Table 3.

Pearson correlation coefficients for sleep efficiency from polysomnography (PSG) and actigraphy devices^†

N = 30	PSG	Sleepwatch	Actiwatch	Actical
PSG		0.619**	0.651**	0.348
Sleepwatch	0.619**		0.653**	0.405*
Actiwatch	0.651**	0.653**		0.820**
Actical	0.348	0.405*	0.820**

^*p < 0.05;

^**p < 0.001;

^†Sleepwatch, Sleepwatch actigraph (Ambulatory Monitoring, Inc., Ardsley, NY); Actiwatch, Actiwatch actigraph (Respironics, Pittsburgh, PA); Actical, Actical actigraph (Respironics, Pittsburgh, PA)