Table 3.

Exploratory factor analysis for PSQI.

PSQI Component	Factor 1 (Sleep Quality)	Factor 2 (Disturbances)
Habitual sleep efficiency	0.858
Sleep duration	0.811
Sleep latency	0.789
Subjective sleep quality	0.676
Daytime dysfunction		0.784
Sleep disturbances		0.695
Use of sleep medication		0.555
Variance explained (%)	36.6	23.0

Note: PSQI = Pittsburgh Sleep Quality Index. Principal components’ extraction and orthogonal varimax rotation.