Comparison between a rapid diagnostic test and dried blood spot-based immunoassay for hepatitis B surface antigen testing: Performance and cost implications in a population-based serosurvey in Vietnam.

OBJECTIVES: This study aimed to determine the agreement between a rapid diagnostic test (RDT) and a dried blood spot (DBS)-based electrochemiluminescence immunoassay (ECLIA) of hepatitis B surface antigen and to compare the costs of conducting serosurveys using RDTs and DBS in a field setting. METHODS: A serosurvey was conducted in the South Central Coast region of Vietnam in May 2019. Participants aged 1-39 years were recruited using a four-stage random sampling method and tested for hepatitis B surface antigen using an RDT kit (Alere Determine) and a DBS-based ECLIA. The agreement between the RDT and the DBS-based ECLIA was assessed using cross-tabulation and Cohen kappa. Cost data were categorized by input (personnel, transportation, field consumables, laboratory consumables, and capital item/overhead) and survey phase (survey preparation, data/biospecimen collection, laboratory testing, and coordination). RESULTS: A total of 2072 participants were analyzed. There was a 99% agreement between the RDT and the DBS-based ECLIA results, with a Cohen kappa of 0.9. The estimated cost of conducting a serosurvey by DBS was UD $75,291, whereas RDT was $53,182. CONCLUSION: RDTs and DBS-based ECLIA provide test results with high agreements. RDTs are a better option in terms of cost, whereas the DBS-based ECLIA may be useful when evaluating multiple infectious diseases.

Cost-effectiveness of managing HBV reactivation in patients with resolved HBV infection treated with anti-CD20 antibody for B-cell non-Hodgkin lymphoma.

There is no universal recommendation for managing the reactivation of HBV in patients with resolved HBV infection treated with anti-CD20 monoclonal antibodies for B-cell non-Hodgkin lymphoma. This study compared the cost-effectiveness of two commonly used strategies: prophylactic anti-HBV nucleos(t)ide analog therapy (Pro NAT), and HBV DNA monitoring followed by on-demand antiviral therapy (HBV DNA monitoring). Using a decision tree model, the incremental cost-effectiveness ratio (ICER) expressed as cost per quality-adjusted life-year (QALY) gained was calculated. The threshold for cost-effectiveness was set at 5,000,000 JPY, equivalent to 45,662 USD. In a base-case analysis, HBV DNA monitoring was found to be more cost-effective based on the calculation of ICER as 132,048 USD per QALY, a value that far exceeds 45,662 USD. The same results were consistently obtained by a one-way deterministic sensitivity analysis, even after changing each parameter value within the predetermined range. A probabilistic sensitivity analysis with 10,000 simulations also revealed that HBV DNA monitoring is more cost-effective than Pro NAT in 96.8% of cases. Therefore, this study suggests that HBV DNA monitoring is an appropriate managing measure in Japan from a cost-effectiveness perspective.