Using the Negative Exponential Model to Describe Changes in Risk of Smoking-Related Diseases following Changes in Exposure to Tobacco

Table 2

Variation in by age^a for four smoking-related diseases as estimated in four recent publications.

Disease	Estimates of (95% CI)
	Age < 50	Age 50–59	Age 60–69	Age 70–79	^b
IHD [3]	1.47	5.22	7.48	13.77	<0.001
	(0.91–2.39)	(3.79–7.20)	(4.56–12.28)	(4.27–44.35)
Lung cancer [4]	6.98	10.39	10.60	12.99	<0.001
	(5.98–8.16)	(9.45–11.42)	(9.70–11.58)	(8.15–20.69)
COPD [5]	9.97	14.18	16.06	11.60	0.22
	(5.67–17.55)	(12.35–16.28)	(9.70–26.60)	(9.40–14.31)
Stroke [6]	1.98	3.47	7.71	17.74	0.34
	(0.41–9.65)	(0.79–15.19)	(2.12–27.97)	(1.46–215.7)

For prospective studies taken as age at baseline for IHD, COPD, and stroke but as age at midpoint of follow-up for lung cancer.
^bHeterogeneity between groups.