Table 2.

SHHS Mean Total Sleep Time in Minutes^£

	Habitual HABTST			AM Estimated AMTST			Polysomnogram PSGTST
	Mean	SD	N	Mean	SD	N	Mean	SD	N
Gender
Male	424	74	980	379	84	970	355	57	993
Female	421	74	1,103	381	86	1,092	371‡	62	1,120
Ethnicity
Caucasian	424	70	1,562	376	83	1,544	365	57	1,588
Others	415†	87	521	392†	90	518	359	68	525
Age category
≤67 years	424	70	1,099	384	80	1,095	373	58	1,114
>67 years	421	79	983	375†	90	966	354‡	61	997
BMI
Nonobese (<30%)	423	73	1,279	378	85	1,261	367	59	1,298
Obese (>=30%)	421	77	779	382	85	775	358‡	62	788
Education
<12 years	432	95	266	397	102	260	350	67	268
12–16 years	420	73	1,147	375	84	1,133	363	60	1,162
>16 years	428*	61	493	385*	78	491	369*	55	502
Time Zone
Pacific/Eastern	416	78	1,045	370	87	1,021	361	60	1,057
Mountain/Central	429‡	70	1,038	389‡	82	1,041	366	60	1,055
RDI4%
<5	416	70	571	381	82	566	372	56	579
5-<15	424	76	812	380	86	801	366	62	824
15-<30	420	70	410	377	82	406	354	58	417
>=30	430	79	266	377	90	265	355§	60	269
Chronic Lung Disease
No	424	74	1,826	380	84	1,805	365	58	1,853
Yes	414	77	257	376	91	257	358	62	260
Chronic Heart Disease
No	424	71	1,649	382	82	1,637	368	58	1,673
Yes	418	85	429	373	96	420	348‡	65	434
Any Alcohol
No	422	75	1,916	380	85	1,904	364	61	1,941
Yes	422	66	145	381	83	147	367	52	148
Any Caffeine
No	422	73	1,704	377	86	1,696	365	59	1,728
Yes	423	82	357	393†	80	354	360	64	361

^£t-test was used to compare means between the two groups in gender, age category, ethnicity, BMI, time zone, any chronic lung or heart disease, and any alcohol or caffeine intake in each of the three sleep assessments. Comparisons between the three categories in education and RDI4% were made using one-way analysis of variance (ANOVA) in each of the three sleep assessments.

^†p-value <0.05 for t-test.

^‡p-value <0.0001 for t-test.

^*p-values <0.001 for one-way analysis of variance (ANOVA).

^§p-value <0.0001 for ANOVA.