Age of Blood Does Not Affect Quality of Life and Hemoglobin: N– of −1 Trials in Transfusion-Dependent Patients,

Abstract 3369

Introduction Red blood cell concentrates (RBCs) are stored for up to 42 days. Prolonged storage of RBCs results in “the storage lesion” which has been associated with adverse outcomes in patients with critical illness, sepsis, and post-cardiac surgery. No studies have assessed the impact of the storage lesion on the quality of life (QoL) of patients who require chronic transfusion support. This study assessed the effects of fresh versus standard issue blood on QoL and follow-up hemoglobin (Hb) in transfusion-dependent patients.

Methods Transfusion-dependent patients age 18 years or older, were invited to participate in an N-of-1 trial. Transfusion dependence required at least one unit of RBCs every four weeks. Each participant was randomly assigned four fresh (less than seven days of storage) and four standard issue (seven to 42 days of storage) blood transfusions. Investigators, study participants, treating physicians, and nurses were blinded to product allocation. A questionnaire containing a visual analog scale (VAS) and the Functional Assessment of Cancer Therapy-Anemia questionnaire (FACT-An) was completed prior to and 24 hours after each transfusion. Changes were calculated as post-transfusion scores minus pre-transfusion scores. Hemoglobin levels were measured at each subsequent transfusion. Within-subject (each participant) between-treatment comparisons of QoL scores and hemoglobin levels were assessed by unpaired t-tests among participants who completed at least six transfusions. Between-group changes in QoL scores for all participants were assessed by paired t-tests and a mixed model approach.

Results Twenty patients were enrolled (mean age 66.8 years, 12 females). Underlying diagnoses included myelodysplastic syndromes (12), β-thalassemia (3), myeloproliferative neoplasms (3), Diamond-Blackfan anemia (1), and chronic anemia of undetermined etiology (1). Mean ages of fresh and standard blood were 4.0 days and 23.2 days, respectively. Nine participants completed at least six transfusions. Among remaining participants, nine were non-compliant, and two died. All data were analysed in the between-group comparisons. There were no statistically significant differences in the effect of standard blood and fresh blood on the eight QoL parameters assessed in all analyses. This was seen in the within subject between-group analysis as well as the between-group analysis. Similarly, there were no statistically significant differences in the effect of standard blood and fresh blood on follow-up Hb levels.

Conclusions No significant differences in QoL parameters or follow-up Hb levels were observed in patients receiving fresh versus standard issue blood. These results suggest that local blood transfusion laboratory practices do not need to be altered for transfusion-dependent patient populations. To our knowledge, this is the first study to assess the QoL effects of age of blood on transfusion-dependent patients using N-of-1 trials. While larger studies are needed to confirm these findings, our results demonstrate that N-of-1 studies are feasible and informative in the management of individual patients. The randomized controlled multiple crossover design of N-of-1 studies may be also useful in addressing questions in transfusion medicine regarding differences in the quality of blood products.