Psychophysiological Associations between Chronic Tinnitus and Sleep: A Cross Validation of Tinnitus and Insomnia Questionnaires

Table 3

Factor solutions for the sleep components using principal component analyses (PCAs).

	PCA with all TQ and RIS items	PCA with only TQ sleep and RIS items			PCA with only RIS items
	Factor 1	Factor 1	Factor 2	Factor 3	Factor 1	Factor 2
	Sleep	Sleep depth	Tinnitus-related sleep	Fearful focusing and sleep onset	Sleep depth	Fearful focusing
RIS items
1	(0.357)			0.570		(0.434)
2	0.693	0.491			0.667
3	0.705	0.686			0.799
4	0.688	0.604			0.610
5	0.628	0.556			0.553
6	0.696	0.666			0.595
7	0.606			0.507		0.638
8	0.542			0.531		0.774
9
10
TQ items
4	0.531		0.768
12	0.538		0.771
31	0.582		0.537
36	(0.389)		0.594

Values in brackets lie below the a priori defined factor loading threshold of 0.45.