Skip to main content

Table 3 Factors independently associated with IL-6 serum levels in the multivariate linear regression and in the bootstrapping regression model (N = 527)

From: Predictors of circulating INTERLEUKIN-6 levels in head and neck cancer patients

Factors Categories Multivariate linear regression Bootstrapping regression model
β (SE) 95% CI P-value β (SE) 95% CI P-value
Age (years) Continuous 0.01 (0.003) 0.01; 0.02 <  0.0001 0.01 (0.003) 0.01; 0.02 <  0.0001
Sex Female Reference    Reference   
Male 0.26 (0.07) 0.12; 0.41 0.0005 0.26 (0.07) 0.12; 0.40 0.0005
Current body mass index (kg/m2) <  18.5 0.08 (0.16) −0.23; 0.38 0.63 0.07 (0.14) −0.21; 0.38 0.63
≥ 18.5 < 30 Reference    Reference   
≥ 30 0.27 (0.07) 0.12; 0.41 0.0003 0.27 (0.07) 0.14; 0.40 0.0003
Marital status Not married Reference    Reference   
Married - 0.16 (0.07) −0.29; −0.03 0.02 −0.16 (0.07) −0.29; − 0.02 0.02
Karnofsky Performance Status (%) 90–100 Reference    Reference   
60–80 0.38 (0.11) 0.17; 0.58 0.0004 0.37 (0.12) 0.16; 0.64 0.0004
Charlson Comorbidity Index 0 Reference    Reference   
1 0.15 (0.07) 0.01; 0.28 0.03 0.15 (0.08) 0.01; 0.31 0.03
≥ 2 0.23 (0.08) 0.07; 0.40 0.006 0.23 (0.07) 0.10; 0.39 0.006
Glottic cancer No Reference    Reference   
Yes −0.28 (0.06) −0.40; −0.16 <  0.0001 − 0.28 (0.06) − 0.41; − 0.16 <  0.0001
Tobacco consumption (all tobacco products) Never Reference    Reference   
Former 0.43 (0.13) 0.17; 0.69 0.001 0.43 (0.11) 0.21; 0.63 0.001
Current 0.51 (0.14) 0.23; 0.79 0.0004 0.51 (0.12) 0.26; 0.74 0.0004
  1. β is the parameter estimate associated with the increment of one unit of ln IL-6; CI Confidence interval, SE Standard error