Table 5.

Internal Consistency of Pittsburgh Sleep Quality Index Factor Structure Models and Relationships (Spearman rho) with Actigraphy Measures (n = 71)

Factor structure models	ω (Cr α)	Time in bed (A)	Sleep onset (A)	Total sleep time (A)	Sleep efficiency (A)	WASO (A)	Number of wakes (A)
Single-factor model
PSQI (C 1–7)	0.705 (0.702)	0.027	0.203	−0.074	−0.307a	0.332b	0.171
PSQI (without C 6)	0.716 (0.712)	0.077	0.189	−0.028	−0.293a	0.319b	0.173
PSQI (C 1–6)	0.682 (0.677)	0.025	0.204	−0.071	−0.296a	0.323b	0.162
PSQI (C 1–5)	0.700 (0.697)	0.075	0.185	−0.023	−0.281a	0.310a	0.164
Two-factor model
Factor 1 (C 1, 2, 5, 6)	0.584 (0.573)	0.100	0.273a	0.031	−0.231	0.263a	0.167
Factor 2 (C 3, 4, 7)	0.624 (0.607)	−0.050	0.112	−0.155	−0.295a	0.305a	0.137
Three-factor model
Factor 1 (C 3, 4)	–(0.619)	−0.094	0.127	−0.213	−0.329b	0.337b	0.138
Factor 2 (C 1, 2, 6)	0.505 (0.498)	−0.025	0.258a	−0.057	−0.174	0.186	0.039
Factor 3 (C 5, 7)	–(0.396)	0.083	0.136	−0.005	−0.234	0.258a	0.191

^a p < 0.05.

^b p < 0.01.

A, actigraphy measure; C, PSQI component; Cr-α, Cronbach's alpha coefficient; ω, McDonald's omega with minimum of 3 items.