Clinical question: Is hospital acquired anemia associated with increased postdischarge adverse outcomes?
Background: Hospital acquired anemia (HAA) is defined as the development of anemia during the course of a hospitalization when starting with a normal hemoglobin on admission. The incidence of HAA is at least 25% when using the last hemoglobin prior to discharge as the index value. HAA is felt to be potentially preventable and usually iatrogenic due to phlebotomy.
Study design: Observational cohort study.
Setting: Six northern Texas hospitals.
Synopsis: There were 11,309 index hospitalizations with a median hematocrit value on admission of 40.6 g/dL. The authors defined HAA as a normal hematocrit value within the first 24 hours of admission and a hematocrit value lower than the WHO sex-specific cut points at the time of discharge: mild HAA (hematocrit greater than 33% and less than 36% in women, greater than 33% and less than 40% in men), moderate HAA (greater than 27% and less than 33%), and severe HAA (less than 27%). Mild HAA occurred in 21.6% of patients, with 10.1% of patients developing moderate HAA, and 1.4% developing severe HAA (85% underwent major procedure, diagnosis of hemorrhage or coagulation/hemorrhagic disorder). Predictors of developing moderate/severe HAA included undergoing a major diagnostic or therapeutic procedure, female sex, elective admission, hospital LOS, BUN to creatinine ratio greater than 20:1, and serum creatinine on admission. Development of severe HAA was associated with a 41% increase in the odds of 30-day readmission and a 39% increase in the odds of the composite outcome (30-day mortality and 30-day readmission).
Bottom line: Severe HAA had significant increased odds of 30-day readmission and mortality, but might not be as preventable as initially thought given the frequency of major procedures and hemorrhage in those that developed severe HAA.
Citation: Makam AN, Nguyen OK, Clark C, Halm EA. Incidence, predictors, and outcomes of hospital-acquired anemia. J Hosp Med. 2017;12(5):317-22.
Dr. Newsom is a hospitalist at Ochsner Health System, New Orleans.