Cost & Cost-Effectiveness of Implementing SD Biosensor Antigen Detecting SARs-CoV-2 Rapid Diagnostic Tests in Kenya

The COVID-19 pandemic has created a need to rapidly scale-up testing services. In Kenya, services for SARS-CoV-2 nucleic acid amplifying test (NAAT) have often been unavailable or delayed, precluding the clinical utility of the results. The introduction of antigen-detecting rapid diagnostic tests (Ag-RDT) has had the potential to fill at least a portion of the ‘testing gap’. We, therefore, evaluated the cost-effectiveness of implementing SD Biosensor Antigen Detecting SARs-CoV-2 Rapid Diagnostic Tests in Kenya. We conducted a cost and cost-effectiveness of implementing SD biosensor antigen-detecting SARS-CoV-2 rapid diagnostic test using a decision tree model following the Consolidated Health Economic Evaluation Standards (CHEERS) guidelines under two scenarios. In the first scenario, we compared the use of Ag-RDT as a first-line diagnostic followed by using NAAT assay, to the use of NAAT only. In the second scenario, we compared the use of Ag-RDT to clinical judgement. We used a societal perspective and a time horizon of patient care episodes. Cost and outcomes data were obtained from primary and secondary data. We used one-way and probabilistic sensitivity analysis to assess the robustness of the results. At the point of care, Ag-RDT use for case management in settings with access to delayed confirmatory NAAT testing, the use of Ag-RDT was cost-effective (ICER = US$ 964.63 per DALY averted) when compared to Kenya’s cost-effectiveness threshold (US$ 1003.4). In a scenario with no access to NAAT, comparing the Ag-RDT diagnostic strategy with the no-test approach, the results showed that Ag-RDT was a cost-saving and optimal strategy (ICER = US$ 1490.33 per DALY averted). At a higher prevalence level and resource-limited setting such as Kenya, implementing Ag-RDT to complement NAAT testing will be a cost-effective strategy in a scenario with delayed access to NAAT and a cost-saving strategy in a scenario with no access to NAAT assay.