This study will establish the clinical performance of the Monocyte Distribution Width (MDW) parameter on the DxH 900/ DxH 690T hematology analyzers to aid in the detection and risk assessment of patients in the Emergency Department (ED) for progression to sepsis.

The objective of this study is to validate the MDW dual cut-off values established during characterization and demonstrate the performance of MDW to detect sepsis in a multi-center study of adults presenting to the ED who have CBC w/diff ordered within 12 hours of presentation.

This study is designed to enroll all-comers from selected sites that currently have a DxH 900 in use as part of routine testing in the ED. All subjects who meet the Inclusion Criteria will be included in the study, without enrichment. Data from all subjects meeting the Inclusion Criteria will be provided to a panel of independent adjudicators. Adjudicators will be blinded to the MDW result and any sepsis diagnostic determinations which may or may not be in the original medical record.

Inclusion Criteria:

• Adults (18 to 89 years) of all races and ethnicities presenting to the ED
• Whole Blood venous samples collected in K2EDTA while the patient was in the ED
• First CBC w/diff test ordered within 12 hours of presentation to ED as part of their standard medical care
• CBC w/diff tested within 2 hours of specimen collection
• Subjects with at least ≥12 hours of follow-up in the ED (or inpatient, if admitted) from presentation

Exclusion Criteria:

• CBC w/diff test ordered after 12 hours of presentation to ED
• Subjects previously enrolled in this study (i.e. subjects may not be enrolled more than once in this study)
• Subjects discharged from ED <12 hours from ED presentation
• ED Transfer Patients

Data Exclusions Post Enrollment:

• Samples that have a system generated flag from the Standard of Care (SOC) CBC w/diff testing will be excluded.
• Samples with instrument flags, including vote outs and review flags for MDW will also be excluded (i.e. invalid MDW results).
• Subjects' data collected with Instrument Quality Control failure(s).

All-comers study of adult patients (18 to 89 years) of all races and ethnicities presenting to the ED