Table 4 Subgroup of Relationship between systemic immune-inflammation index (SII) and all cause mortality

Age

0.39

 20–39

ref

2.09(0.62, 7.04)

3.79(1.39,10.31)

2.29(0.64, 8.17)

0.32

 40–59

ref

0.94(0.49,1.79)

1.14(1.03,2.04)

1.74(1.46,3.12)

0.02

 ≥ 60

ref

1.06(0.77,1.45)

1.05(0.78,1.43)

1.76(1.37,2.27)

< 0.0001

Sex

0.56

 Female

ref

0.95(0.61,1.46)

1.10(0.78,1.56)

1.75(1.25,2.44)

< 0.0001

 Male

ref

1.18(0.74,1.91)

1.65(1.14,2.37)

2.40(1.68,3.42)

< 0.0001

BMI

0.06

 <30

ref

0.62(0.23,1.67)

1.01(0.43,2.37)

0.56(0.24,1.29)

0.32

 ≥30

ref

0.86(0.45,1.65)

1.35(1.17,1.72)

1.91(1.37,2.60)

0.01

Race

0.74

 non-Hispanic white

ref

0.99(0.62,1.56)

1.29(0.90,1.85)

2.07(1.44,2.99)

< 0.0001

 non-Hispanic black

ref

1.20(0.76,1.87)

1.35(0.87,2.10)

1.69(0.98,2.90)

0.06

 Mexican American

ref

0.92(0.30, 2.81)

1.16(0.47, 2.90)

0.87(0.28, 2.68)

0.82

 Others

ref

0.92(0.37,2.25)

0.99(0.42,2.32)

1.22(0.48,3.11)

0.59

Smoking status

0.18

 Now

ref

0.80(0.40, 1.58)

1.77(1.04, 3.00)

2.02(1.22, 3.32)

< 0.001

 Former

ref

1.16(0.72,1.88)

1.02(0.63,1.68)

2.04(1.32,3.16)

< 0.001

 Never

ref

1.04(0.63,1.72)

1.21(0.74,1.97)

1.37(1.13,2.76)

0.40

Marital status

0.15

 Married/living with partner

ref

1.37(0.85,2.19)

1.29(0.85,1.96)

2.24(1.45,3.46)

< 0.0001

 Widowed/divorced

ref

0.62(0.40,0.95)

1.04(0.71,1.52)

1.57(1.11,2.21)

< 0.0001

 Never married

ref

1.29(0.40, 4.19)

2.43(1.01, 5.86)

1.73(0.78, 3.84)

0.20

DM

0.71

 No

ref

1.26(0.75,2.11)

1.25(0.80,1.95)

1.94(1.22,3.07)

< 0.001

 Yes

ref

0.99(0.68,1.43)

1.33(0.96,1.85)

1.21(1.17,2.68)

0.10

CVD

0.18

 No

ref

0.96(0.65,1.43)

1.44(1.02,2.05)

1.28(1.08,1.49)

0.15

 Yes

ref

1.07(0.66,1.72)

1.02(0.64,1.62)

0.90(0.34,2.68)

0.20

Hypertension

0.12

 No

ref

0.81(0.44, 1.46)

1.17(0.67, 2.04)

1.22(0.76, 1.96)

0.17

 Yes

ref

1.20(0.85,1.71)

1.28(0.94,1.75)

2.22(1.60,3.06)

< 0.0001