Estimating the incidence of transfusion-associated circulatory overload using active surveillance: A systematic review and meta-analysis.

Background: Transfusion-associated circulatory overload (TACO) is an adverse event that is the leading cause of transfusion-related death. It is underrecognized, and the aim of this study was to synthesize the available evidence from active surveillance studies to estimate its incidence.

Study design and methods: This study is a systematic review and meta-analysis of publications reporting TACO incidence using active surveillance. A research librarian searched Medline and Embase, identifying publications between January 1991 and June 2024. Studies reporting TACO either by patient, blood component (red blood cells [RBCs], platelets, or plasma) or transfusion episode were identified, and all patient settings were eligible. A random effects model estimated TACO incidence, and potential sources of heterogeneity were evaluated using meta-regression.

Results: Twenty-two studies met eligibility criteria and were included for analysis. The rate per patient was 22.2/1000 (95% CI: 16.2-29.2) based on 21 studies. The rate estimate of TACO among total blood components (RBCs, plasma, and platelets combined) reported in 10 studies was 2.2/1000 units transfused (95% CI: 1.2-3.5/1000). There was substantial between-study variation in rates and more recent studies tended to report higher rates. Although the platelet point estimate was higher than the point estimates for RBCs and plasma, the confidence intervals overlapped. Only two studies reported TACO rates per transfusion episode and the pooled estimate was 6.3/1000 (95% CI: 1-16.3/1000), about three times greater than the overall per unit estimate.

Discussion: Clinicians should consider quantitative risks of important transfusion-related harms, such as TACO, when making the decision to transfuse.