Candidate for the Lee B. Lusted Student Prize Competition
Purpose: Babesiosis is the most common transfusion-transmitted infection in the US and frequently results in severe or fatal illness in immunocompromised blood recipients.� Blood donor screening assays are currently investigational and not widely employed in endemic areas.� We evaluated the cost-effectiveness of 4 screening strategies for prevention of transfusion-transmitted babesiosis.
Methods: � A decision analytic model compared the cost-effectiveness of screening using (1) questionnaire (status quo) (2) universal immunofluorescence antibody (IFA) assay (3) universal IFA and polymerase chain reaction (PCR) and (4) recipient risk-based targeting whereby a proportion of blood is IFA/PCR screened and reserved for immunocompromised recipients. Data were from published sources, including the recently published 1 year experience of risk-based targeting at the Rhode Island Blood Center.� �A societal perspective with a time horizon of 1 year was adopted.� Outcomes included screening and treatment costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness (CE) ratios ($/QALY). Uncertainty was evaluated through 1-way, 2-way and probabilistic sensitivity analysis.�
Results: � In the base case, IFA screening had a CE ratio of $12,400 compared to status quo, IFA and PCR had an incremental CE ratio of $103,700 and the targeted strategy was excluded due to extended dominance.� In 1-way sensitivity analyses the optimal screening strategy was sensitive to prevalence, testing costs, and the likelihood of donor window period infection.� ��In probabilistic sensitivity analysis at a threshold of $100,000/QALY, IFA/PCR screening had a 55.7% probability of being the optimal strategy at 0.58% base case prevalence versus 2.1% at 0.1% prevalence and 91.5% at 1.4% prevalence.
Conclusions: � Where babesia prevalence exceeds 0.1%, the CE ratio for IFA screening provides significantly better value for money than questionnaire and at prevalence exceeding 0.6% the incremental CE ratio for IFA/PCR screening is more attractive than many currently adopted blood safety interventions (Figure). �More information on epidemiology and the accuracy of screening assays is needed to inform the optimal strategy for a national policy, but our results demonstrate a cost-effective means to improve blood safety in endemic areas.� �� 