Table 4.

Multivariate Linear Regression Model with HbA1c as the Dependent Outcome.

	Unstandardised Coefficients		Standardised Coefficients	t	Sig.	Correlations
	B	Std. Error	Beta			Zero- order	Partial	Part
DEMOGRAPHIC FACTORS
Age (yrs)	.001	.001	.078	1.686	.092	.184	.058	.055
Sex (male=0, female=1)	−.011	.014	−.036	−.832	.405	−.113	−.029	−.027
Residence in USA (yrs)	.000	.001	.013	.328	.743	.072	.011	.011
Geographic site (IL=1, CA=2)	.030	.011	.095	2.844	.005	.070	.098	.092
College degree (no=0, yes=1)	−.018	.017	−.038	−1.074	.283	−.100	−.037	−.035
Income	−.013	.005	−.095	−2.509	.012	−.160	−.086	−.081
CLINICAL FACTORS
Body Mass Index (kg/m2)	−.002	.002	−.058	−1.011	.312	.143	−.035	−.033
Systolic bp (mmHg)	.001	.000	.091	1.938	.053	.182	.067	.063
Diastolic bp (mmHg)	−.001	.001	−.035	−.756	.450	.057	−.026	−.024
Smoke cigarettes (no=0, past=1, yes=2)	.016	.011	.050	1.424	.155	.085	.049	.046
Alcohol (1+ drinks/wk)	−.019	.012	−.056	−1.587	.113	−.023	−.055	−.051
Waist circumference (cm)	.002	.001	.162	2.806	.005	.227	.097	.091
BERLIN QUESTIONNAIRE RISK CATEGORIES
Category 1 (SDB): 2+ criteria met (items 1–5)	.022	.011	.071	2.059	.040	.122	.071	.067
Category 2 (EDS): 2+ criteria met (items 6–8)	−.005	.016	−.011	−.334	.738	.001	−.012	−.011
Category 3: HTN or BMI > 27.5 (kg/m2)	.034	.012	.108	2.704	.007	.210	.093	.088

Note: Dependent Variable: HbA1c (square-root transformation)

15 variables accounted for 12.5% of the variance in HbA1c (R² = .125; F_[15,850] = 7.9, p <.001).