. Author manuscript; available in PMC: 2017 Mar 1.

Published in final edited form as: Sleep Breath. 2016 Jan 25;20(1):293–301. doi: 10.1007/s11325-016-1313-4

Table 3.

The factor loadings in exploratory factor analysis of the Pittsburgh Sleep Quality Index (PSQI) among pregnant women (N=1,488)

Components	Factor loadings
Components	Factor 1	Factor 2
1. Sleep duration	0.87	−0.08
2. Sleep disturbance	0.04	0.72
3. Sleep latency	0.47	0.30
4. Daytime dysfunction due to sleepiness	−0.14	0.80
5. Sleep efficiency	0.88	−0.04
6. Subjective sleep quality	0.47	0.49
7. Sleep medication use	0.13	0.31

Exploratory factor analysis was conducted using the principal component analysis with promax rotation