Recommendation for NHSScotland

Preliminary clinical evidence and economic modelling suggests there is potential for the Fungitell® Beta-D glucan (BDG) test to reduce empirical antifungal overuse with minimal direct cost impact, however, caution should be exercised in relation to the imperfect nature of the test and the potential risk involved in withholding or discontinuing empirical treatment in false negative cases.

Evidence from a small number of published studies indicates that BDG tests can be used as part of strategies to increase the rate of early discontinuation of empirical antifungal therapies in the adult critical care setting, although studies were not large enough to inform the safety of this approach. No evidence was identified on the use of BDG testing to withhold empirical antifungal therapy in this setting. Several relevant trials are in progress.

Economic modelling was conducted to inform the antifungal stewardship work of the Scottish Antimicrobial Prescribing Group. Diagnostic accuracy data were applied to clinical parameter estimates. Key findings were:

• A rapid turnaround Fungitell® testing strategy to inform withholding of empirical therapy results in a large reduction in unnecessary antifungal use due to the test’s high negative predictive value (NPV);
• The strategy is associated with an incremental cost resulting from the additional cost of testing which is not fully offset by the savings realised from the reduction in antifungal use;
• The strategy is associated with a minimal incremental cost or is potentially cost-saving, in settings with higher testing throughputs (maximising test kit utilisation) and where there is low infection prevalence and high empirical use, and where micafungin or amphotericin B are the most commonly used agents;
• In units where use of empirical therapy is less common costs may be significantly increased;
• There is a potential clinical risk linked to delaying treatment initiation in infected patients in whom empirical therapy is withheld based on false negative results, but this could not be properly quantified due to a lack of robust evidence;
• Indirect benefits such as reduced rates of serious adverse events and associated resource use and impact on quality of life, or the impact on antimicrobial resistance were not properly quantified due to a lack of robust data.

NHSScotland is required to consider the Scottish Health Technologies Group (SHTG) advice.

What were we asked to look at?

We were asked to examine the potential for the Beta-D glucan (BDG) test to reduce empirical antifungal overuse.  

Why is this important?

Overuse of empirical antifungal therapies in the critical care setting is a significant problem which exposes patients to potential harms of treatment from which they derive no benefit. Also, resistance to antifungal medications is emerging as a serious threat to global health.

Referred by

Scottish Antimicrobial Prescribing Group (SAPG)