Table 3 Subgroup analysis for the association between SII and COPD

Age group

0.454

 40–59 years

ref

0.897(0.638,1.261)

1.456(1.046,2.025)

0.023

 >=60 years

ref

1.162(0.886,1.524)

1.816(1.430,2.307)

< 0.0001

Gender

0.918

 Male

ref

1.056(0.767,1.453)

1.654(1.248,2.192)

< 0.001

 Female

ref

0.987(0.729,1.336)

1.662(1.284,2.152)

< 0.001

Smoking status

0.025

 never

ref

0.693(0.417,1.154)

0.951(0.542,1.668)

0.891

 former

ref

1.033(0.751,1.422)

2.005(1.557,2.583)

< 0.0001

 now

ref

1.358(0.950,1.941)

1.602(1.070,2.399)

0.023

BMI group

0.929

 <25

ref

1.073(0.730,1.577)

1.643(1.153,2.340)

0.008

 >=25

ref

0.995(0.770,1.285)

1.639(1.302,2.062)

< 0.0001

History of hypertension

0.759

 no

ref

1.102(0.785,1.546)

1.717(1.201,2.455)

0.004

 yes

ref

0.945(0.750,1.190)

1.542(1.223,1.944)

< 0.001

History of diabetes

0.767

 no

ref

0.939(0.710,1.243)

1.547(1.185,2.019)

0.001

 IFG and IGT

ref

1.149(0.528,2.498)

1.857(0.908,3.799)

0.08

 DM

ref

1.338(0.813,2.204)

1.961(1.365,2.817)

< 0.001

History of CVD

0.552

 no

ref

1.086(0.849,1.387)

1.735(1.335,2.254)

< 0.0001

 yes

ref

0.931(0.644,1.345)

1.383(0.969,1.975)

0.062