Neutrophil-lymphocyte-ratio distributions in a Danish population from general practice

The neutrophil-lymphocyte ratio (NLR) is a novel biomarker, showing promising both diagnostic and prognostic capabilities. The aim of this study was to present NLR distributions in a Danish population from general practice (GP) and compare levels between patients from intensive care units (ICU) and GP. A register-based study was conducted using results from 31,966 blood samples from GP and ICU located in the admission area of Aarhus University Hospital, Denmark. Exclusion of samples with lymphocytes >40 × 10⁹/L, resulted in 28,582 samples from GP and 3,373 from ICU. Distributions for patients from GP with CRP <8 mg/L were age-dependent and were established for the following three age groups; 0-17 years [0.30:3.76], 18-75 years: [0.74:4.94], above 76 years: [0.89:8.80]. Patients from ICU had a significantly higher median NLR than patients from GP when stratified for CRP, [8.48 and 1.99 respectively]. This study describes for the first time the distributions of NLR in a large European population of GP patients.