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

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.w 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. Journal of Hospital Medicine 2007;2:5–12. © 2007 Society of Hospital Medicine.