Table 1.

Participant characteristics used for the analyses.

Study	Daily life (diary)	PSG sleep clinic	PSG healthy good sleepers
N	3752	28	22
Age (mean ± standard deviation in years)	69.1 ± 5.6	44.9 ± 14.9	22.8 ± 4.5
Sex	2822 males, 930 females	17 males and 11 females	7 males and 15 females
SPT-window duration (mean ± standard deviation)	7.7 ± 1.2 hours	8.4 ± 1.6 hours	6.7 ± 0.9 hours
Sleep onset time (mean in hh:mm ± standard deviation)	23:48 ± 71 minutes	22:32 ± 69 minutes	23:24 ± 54 minutes
Waking time (mean in hh:mm ± standard deviation)	7:28 ± 72 minutes	06:58 ± 76 minutes	06:09 ± 32 minutes