Table 3. Multiple regression of well-being by sleep variables measured by actigraphy.

	Combined sample(N = 441)			Predominantly White subsample (n = 313)			African American subsample (n = 128)
	β	t	P	β	t	P	β	t	P
Positive Well-being
Satisfaction with Life Scale
Total Sleep Time (linear term)	−.08	−1.58	.115	−.10	−1.55	.122	−.02	−0.19	.852
Total Sleep Time (quadratic term)	.02	0.33	.739	.02	0.41	.680	−.01	−0.06	.955
Variability of Total Sleep Time	−.16	−3.01	.003	−.17	−2.63	.009	−.19	−1.83	.070
Wake After Sleep Onset	−.03	−0.65	.518	−.01	−0.13	.901	−.08	−0.85	.396
Sleep Onset Latency	−.02	−0.44	.658	.03	0.55	.583	−.08	−0.73	.465
Positive Affect
Total Sleep Time (linear term)	−.02	−0.30	.761	−.05	−0.69	.492	.07	0.68	.496
Total Sleep Time (quadratic term)	.05	1.07	.287	.01	0.22	.830	.13	1.17	.243
Variability of Total Sleep Time	−.12	−2.08	.038	−.12	−1.73	.084	−.18	−1.69	.094
Wake After Sleep Onset	−.05	−1.02	.308	.04	0.70	.486a	−.22	−2.24	.027a
Sleep Onset Latency	.00	−0.04	.966	.05	0.71	.481	.00	0.05	.962
Symptoms of Distress
General Distress Depressive Symptoms
Total Sleep Time (linear term)	.10	1.74	.083	.04	0.66	.511	.16	1.52	.132
Total Sleep Time (quadratic term)	.03	0.66	.511	−.02	−0.35	.725a	.22	2.02	.046a
Variability of Total Sleep Time	.19	3.39	<.001	.17	2.66	.008	.23	2.08	.039
Wake After Sleep Onset	−.02	−0.36	.716	−.06	−1.01	.314	.02	0.20	.841
Sleep Onset Latency	.03	0.45	.650	−.02	−0.24	.814	.04	0.39	.695
General Distress Anxious Symptoms
Total Sleep Time (linear term)	.14	2.43	.016	.07	1.17	.242	.20	1.87	.064
Total Sleep Time (quadratic term)	.00	0.08	.940	−.03	−0.47	.641	.09	0.82	.415
Variability of Total Sleep Time	.27	4.82	<.001	.27	4.27	<.001	.26	2.39	.019
Wake After Sleep Onset	−.02	−0.30	.767	.00	0.00	.999	−.04	−0.41	.685
Sleep Onset Latency	−.02	−0.40	.692	−.06	−1.01	.313	.01	0.08	.940
Loss of Interest
Total Sleep Time (linear term)	.13	2.25	.025	.09	1.35	.178	.17	1.64	.105
Total Sleep Time (quadratic term)	−.04	−0.87	.383	−.03	−0.42	.673	−.01	−0.04	.966
Variability of Total Sleep Time	.16	2.88	.004	.15	2.29	.023	.21	1.92	.057
Wake After Sleep Onset	.00	0.05	.962	−.05	−0.86	.390	.04	0.39	.699
Sleep Onset Latency	.05	0.81	.419	−.01	−0.11	.913	.06	0.54	.590
Anxious Arousal
Total Sleep Time (linear term)	.13	2.26	.024	.06	0.97	.331	.23	2.14	.034
Total Sleep Time (quadratic term)	.06	1.27	.206	.01	0.25	.805	.19	1.71	.090
Variability of Total Sleep Time	.19	3.43	<.001	.16	2.57	.011	.21	1.92	.057
Wake After Sleep Onset	.06	1.08	.283	.16	2.79	.006a	−.08	−0.78	.437a
Sleep Onset Latency	.04	0.75	.455	.07	1.12	.264	.05	0.50	.618

Note. Standardized regression coefficients are presented. Simultaneous entry of Total Sleep Time-linear term, variability of Total Sleep Time, Wake After Sleep Onset, and Sleep Onset Latency; Total Sleep Time-quadratic term was entered in separate models controlling Total Sleep Time-linear term, variability of Total Sleep Time, Wake After Sleep Onset, and Sleep Onset Latency. All analyses control age, gender, marital status, educational attainment, BMI, and twin status. Analyses of the combined sample additionally control sample membership (predominantly white American sample vs. urban African American sample).

Bonferroni-corrected significance level: P<.0083.

^acoefficients are significantly different (P<.05) in the predominantly white American sample and in the urban African American sample.