Early economic evaluation to identify the necessary test characteristics of a new typhoid test to be cost-effective in Ghana

Research output: Contribution to journalArticlepeer-review

Colleges, School and Institutes


Background: In Ghana, there are issues with the diagnosis of typhoid fever, these include: delays in diagnosis; concerns about the accuracy of current tests; and lack of availability. These issues highlight the need for the development of a rapid, accurate, and easily accessible diagnostic test. The aim of this study was to conduct an early economic analysis of a hypothetical rapid test for typhoid fever diagnosis in Ghana and identify the necessary characteristics of the test for it to be cost-effective in Ghana.

Methods: An early cost-utility analysis was conducted using a decision tree parameterized with secondary data sources, with reasonable assumptions made for unknown parameters. The patient population considered is individuals presenting with symptoms suggestive of typhoid fever at a healthcare facility in Ghana, a time horizon of 180 days and the Ghanaian national health service perspective were adopted for the analysis. Extensive sensitivity analysis was undertaken including headroom analysis.

Results: The results here show that for a hypothetical test to perform better than the existing test (Widal) in terms of QALYs gained and cost-effectiveness, it is necessary for it to have a high specificity (at least 70%) and should not be priced more than $4. The overall value of conducting research to reduce uncertainty (over 5yrs) is $3,287.

Conclusion: The analysis shows the potential for the hypothetical test to replace the Widal test and the market potential of developing a new test in the Ghanaian setting.

Key Points for Decision makers
•This study has wider implications for the early economic evaluation of diagnostic tests by contributing to a limited evidence base and identifying areas requiring further research.
•A high specificity (at least 70%) is a key test characteristic requirement for the hypothetical test (HT-test) to be able to improve current practice, and the HT-test is likely to improve current practice when used to replace the currently used test rather than use as triage or add-on.


Original languageEnglish
Early online date3 Aug 2019
Publication statusE-pub ahead of print - 3 Aug 2019


  • early economic evaluation, diagnostic test, headroom analysis, value of information analysis, typhoid fever, Ghana