graded MIRT model used in calibrated projection of PAIS scores from responses to the PedsQL™ asthma symptoms scale; the items are sorted within scale by the parameter b, an index of severity.

Item		c1	c2	c3	c4	b
PAIS—17 items
14	I coughed because of my asthma	3.48	1.33	−1.76	−3.99	0.09
6	My chest felt tight because of my asthma	1.95	0.78	−1.37	−2.76	0.18
8	I had trouble breathing because of my asthma	2.44	0.87	−2.42	−4.37	0.30
4	My body felt bad when I was out of breath	1.66	0.51	−1.58	−2.86	0.31
9	My asthma bothered me	2.30	0.71	−2.25	−4.00	0.31
5	I felt scared that I might have trouble breathing because of my asthma	1.45	0.18	−2.03	−3.59	0.52
15	It was hard to take a deep breath because of my asthma	1.96	−0.19	−3.46	−5.65	0.53
1	I got tired easily because of my asthma	1.34	0.25	−1.57	−2.98	0.54
12	I felt wheezy because of my asthma	2.17	−0.21	−4.30	−7.23	0.62
10	It was hard for me to play sports or exercise because of my asthma	0.92	−0.16	−2.31	−3.58	0.63
3	I was bothered by the amount of time I spent wheezing	0.87	−0.28	−2.22	−3.54	0.73
11	I had trouble sleeping at night because of my asthma	0.13	−1.43	−3.74	−5.36	0.93
2	My asthma bothered me when I was with my friends	0.20	−0.81	−2.87	−4.44	1.29
13	I had asthma attacks	−1.51	−3.88	−7.57	−10.26	1.49
17	I missed school because of asthma	−0.56	−1.31	−2.97	−3.94	1.49
16	I had trouble walking because of my asthma	−1.19	−2.27	−3.71	−5.32	1.60
7	It was hard for me to play with pets because of my asthma	−1.47	−3.73	−6.60	−8.75	1.72
PedsQL asthma symptoms scale—11 items
23	I cough	4.44	2.17	−1.70	−4.08	−0.08
25	I have a stuffy or runny nose	1.64	0.55	−1.29	−2.29	0.32
22	I get out of breath	2.05	0.69	−2.14	−3.82	0.36
24	It is hard to take a deep breath	1.79	−0.65	−4.59	−7.02	0.77
19	I feel wheezy	1.50	−1.05	−5.83	−8.24	0.87
18	My chest hurts or feels tight	0.77	−0.56	−3.19	−5.50	0.92
26	I wake up at night with trouble breathing	−0.17	−1.88	−4.11	−5.82	0.96
28	It is hard for me to play outside	0.14	−1.18	−3.44	−5.02	1.08
21	I get scared when I have asthma attacks	−0.48	−1.20	−2.84	−3.68	1.21
27	It is hard for me to play with pets	−1.91	−4.02	−7.34	−9.21	1.67
20	I have asthma attacks	−2.04	−4.89	−9.10	−12.15	1.72