Table 1

CareKoMS scale and items properties

Items	D	P (%)	Item-total correlation	KR-20*	Topic
Items included in the final scale
CareKoMS 4	0.24	46	0.25	0.76	Aetiopathogenesis
CareKoMS 5	0.35	29	0.21	0.75	Epidemiology
CareKoMS 7	0.44	81	0.38	0.73	Epidemiology
CareKoMS 10	0.56	42	0.32	0.74	Disease course
CareKoMS 11	0.57	46	0.36	0.73	Disease course
CareKoMS 12	0.54	68	0.37	0.73	Disease course
CareKoMS 13	0.56	48	0.31	0.74	Disease course
CareKoMS 14	0.46	66	0.33	0.74	Disease course
CareKoMS 15	0.43	70	0.29	0.74	Disease course
CareKoMS 16	0.48	78	0.38	0.73	Symptoms
CareKoMS 17	0.41	74	0.25	0.74	Symptoms
CareKoMS 19	0.52	75	0.41	0.73	Symptoms
CareKoMS 20	0.35	87	0.39	0.73	Symptoms
CareKoMS 25	0.54	62	0.34	0.73	Treatment
CareKoMS 26	0.20	90	0.20	0.74	Treatment
CareKoMS 27	0.43	68	0.26	0.74	Symptoms
CareKoMS 28	0.30	82	0.27	0.74	Symptoms
CareKoMS 29	0.33	86	0.34	0.74	Symptoms
CareKoMS 30	0.39	74	0.29	0.74	Treatment
CareKoMS 31	0.43	52	0.24	0.74	Symptoms
CareKoMS 32	0.44	48	0.24	0.74	Symptoms
Items removed from the final scale
CareKoMS 1	0.11	96	0.22	0.75	Aetiopathogenesis
CareKoMS 2	0.28	92	0.08	0.74	Aetiopathogenesis
CareKoMS 3	0.19	88	0.11	0.75	Aetiopathogenesis
CareKoMS 6	0.28	70	0.17	0.75	Epidemiology
CareKoMS 8	0.17	44	0.08	0.76	Diagnosis
CareKoMS 9	0.11	95	0.16	0.75	Diagnosis
CareKoMS 18	0.19	82	0.14	0.75	Symptoms
CareKoMS 21	0.07	90	0.06	0.75	Symptoms
CareKoMS 22	0.30	72	0.13	0.75	Treatment
CareKoMS 23	0.06	97	0.16	0.75	Treatment
CareKoMS 24	0.26	86	0.17	0.74	Treatment

*Corrected internal consistency calculated using Kuder-Richardson-20 coefficient obtained removing one item in turn.
CareKoMS, Caregivers’ Knowledge of Multiple Sclerosis; D, discrimination index; KR-20, Kuder-Richardson-20 coefficient; P, item difficulty.