Table 5.

Mixed-effects Linear Regression Model of Total Sleep Time in Minutes by Type of Assessment (Habitual, AM Estimated, and PSG) and Other Predictive Variables

Variables	Regression coefficient	p-value	95% CI*
Habitual	61.0	<0.0001	57.0 – 65.0
AM Estimated	17.7	<0.0001	13.7 – 21.8
BMI, obese	−5.2	0.041	−10.2 – −0.22
12–16 yr of education	−7.5	0.049	−15.0 – −0.02
>16 yr of education	−1.1	0.80†	−9.9 – 7.7
Mountain/Central time zone	14.9	0.010	3.5 – 26.3
Any Heart Disease	−9.8	0.001	−15.7 – −3.92
Intercept	363.9	<0.0001	353.3 – 374.5

^*CI = confidence interval. Note: PSG is the reference category for type of assessment, non-obese is the reference category for BMI, <12 years of education is the reference category for education, and Pacific/Eastern is the reference category for time-zone, no heart disease is the reference category for any heart disease.

^†p-value < 0.01, difference for linear contrast of coefficients between 12–16 and >16 years of education.