Q&A column

Editor: Frederick L. Kiechle, MD, PhD

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Q. Are there established benchmarks for such transfusion services quality monitors as C:T ratio, blood product waste, and cancellation of suboptimal specimens?

A.February 2022—Unfortunately, there are few studies that meet the strictest definition of benchmarking within transfusion medicine.¹ In addition, we have not found a source that provides suggested transfusion medicine quality improvement monitors with associated target benchmark values.

There are member-based organizations that provide benchmarking databases that allow health care institutions to compare their key performance measures against those of similar-sized organizations or against national aggregated data. Alternatively, institutions can perform their own auditing of key performance measures to detect potential inefficiencies or inappropriate use of resources.^2,3 Below are findings from several studies that provide individual or aggregated multi-institutional data with benchmarks for quality monitors in transfusion medicine.

Crossmatch to transfusion (C:T) ratio. This metric assesses the efficiency of a clinical team’s blood-ordering practices versus its use of blood. Ideally the C:T ratio should be 1:1. However, most studies endorse a goal C:T ratio of less than 2 or 2.5 to provide a safety margin for unexpected hemorrhage.^4,5 A study of transfusion practices at more than 1,600 institutions revealed that the top 10 percent of institutions had a C:T ratio of less than 1.5, while the lowest performers had a C:T ratio of greater than 2.4. Based on the results, the authors of the study recommended a C:T ratio of less than 2.⁶

A C:T ratio of greater than 2 for a clinical service line or per surgical procedure type would be flagged as potentially inappropriate and should prompt the transfusion service to discuss with the clinical service whether to modify ordering and transfusion practices.

Crossmatch to issue (C:I) ratio. This quality indicator, first proposed by Lin, et al., assesses how often a crossmatched unit is issued. It is evaluated independently of the clinical services’ utilization and is not linked to disposition of the blood (whether it is wasted, returned, or transfused). This metric reflects how the transfusion service manages and uses blood inventory.⁷

An international survey of 52 institutions noted that the C:I ratio differed among institutions based on the predominant testing method used (electronic crossmatch versus serologic crossmatch) and whether crossmatching was performed when the product order was received or when the product was issued. Based on the results, the authors proposed a target C:I ratio benchmark of less than 1.15.⁸

Blood product waste. There are many ways to measure and calculate waste, so an institution should define the metric it wants to use. The transfusion service should decide whether to include or separate out expired units caused by inventory mismanagement and determine the desired method of calculation. These decisions will allow the institution to compare similar benchmark measures. Several studies provide data on waste rates for blood components for comparison purposes.^6,9,10

A red blood cell waste rate of less than one percent generally is achievable and is a reasonable benchmarking goal.^6,11 A CAP Q-Probes study differentiates expired blood components from other sources of waste. This study proposed that institutions adopt a goal expiration rate of less than one percent and a waste rate of less than 0.5 percent.⁶

Another CAP Q-Probes study focused on the expiration rate of plasma and platelets. The study reported that top-performing institutions had an expiration rate for plasma and platelets of less than 0.6 percent, while lower-performing institutions had an expiration rate of greater than 13.8 percent. Likewise, high performers had a waste rate of less than 0.5 percent and low performers had a waste rate of greater than 6.8 percent. This study concluded that institutions can achieve plasma and platelet expiration rates below one percent.