. 2015 Sep 7;7:166. doi: 10.3389/fnagi.2015.00166

Table 2.

Bivariate correlations between sleep indices and covariates.

	Gender (female)^a	Education^a	Age	MoCA	Days of wear
1. MW-latency	−0.07	−0.19	0.01	−0.05	−0.03
2. MW-efficiency	0.02	−0.15	0.07	0.06	0.11
3. MW-duration	0.05	−0.27^*	0.01	0.08	0.07
4. MW-fragmentation	−0.19	0.08	0.26^*	−0.22	−0.10
5. MW-composite	0.11	−0.15	−0.10	0.15	0.10
6. L5 Start	0.05	0.06	−0.03	0.03	−0.06
7. M10 Start	0.30^**	0.09	−0.20	0.22^*	−0.03
8. Relative amplitude	−0.03	−0.16	−0.17	0.27^*	0.21
9. Inter-daily stability	−0.12	0.01	0.09	0.01	0.04
10. Intra-daily variability	−0.12	−0.06	0.16	−0.15	−0.07
11. PSQI-latency	0.23	0.13	−0.19	−0.07	−0.13
12. PSQI-efficiency	0.04	0.10	−0.18	−0.05	0.05
13. PSQI-duration	−0.06	−0.02	−0.17	0.01	0.01
14. PSQI-disturbances	0.21	−0.21	−0.07	0.01	−0.06
15. PSQI-sleep quality	0.17	−0.08	−0.07	0.07	−0.05
16. PSQI-total	0.17	−0.09	0.001	0.12	−0.10
17. SD-latency	0.31^**	−0.07	−0.26^*	0.24^*	−0.04
18. SD-accuracy	0.15	−0.18	−0.19	0.09	0.03
19. SD-awakenings	0.08	0.17	−0.23^*	−0.01	−0.02
20. SD-quality	−0.01	0.08	−0.004	−0.02	0.17
21. SD-sleep window	−0.14	−0.19	−0.03	−0.08	0.12
22. SD-sleep duration	−0.17	−0.05	−0.02	−0.21	0.12

Non-parametric Spearman's rho (ρ). MMSE, Mini-Mental State Examination; MoCA, Montreal Cognitive Assessment; MW, motion watch; PSQI, Pittsburgh Sleep Quality Index; SD, sleep diary.

p < 0.05;

^**

p < 0.01.