. 2007 Dec 15;3(7):681–688.

Table 2.

Sleep and its Variability

Total Sleep Time (hrs)
Overall	7.89 (1.91)^a
by Gender
Men	7.72 (1.71)^a
Women	7.99 (2.02)
by Age
18–49	7.92 (1.87)^a
50–59	7.65 (2.19)
60–89	8.06 (1.68)
by BMI category
< 18.5	7.42 (3.60)^a
[18.5,25)	7.99 (1.74)
[25,30)	8.09 (1.77)
[30, 35)	7.48 (1.32)
[35, 40)	7.74 (1.84)
≥ 40	8.11 (2.79)
Total Sleep Time Quartiles
< 7	56 (28.1)^c
[7,8]	63 (31.7)
(8,9]	43 (21.6)
> 9	37 (18.6)
Regular Bed Time
Yes	132 (66.3)^c
No	67 (33.7)
Bed Time Range (hrs)^d	3.00 (2.00 – 4.00)^b
Regular Wake Time
Yes	163 (81.9)^c
No	36 (18.1)
Wake Time Range (hrs)^d	2.00 (2.00 – 4.25)^b
Nap
Yes	80 (40.2)^c
No	119 (59.8)
Nap Length if Yes (hrs)	1.00 (0.50 – 1.50)^b

Mean (SD)

Median (1st Q – 3rd Q)

n (%)

Patients were asked about differences in bed and wake times. If these times varied, a range of times was provided by the patient for the most recent week.