Table 2.

Correlations among sleep, cognitive status, and functional status variables.

	1	2	3	4	5	6	7	8
1. Sleep Efficiencya	1	0.79**	−0.31**	−0.03	−0.74**	−0.01	−0.17	0.10
2. TSTb		1	−0.13	0.11	−0.38**	−0.21*	−0.30**	0.32**
3. SOLc			1	−0.15	−0.08	0.17	0.12	−0.08
4. Awakenings				1	0.20	−0.25*	−0.14	0.17
5. WASOd					1	−0.16	−0.00	0.13
6. MMSEe						1	0.68**	−0.40**
7. LOAf							1	−0.30**
8. Gait Speedg								1

(N = 90)

^**Correlation is significant at the 0.01 level (2-tailed)

^*Correlation is significant at the 0.05 level (2-tailed)

Sleep Efficiency^a = ratio of time in bed to time asleep in minutes.

TST ^b = total sleep time in minutes per polysomnography.

SOL^c = minutes until onset of sleep.

WASO ^d = minutes of wake after sleep onset.

MMSE ^e = Mini Mental State Exam.

LOA ^f = Level of assistance required. Lower scores indicate more assistance required.

Gait Speed ^g = speed in seconds to walk six meters.