3.4 Discussion

Adding whole blood PI to the existing blood safety portfolio in Ghana would prevent many transfusion-related adverse events and may decrease overall healthcare spending. We estimated a 63% probability that whole blood PI would lead to a net reduction in healthcare costs, but this increased to 89% when factoring in healthcare costs for one secondary case for each HIV, HBV, and HCV infection. Our analysis did not consider non-healthcare costs such as family caregiver time, productivity loss, or transportation costs. We also did not evaluate all types of adverse events for which PI may reduce risk, which could include emerging infectious diseases not yet identified as blood safety threats, and we did not quantify the associated reductions in death and disability. Due to these factors, the total societal benefit of PI likely exceeds the impact on direct healthcare spending as estimated here.

We employed a detailed approach to estimating the costs of adverse events that accounted for subclinical disease and the timing and likelihood of chronic disease detection. This approach, combined with other developments such as price reductions for some resources such as HIV antiviral therapy drugs [114] and greater immunity to HBV through vaccination [115], led to lower estimates of the per-infection costs for HBV, HCV, and HIV events as compared to past analyses of blood safety interventions in sub-Saharan Africa [85,110,116]. Our analysis also suggested that bacterial sepsis is an underappreciated blood safety threat in sub-Saharan Africa, accounting for large percentage of transfusion-related adverse events cases and the majority of associated healthcare spending.

This study has several limitations. Data on the rate of transfusion-related adverse events in Ghana, and in sub-Saharan Africa generally, are limited. The benefit of PI depends on the baseline residual risk of each adverse event, and updated risk estimates from recent hemovigilance data could increase accuracy. While our detailed micro-costing approach to estimating the disease trajectories and associated healthcare costs for adverse events was based on clinical expertise, a rigorous empirical study may reduce uncertainty. For most diseases, the modeled risk reduction due to PI was based on estimates from prior modeling study because the low baseline rate of these adverse outcomes makes empirical estimation difficult. Our finding that PI is likely cost-saving was sensitive to uncertainty in some input parameters, most notably parameters that influence the likelihood and cost of clinically overt bacterial sepsis infections.

Our analysis provides further evidence that PI is a promising technology for sub-Saharan Africa. Future research could further elucidate the societal impact of PI and other blood safety technologies by improving estimation of the burden of illness from transfusion-related adverse events, estimating other impacts beyond direct healthcare spending, and considering other settings in sub-Saharan Africa.