Table 2.

—Factor structure of the Idiopathic Hypersomnia Severity Scale in patients with idiopathic hypersomnia.

Questions	KMO Item by Item	In the Whole Sample (n = 226 patients)
		Communalities	Factors
			I	II	III
1	0.90	0.63	0.14	0.71	0.34
2	0.90	0.66	0.31	0.75	0.07
3	0.92	0.48	0.20	0.66	–0.003
4	0.92	0.58	0.39	0.65	0.07
5	0.86	0.32	0.43	0.37	–0.02
6	0.71	0.76	0.18	–0.10	0.85
7	0.86	0.68	0.09	0.37	0.73
8	0.90	0.52	0.24	0.68	–0.07
9	0.93	0.37	0.51	0.20	0.26
10	0.88	0.75	0.75	0.37	0.21
11	0.89	0.70	0.82	0.14	0.08
12	0.91	0.58	0.72	0.26	0.06
13	0.91	0.68	0.69	0.39	0.22
14	0.71	0.41	0.53	–0.34	0.08
Cronbach’s α	0.89	–	–	–	–
KMO measure of sampling adequacy	0.89	–	–	–	–
Percentage of cumulative variance explained	–	0.58

KMO = Kaiser-Meyer-Olkin index.