Table 4.

Multiplicative effect^a of a 1 point greater Pathobiological Determinants of Atherosclerosis in Youth (PDAY) risk score due to the modifiable risk factors measured in 1986 on carotid artery intima-media thickness (IMT) and a 1 point increase in risk score due to the modifiable risk factors between 1986 and 2001; and odds ratios for same points for predicting carotid artery intima-media thickness >90^th percentile or a plaque. The model includes sex and age in 2001.

Risk score due to modifiable risk factors	Carotid artery IMT		IMT >90th percentile or a plaque
	Multiplicative effecta (95% CI)	R2	Odds ratio (95% CI)	c-statisticb
One point increase in 1986 PDAY risk score	1.008 (1.005-1.012)	0.097	1.118 (1.048-1.194)	0.674
One point increasec in risk score between 1986 and 2001	1.003 (1.001-1.006)		1.004 (0.994-1.097)

^aThe value of Y (that is, carotid artery IMT) for predictor variable with value X+1, labeled Y_X+1, is equal to the multiplicative effect e^β (the anti-log of the regression coefficient) multiplied by the Y value at X, that is, Y_X+1= e^βY_X.

^bThe c-index is the proportion of all pairs of subjects, one with and one without lesions (>90^th percentile or plaque), in which the subject with the lesions has the higher risk score.²¹

^cThe reciprocal of the multiplicative effect or odds ratio describes the effect of a decrease in the risk score by 1 point between 1986 and 2001