TABLE 4

Multivariate Cox regression examining association between blood leukocyte indexes and 1) mortality in early fibrotic interstitial lung abnormalities (EF-ILA) (n=1259) and 2) radiological progression in the EF-ILA cohort with available repeat computed tomography scans for comparison (n=362)

MortalityRadiological progression
HR (95% CI)p-valueHR (95% CI)p-value
MLR
 Age1.03 (1.01–1.06)0.006*1.02 (0.99–1.05)0.113
 Gender1.00 (0.74–1.36)0.9950.92 (0.67–1.27)0.624
MLR1.16 (1.02–1.31)0.025*2.28 (1.33–3.87)0.002*
NLR
 Age1.03 (1.01–1.06)0.007*1.02 (0.99–1.05)0.122
 Gender0.98 (0.72–1.34)0.9100.96 (0.70–1.32)0.814
 NLR1.07 (1.05–1.09)<0.0001*1.07 (1.01–1.14)0.024*
SIRI
 Age1.04 (1.01–1.06)0.003*1.03 (0.99–1.05)0.079*
 Gender1.02 (0.75–1.38)0.9240.96 (0.69–1.31)0.789
 SIRI1.06 (1.04–1.08)<0.0001*1.09 (1.04–1.14)0.0002*

Each leukocyte index, age and gender is a separate model. Similar findings were observed when leukocyte indexes were adjusted for respiratory comorbidity and when adjusted for coefficient of variation over a year (supplementary tables S3 and S4). MLR: monocyte:lymphocyte ratio; NLR: neutrophil:lymphocyte ratio; SIRI: systemic inflammatory response ((monocytes×neutrophils) ÷ lymphocytes). *: p<0.05.