Monocyte distribution width (MDW) as an infection indicator in severe patients attending in the Emergency Department: a pilot study

Background. The aim of the present study was to evaluate the diagnostic performance of monocyte distribution width (MDW) as a biomarker for sepsis diagnosis in severe patients attended in the Emergency Department for different conditions and not only infections. Methods. We performed an observational study in a consecutive prospective cohort including severe patients attending the Emergency Department with different conditions. MDW and other biomarkers were determined from samples obtained during the first care of patients. The diagnostic performance of the different biomarkers was determined based on the final diagnosis at patient discharge. Results. One hundred two patients, with a mean age of 76.7 (SD 16.5) years were included, 53 being (51.9%) male. Among the patients included, 65 (63.7%) had an infectious disease while the remaining had other different conditions. A MDW cut-off of 20.115 provided the best accuracy to identify infected patients, with a sensitivity of 89.2 (95% CI 79.494.7), a specificity of 89.2 (95% CI 75.3-95.7), a positive predictive value of 93.5 (95% CI 84.6-97.5), a negative predictive value of 82.5% (95% CI 68.0-91.3), a positive likelihood ratio of 8.25 (3.26-20.91), and a negative likelihood ratio of 0.12 (0.06-0.24). The area under the receiver operating characteristic curve for infection according to MDW was 0.943 (95% CI 0.897-0.989; p<0.001). Conclusions. A MDW > 20.115 may be associated with infection and could help to distinguish between infected and non-infected patients in severe patients. These results must be confirmed in new studies due to the limited patient sample included.