Red Blood Cell Transfusion in the Ambulatory Setting: Impact on Home Functional Status

Background: Red blood cell (RBC) transfusion is frequently employed in both ambulatory and hospital environments with the aim of improving patient functional status. The efficacy of this 10.5 billion dollar per year practice however has been increasingly called into question. The Investigators propose to directly measure the impact of outpatient RBC transfusions on at-home functional status by recording several physiological parameters and quantifiable physical activity metrics, e.g. daily energy expenditure and daily total step count, using the ActiGraph wGT3X-BT. This device is an accelerometer-based wearable similar in size to a small watch and is worn at the waist. Study participants will wear the device during the course of their daily activities giving the investigators quantifiable insight into activity levels in the home environment.

Methods/Design: This will be a randomized crossover pilot clinical trial with participant study duration of 28 days. The crossover nature allows each patient to serve as his/her own control. Details of the study design are provided in the text. Briefly, patients presenting at Mayo Clinic Scottsdale's Ambulatory Infusion Center (AIC) will be randomized to one of two arms: 1) receive an RBC transfusion as scheduled (transfuse), or 2) abstain from the scheduled transfusion (no-transfuse). After an appropriate washout period, patients will cross from the transfuse arm to the no-transfuse arm or vice-versa. Activity levels will be recorded continuously throughout the study with no need for intervention by the patient. In addition to device data, survey data will be collected via a weekly telephone interview. The primary outcome measures will include both technical performance metrics such as daily energy expenditure as well as practical performance metrics such as changes in step count. A variety of secondary outcome measures include daily sedentary time and PROMIS Global 10 scores.

Discussion: This trial will directly assess the impact of red blood cell transfusion on patient functional status in the location most important - the home. Patient recruitment will begin in August 2016 and is due to be completed in August 2017.

Inclusion criteria

• Age > 18 years
• At least on prior encounter in the AIC
• Planned RBC transfusion

Exclusion criteria

• Refusal to provide informed consent
• Refusal by the health care team
• Acute ischemia (e.g. MI, CVA)
• Hemoglobin < 7.0 g/dL
• Active bleeding
• Symptomatic anemia (hypotension, tachycardia, angina, syncope/pre-syncope believed related to anemia
• Non-ambulatory functional status
• Established or Uncertain Pregnancy Status