. 2017 Jun 8;32(10):909–919. doi: 10.1007/s10654-017-0250-2

Table 5.

Combined two- and three-way interaction on the additive scale between HLA-DRB1*15, absence of HLA-A*02, and smoking

Study	TotAP₃	TotRERI₃	TotSI₃
EIMS	0.6 (0.4–0.7)	6.7 (3.0–10.3)	2.9 (1.9–4.4)
GEMS	0.3 (0.2–0.5)	3.5 (1.3–5.7)	1.6 (1.2–2.1)
Danish study	0.6 (0.5–0.7)	10.8 (6.5–15.0)	2.8 (2.1–3.7)
Norwegian study	0.7 (0.5–0.9)	12.6 (1.1–24.2)	3.5 (1.6–8.0)
Nordic studies combined	0.5 (0.46–0.61)	6.8 (5.0–8.5)	2.4 (2.0–2.8)

Total attributable proportion due to interaction, relative excess risk and synergy index due to interaction, with 95% CI