Institutional analysis of crossmatch-to-transfusion ratios at a tertiary hospital

Efficient blood utilization is increasingly essential in Korea due to increasing transfusion demand and a declining donor pool. The crossmatch-to-transfusion (C/T) ratio reflects ordering efficiency; however, long-term institutional-level analyses are rare. This study examined 10-year C/T ratio trends and blood utilization patterns at a major tertiary hospital.

We retrospectively analyzed red blood cell usage at Asan Medical Center between 2015 and 2024. Annual data on transfused units, completed crossmatches, and canceled crossmatch requests were obtained from the institutional blood bank information system. The C/T ratio was calculated as crossmatched units divided by transfused units. Autologous transfusions, whole blood transfusions, and massive transfusion protocol activations were excluded. Trends were assessed by usage type (ward, surgery, outpatient, and emergency) and by department.

Annual transfused units ranged from 59,731 to 86,063, with institutional C/T ratios stable at 1.12-1.17. Surgical services exhibited the highest cumulative C/T ratio (1.55), whereas outpatient utilization exhibited the lowest (1.03). Ward and emergency services exhibited intermediate ratios (1.04 and 1.05, respectively), with gradual improvement over time. In 2024, most departments maintained efficient ratios of 1.02-1.10; higher ratios were observed in the Pediatric Surgery (1.52) and Vascular Surgery (1.33) departments.

This decade-long study demonstrated efficient blood utilization with significant variation across clinical settings. These findings suggest that a single universal C/T ratio may be inappropriate; interpretation should consider specific operational context, particularly between surgical and nonsurgical services. These findings provide a foundation for multi-center studies to develop standardized transfusion efficiency metrics.