Table 5.

Synergistic Interaction Between Smoking, Diabetes, and Family History of Pancreatic Cancer (FHPC) Among Women

Interaction Variables		Men AOR (95% CI)*	P	Women AOR (95% CI)*	P
Smoking	Diabetes
No	No		1 (reference)
Yes	No	1.4 (1.1–1.9)	0.04	2.4 (1.7–3.4)	0.0001
No	Yes	2.6 (1.3–5.2)	0.006	4.2 (1.7–10.4)	0.002
Yes	Yes	2.6 (1.6–4.4)	0.0001	6.4 (2.3–17.5)	0.0001
Heavy smoking	Diabetes
Yes	No	1.5 (1.1–2.2)	0.03	3.6 (2.2–5.7)	0.0001
No	Yes	2.6 (1.3–5.3)	0.008	4.1 (1.7–10.3)	0.002
Yes	Yes	3.6 (1.8–7.2)	0.0001	9.3 (2.0–44.1)	0.005
Smoking	FHPC
No	No		1 (reference)
Yes	No	1.4 (1.1–1.9)	0.01	2.2 (1.6–3.1)	0.0001
No	Yes	4.6 (1.9–10.9)	0.001	2.7 (1.1–6.7)	0.03
Yes	Yes	2.4 (1.1–5.4)	0.04	10.1 (2.2–45.9)	0.003
Heavy smoking	FHPC
Yes	No	1.6 (1.1–2.2)	0.008	3.4 (2.1 –5.4)	0.0001
No	Yes	4.7 (1.9–11.1)	0.001	2.9 (1.2–7.5)	0.02
Yes	Yes	2.2 (0.7–6.2)	0.1	12.8 (1.6–108.9)	0.02

^*AOR = odds ratio adjusted for age, sex, race/ethnicity, history of diabetes, family history of cancer, heavy alcohol consumption, education level, and state of residency.

^†S = synergy index described by Rothman (38) = (OR₁₁ − 1)/(OR₀₁ + OR₁₀ − 2), where OR₁₁ = odds ratio of the joint effect of two risk factors and OR₀₁ and OR₁₀ = OR of each risk factor in the absence of the other.