Patient factors associated with transfusion practices in Veterans Affairs intensive care units: implications for further research.

PURPOSE: We sought to describe how patient characteristics influence the frequency of red blood cell (RBC) transfusions among critically ill patients after taking into account hemoglobin (Hgb) level.

METHODS

This was a retrospective cohort study using secondary analysis of administrative data of Veterans Affairs intensive care unit (ICU) admissions. The outcome of interest was RBC transfusion during the first 30 days of ICU admission. Besides Hgb level, explanatory variables included demographics, admission-related information, comorbid conditions, ICU admission diagnosis, and selected laboratory test results. Logistic regression modeling quantified associations between explanatory variables and transfusion.

RESULTS

For 259 281 ICU admissions from 2001 to 2005, the overall incidence of RBC transfusion was 12.5%. Increased age, male gender, admission for acute myocardial infarction (AMI), and comorbid heart disease were independently associated with transfusion. Compared with admission for reference diagnoses, transfusions were more likely for admissions for AMI, unstable angina, and congestive heart failure only at Hgb levels below 11, 9, and 6 g/dL, respectively.

CONCLUSIONS

Intensive care unit patients admitted for AMI, unstable angina, and congestive heart-failure had higher likelihood of receiving RBC transfusions below specific Hgb levels varying from 6 to 11 g/dL. Further research is needed to determine how these transfusion practices influence outcomes.