Table 2.

Comparison of Sleep Parameters Assessed by PSG and Actigraphy (x̄ ± SD): 5 Immobile or Mobile Minutes Required for Sleep Onset or End (n = 50)

Parameters	PSG	Actigraphy	Difference	P value
TST (min)	267.5 ± 71.4
0		178.8 ± 81.7	−88.7	< 0.001
5		265.6 ± 71.4	−1.9	0.818
10		289.1 ± 67.8	21.6	0.009
20		312.7 ± 64.0	45.2	< 0.001
40		333.4 ± 59.5	65.9	< 0.001
SE (%)	65.6 ± 16.9
0		43.8 ± 19.7	−21.8	< 0.001
5		65.1 ± 16.9	−0.5	0.797
10		70.8 ± 15.7	5.2	0.009
20		76.6 ± 14.3	11.0	< 0.001
40		81.7 ± 12.9	16.1	< 0.001
WASO (min)	96.6 ± 59.2
0		207.2 ± 73.0	110.6	< 0.001
5		120.4 ± 54.0	23.7	< 0.001
10		96.9 ± 47.2	0.3	0.975
20		73.3 ± 38.9	−23.3	0.004
40		52.5 ± 31.2	−44.1	< 0.001

Parameters in italic: various actigraphy thresholds. Values in bold are closest to PSG values. TST: total sleep time; SE: sleep efficiency; WASO: wake after sleep onset.