(P-TS-61) Outpatient Transfusions and Transfusion-Associated Circulatory Overload (TACO) Among U.S. Medicare Beneficiaries, Ages 65 and Older, During 2016-2022

Background/Case Studies: Transfusion-Associated Circulatory Overload (TACO) is a leading cause of transfusion-related fatalities. The study assessed TACO occurrence, severity, and potential risk factors among fee-for-service Medicare beneficiaries aged 65+ transfused in the institutional outpatient setting from 2016-2022.

Study

Design/Methods: This retrospective study used Medicare databases, with procedure, revenue center, and diagnosis codes to identify outpatient transfusions and TACO occurrence on or within a day of transfusion. Study evaluated unadjusted TACO rates per 100,000 transfusion visits and 95% CIs: overall, annually, pre-pandemic (Apr 2016-Dec 2019), during COVID-19 pandemic (Jan 2020-Dec 2022), and by immunocompromised (IC) status, demographics, comorbidities, blood components, processing (e.g., irradiation [IR], leukoreduction [LR]), and number of units. Severity measures included hospitalization, ICU admission, length of stay (LOS), and inpatient mortality.

Results/Findings: Of 2,990,153 outpatient transfusion visits during 2016-2022, 1,095 had recorded TACO; an overall rate of 36.6 per 100,000 (95%CI: 34.5-38.9), ranging from 27.5 (23.1-32.8) in 2016 to 43.1 (37.0-50.3) in 2022. The TACO pre-pandemic vs. pandemic rates were 28.2 (25.9-30.8) vs. 49.1 (45.3-53.3). The rates by number of units were 31.9 (29.1-35.0) for 1 unit, 40.2 (37.2-43.4) for 2-4 units, and 72.0 (44.8-115.8) for ≥5 units. Females and males had rates of 38.3 (35.2-41.6) and 35.1 (32.3-38.2). Rates varied by age, with highest rate for ages 85+: 45.7 (40.4-51.6). The TACO rates by blood components were: 5.7 (1.4-22.7) for plasma only, 17.2 (13.6-21.7) for platelets only, 39.6 (37.2-42.3) for RBCs only, and 45.3 (37.2-55.3) for cross-product combination visits composed mostly of RBCs and platelet transfusions. The highest rate was 403.0 (201.7-803.8) for Non-IR LR Platelets and Non-IR Non-LR RBCs. The highest rates by 6-month histories of comorbidities were: congestive heart failure 53.2 (48.8-58.0), valvular disease 52.8 (48.2-57.8), and paralysis 52.8 (36.2-77.0). TACO rates for IC vs non-IC were 33.8 (31.5-36.3) and 44.3 (39.9-49.1). Non-IC vs. IC cases were more likely to be hospitalized (38.3% vs. 19.7%), and then admitted to ICU (50.7% vs. 42.5%), have LOS≥7 days (28.7% vs. 18.5%) and higher inpatient mortality (5.9% vs. 3.4%).

Conclusions: This 7-year population-based study shows higher TACO rates during pandemic vs. pre-pandemic which may be due to increased provider awareness. The study identified higher TACO risk for RBCs and product combinations, and suggested importance of comorbidities, number of units, component processing, and demographics in TACO occurrence. It also identified higher TACO risk and greater case severity among non-IC vs. IC which needs further investigations.

Importance of research: The study utilized large real-world Medicare data to assess Transfusion-Associated Circulatory Overload (TACO) occurrence, severity, and potential risk factors among fee-for-service Medicare beneficiaries aged 65+, transfused in the institutional outpatient setting during 2016-2022. This study assessed TACO occurrence before and during the COVID-19 pandemic, and by demographics, blood components, and immunocompromised (IC) status to help assure transfusion safety in the older U.S. population.