Table 5.

Binary Mediation Coefficients for Accelerated aging at Y₂₀ (2005–2006) Mediating the Relationship between Social Factors at Y₁₅ (2000–2001) and All-cause Mortality (2007–2018): CARDIA, 2000–2018.

	Depression Score (Points, Continuous) (95% CI)		Social Participation (Number of groups, Continuous) (95% CI)		Socioeconomic Status Score (Points, Continuous) (95% CI)
Binary Mediation Resultsa	Unadjusted	Adjustedb	Unadjusted	Adjusted	Unadjusted	Adjusted
Path a	0.12 (0.09, 0.16)	0.03 (-0.001, 0.07)	-0.04 (-0.08, -0.01)	-0.03 (-0.06, 0.003)	-0.26 (-0.30, -0.22)	-0.09 (-0.13, -0.06)
Path b	0.23 (0.10, 0.37)	0.27 (0.12, 0.42)	0.24 (0.11, 0.37)	0.27 (0.11, 0.42)	0.19 (0.05, 0.33)	0.24 (0.09, 0.40)
a*b (indirect effect of X on Y)	0.02 (0.01, 0.05)	0.01 (0.002, 0.03)	-0.01 (-0.02, -0.003)	-0.01 (-0.001, -0.02)	-0.04 (-0.09, 0.01)	-0.02 (-0.04, -0.01)
Total Effect of X on Y	0.23 (0.12, 0.32)	0.21 (0.07, 0.31)	-0.21 -0.07, -0.38)	-0.19 (-0.05, -0.36)	-0.29 (-0.38, -0.16)	-0.26 (-0.40, -0.11)
Percent total effect mediated (% indirect of total effect)	12.45%	4.39%	5.10%%	4.31%	13.42%	9.07%

The coefficient for Path a corresponds to the association between the independent variable and the mediator; the coefficient for path b corresponds to the association between the mediator and the outcome; a*b corresponds to the effect of the mediation. 95% CI of a*b is bias-corrected and tests whether different than zero; The total effect of X on Y reports the indirect and direct effect of the independent variable on the outcome; percent total effect mediated is the percentage of the outcome that can be attributed to the mediator.

^bAdjusted for sex, chronological age, race, site, smoking status, and mL alcohol per week.

^aPath a = pathway from independent variable (depression score or racial discrimination) to mediator (accelerated aging); Path b = pathway from mediator (accelerated aging) to outcome (stroke).