Neutrophil to Lymphocyte Count Ratio as an Indicator of BSI
Neutrophil to Lymphocyte Count Ratio as an Indicator of BSI
A total of 2002 patients (50% male, median age 66 years) met the inclusion criteria. Complete data were available for 1954. In 48 patients, positive blood cultures were attributed to skin contamination. Blood cultures were deemed to be truly positive in 270 patients, giving a prevalence of bacteraemia of 13.8%. Gram-negative species predominated among the bacteraemic patients, accounting for 154 isolates (57%), of which Escherichia coli contributed just over half (n=78). Streptococcus and Staphylococcus spp accounted for the Gram-positive cases in equal measure.
The results of the analyses are presented in Table 1 and Table 2 . The distribution of WCC was similar in bacteraemic and non-bacteraemic patients (Mann–Whitney U test; p=0.064). All other variables were significantly differently distributed (p<0.001).
ROC curves (with SE) for each parameter are presented in figures 1 and 2. NLCR and LC produced the highest AUC at 0.71.
(Enlarge Image)
Figure 1.
Receiver Operating Characteristic curves. WCC, white cell count; NC, neutrophil count; LC, lymphocyte count; NLCR, neutrophil lymphocyte ratio; CRP, C-reactive protein.
(Enlarge Image)
Figure 2.
Areas under the Receiver Operating Characteristic curves. WCC, white cell count; NC, neutrophil count; LC, lymphocyte count; NLCR, neutrophil lymphocyte ratio; CRP, C-reactive protein.
Results
A total of 2002 patients (50% male, median age 66 years) met the inclusion criteria. Complete data were available for 1954. In 48 patients, positive blood cultures were attributed to skin contamination. Blood cultures were deemed to be truly positive in 270 patients, giving a prevalence of bacteraemia of 13.8%. Gram-negative species predominated among the bacteraemic patients, accounting for 154 isolates (57%), of which Escherichia coli contributed just over half (n=78). Streptococcus and Staphylococcus spp accounted for the Gram-positive cases in equal measure.
The results of the analyses are presented in Table 1 and Table 2 . The distribution of WCC was similar in bacteraemic and non-bacteraemic patients (Mann–Whitney U test; p=0.064). All other variables were significantly differently distributed (p<0.001).
ROC curves (with SE) for each parameter are presented in figures 1 and 2. NLCR and LC produced the highest AUC at 0.71.
(Enlarge Image)
Figure 1.
Receiver Operating Characteristic curves. WCC, white cell count; NC, neutrophil count; LC, lymphocyte count; NLCR, neutrophil lymphocyte ratio; CRP, C-reactive protein.
(Enlarge Image)
Figure 2.
Areas under the Receiver Operating Characteristic curves. WCC, white cell count; NC, neutrophil count; LC, lymphocyte count; NLCR, neutrophil lymphocyte ratio; CRP, C-reactive protein.
