Table 3.

Risk of Incident PAD According to Pack Years of Smoking

	Smoking Exposure Status
N=39227	0	< 10 pack years	10 to < 30 pack years	≥ 30 pack years	P-trend*
Events / Person-years of follow-up	30 / 260855	28 / 110538	67 / 94648	49 / 33887	-
Age-adjusted incidence rate†	0.12	0.28	0.72	1.33	-
Age adjusted model (n=39227)	1.0 (Referent)	2.30 (1.38–3.86)	6.43 (4.18–9.89)	11.06 (7.01–17.43)	<0.001
Multivariable model 1 (n=39803)‡	1.0 (Referent)	2.33 (1.39–3.90)	6.54 (4.25–10.06)	10.76 (6.82–16.97)	<0.001
Multivariable model 2 (n=38960) §	1.0 (Referent)	2.52 (1.49–4.25)	6.75 (4.33–10.52)	11.09 (6.94–17.72)	<0.001

Data are HR (95% CI)

^*P for trend across categories of cigarette exposure

^†Incidence rates are per 1000 person-years of observation

^‡Additionally adjusted for history of hypertension, history of diabetes, and history of hypercholesterolemia

^§Additionally adjusted for body mass index, alcohol consumption, and physical activity

PAD = Peripheral artery disease