Which observations from the complete blood cell count predict mortality for hospitalized patients?

Abstract

Background: Information on the prognostic utility of the admission complete blood count (CBC) and differential count is lacking.

Objective: To identify independent predictors of mortality from the varied number and morphology of cells in the complete blood count defined as a hemogram, automated five cell differential count and manual differential count.

Design: Retrospective cohort study and chart review.

Setting: Wishard Memorial Hospital, a large urban primary care hospital.

Patients: A total of 46,522 adult inpatients admitted over 10 years to Wishard Memorial Hospital-from January 1993 through December 2002.

Intervention: None.

Measurements: Thirty-day mortality measured from day of admission as determined by electronic medical records and Indiana State death records.

Results: Controlling for age and sex, the multivariable regression model identified 3 strong independent predictors of 30-day mortality-nucleated red blood cells (NRBCs), burr cells, and absolute lymphocytosis-each of which was associated with a 3-fold increase in the risk of death within 30 days. The presence of nucleated RBCs was associated with a 30-day mortality rate of 25.5% across a range of diagnoses, excluding patients with sickle-cell disease and obstetric patients, for whom NRBCs were not associated with increased mortality. Having burr cells was associated with a mortality rate of 27.3% and was found most commonly in patients with renal or liver failure. Absolute lymphocytosis predicted poor outcome in patients with trauma and CNS injury.

Conclusions: Among patients admitted to Wishard Memorial Hospital, the presence of nucleated RBCs, burr cells, or absolute lymphocytosis at admission was each independently associated with a 3-fold increase in risk of death within 30 days of admission.