More with Less: Evaluating Transfusion Practices in Oncology Patients

Background:

Recent guidelines support restrictive blood transfusion practices in the majority of patients.  However, the National Comprehensive Cancer Network continues to recommend a goal hemoglobin (Hgb) range of 7-9 g/dL in the oncology patient population.  The oncology services at our institution typically use a Hgb threshold of 8 g/dL to dictate need for transfusion. Transfusion-associated risks have been well documented, suggesting that variable transfusion practices among oncology patients likely have clinical implications. We sought to examine variation in transfusion practices and provider characteristics associated with lower threshold for transfusion in oncology patients.

Methods:

We surveyed internal medicine residents, hospitalists, and medical oncologists at a large urban hospital in Chicago, IL. Eligible participants cared for inpatients on general medicine and hematology-oncology units between August 2013 and June 2014. The web-based survey included three different patient scenarios to assess transfusion practices: a generally healthy patient, a patient with solid tumor malignancy and a patient with hematologic malignancy.  We evaluated transfusion thresholds (<7 or >7 g/dL) for each scenario and compared thresholds based on physician type and years in practice.

Results:

Our response rate was 61.3% (49/80) for residents, 61.2% (30/49) for hospitalists, and 62.1% (18/29) for oncologists, for a total response rate of 61.4%. Non-residents had variable levels of clinical experience (0-3 years (12.0%), 4-7 years (14.1%), 8-12 years (15.2%) and >13 years (8.7%). 

For a generally healthy patient, 95.9% of residents, 91.3% of hospitalists and 62.5% of oncologists use a transfusion threshold of Hgb < 7 g/dL (p=0.02). For a patient with solid tumor malignancy, 72.0% of residents, 68.2% of hospitalists and 47.1% of oncologists transfuse at < 7 g/dL (p=0.15). For a patient with hematologic malignancy, 72.0% of residents, 61.9% of hospitalists and 40.0% of oncologists transfuse at Hgb < 7 g/dL (p=0.07).

Differences in transfusion thresholds also varied by years in practice. For a generally healthy patient, 94% of physicians (including residents) in practice ≤12 years chose a Hgb threshold of <7 g/dL, while 14% of physicians in practice ≥13 years chose this threshold (p=0.0001). For a patient with solid tumor malignancy, the percentages were 71 v. 13 (p=0.02), and for a patient with hematologic malignancy, 67 v. 25 (p=0.07). 

Conclusions:

We found that transfusion thresholds differed based on years in practice and patient scenario. Fewer years in practice was predictive of lower hemoglobin thresholds. Further research is needed to determine how variable transfusion practices impact clinical outcomes in this patient population.