Table 4.

Coefficients from Poisson regression models and the relative excess risk due to interaction (RERI).

Characteristic	Panel A: Unadjusted			Panel B: Adjusted
	Main Effect	Interaction on Multiplicative Scale	Interaction on Additive Scale (RERI)	Main Effect	Interaction on Multiplicative Scale	Interaction on Additive Scale (RERI)
Male	0.459***	−0.003**	0.047***	0.492***	−0.004***	0.056***
Black	0.406***	−0.016***	0.019***	0.390***	−0.016***	0.022***
Low Education	0.431***	−0.013***	0.028***	0.424***	−0.011***	0.034***
Obese	0.145***	−0.007***	0.005***	0.119***	−0.005***	0.007***
Current Smoker	0.867***	−0.011***	0.107***	0.788***	−0.008***	0.109***

Note: Age measured in single years and centered at age 65 years. Main effects pertain to the coefficient at age 65. All models include main effect for age (not shown). The interaction on the relative scale is the coefficient for the product term of the risk factor with age. A negative value indicates a negative (i.e., sub-multiplicative) relationship. RERI tests for the presence and direction of interaction on the additive scale. A positive value indicates a super-additive interaction on the additive scale. Panel A are from models that only include the respective risk factor, age, and their interaction. Panel B includes adjustments for all socio-demographic characteristics (male, black, low education), time in study, and calendar year of exposure. Low education defined as having a HS degree or GED. Data from 1997-2009 National Health Interview Survey with deaths through 2011. ***p < .001; **p < .01.