Table 4.
Sleep duration as a Mediator in the Race-Stroke Symptom Relationship using the ‘Difference of Coefficients Approach,’ in the Full and Normal BMI Samples.
| Sample | Model | β race | β* race | β*race - β* race | Bootstrap 95% CI | HR (95% CI)a |
|---|---|---|---|---|---|---|
| Full | Unadjusted | −0.13 | −0.10 | −0.03 | −0.09, 0.03 | 1.03 (0.97-1.09) |
| (n=5,666) | Model 4b | −0.05 | −0.03 | −0.02 | −0.08, 0.05 | 1.02 (0.95-1.08) |
| Model 5c | 0.11 | 0.13 | −0.03 | −0.12, 0.05 | 1.03 (0.95-1.13) | |
| Normal BMI | Unadjusted | 0.10 | 0.30 | −0.21 | −0.42, −0.02 | 1.23 (1.02-1.52) |
| (n=1,561) | Model 4b | 0.14 | 0.37 | −0.23 | −0.50, −0.03 | 1.26 (1.03-1.65) |
| Model 5c | 0.28 | 0.56 | −0.28 | −0.75, 0.01 | 1.33 (0.99-2.11) |
Hazard ratios greater than 1 indicate increased stroke symptom risk for blacks while accounting for sleep duration as a mediator.
Controlling for all variables in Models 1-4: Model 1=Demographics; Model 2=Stroke risk factors; Model 3=Psychological symptoms; Model 4=Health behaviors;
Controlling for all variables in Model 5=Model 4 + Diet Quality
Note. βrace = the regression estimate for race without sleep duration as a covariate; β* race = regression estimate for race when sleep duration was included as a covariate; βrace - β* race = difference in the regression estimates; CI=confidence interval; Bootstrap 95%CI = 95% confidence intervals obtained using percentile bootstrap with 1,000 samples; HR=hazard ratio; BMI=body mass index.