Table 3 Models considering the potential risk modification on the link between human insulin and breast cancer by other medications commonly used in patients with type 2 diabetes mellitus

Model I

 Never users of insulin

4165/345654

1.000

 Users of human insulin alone without any OAD

39/2939

1.413

(1.030-1.940)

0.0323

 OAD plus human insulin < 2 years

636/88019

0.728

(0.668-0.793)

<0.0001

 OAD plus human insulin ≥ 2 years

430/45421

0.983

(0.882-1.096)

0.7587

Model II

 Never users of insulin

4165/345654

1.000

 Users of human insulin alone or plus OAD excluding metformin

82/7827

1.127

(0.904-1.405)

0.2893

 Users of human insulin plus metformin < 2 years

23/2285

0.782

(0.519-1.178)

0.2398

 Users of human insulin plus metformin ≥ 2 years

1000/126267

0.798

(0.741-0.859)

<0.0001

Model III

 Never users of insulin

4165/345654

1.000

 Users of human insulin plus without use of statin

442/51396

0.928

(0.839-1.027)

0.1484

 Users of human insulin plus statin < 2 years

63/8601

0.654

(0.509-0.840)

0.0009

 Users of human insulin plus statin ≥ 2 years

600/76382

0.789

(0.718-0.866)

<0.0001

Model IV

 Never users of insulin

4165/345654

1.000

 Users of human insulin plus without use of ACEI/ARB

223/26367

0.822

(0.716-0.943)

0.0052

 Users of human insulin plus ACEI/ARB < 2 years

492/69952

0.745

(0.675-0.822)

<0.0001

 Users of human insulin plus ACEI/ARB ≥ 2 years

390/40060

1.005

(0.895-1.128)

0.9370