Validation of the Chinese EORTC chronic lymphocytic leukaemia module – application of classical test theory and item response theory

Table 6 Discrimination and difficulty parameters for QLQ-CLL17

	Discrimination	Threshold indices			S-χ²	P value
	a	b1	b2	b3	S-χ²	P value
SB
CLL1	1.265	−0.286	2.389	2.214	13.52	0.330
CLL2	3.112	−0.860	0.992	2.062	17.02	0.074
CLL3	3.166	−0.440	1.203	2.266	11.65	0.309
CLL4	0.880	−0.692	2.634	2.515	9.64	0.885
CLL5	1.279	−1.317	0.634	2.319	19.86	0.281
CLL6	0.761	−0.579	2.216	1.697	19.76	0.409
PC
CLL7	1.515	−0.290	1.979	2.340	16.52	0.050
CLL8	3.655	−1.226	0.797	1.727	6.16	0.291
CLL9	2.603	−0.624	1.174	2.465	3.77	0.438
CLL10	3.531	−0.699	1.053	1.866	2.18	0.704
WF
CLL11	3.702	−1.58	−0.121	0.557	10.53	0.65
CLL12	3.624	−1.667	−0.266	0.354	19.68	0.103
CLL13	3.568	−1.647	−0.152	0.526	12.62	0.478
CLL14	2.573	−1.143	0.098	0.395	10.86	0.900
CLL15	3.877	−1.707	−0.374	0.329	12.88	0.458
CLL16	0.776	−1.413	1.043	1.268	19.51	0.882
CLL17	1.022	−1.150	0.473	0.531	28.59	0.330

SB symptom burden, PC physical condition/fatigue, WF Worries/fears about health and functioning, a = discrimination, b = difficulty

ISSN: 1477-7525