Clinical and cost implications of Biofire FilmArray® meningitis / encephalitis panel testing: a systematic review

Background: Meningitis and encephalitis are diseases with high case fatality rates and serious long-term sequalae. A significant percentage do not receive an aetiological diagnosis, in part due to limitations of conventional testing methods. The Biofire FilmArray (R) Meningitis / Encephalitis Panel (MEP) is the first commercially approved multiplex PCR panel for diagnosis of infectious meningoencephalitis. It provides rapid results and has the potential to reduce empiric antimicrobial use and length of hospitalisation when compared to conventional testing. Methods: We conducted a systematic review to evaluate the impact of MEP implementation by searching the Medline and Embase databases. The outcomes of interest were duration of acyclovir treatment, duration of antimicrobials, length of stay and healthcare cost. Results: A total of 23 studies satisfied the inclusion criteria, the majority of which were retrospective studies comparing cohorts before and after MEP implementation. The included studies were very heterogenous, with variation in MEP implementation strategies, standard of care diagnostics and study populations. MEP testing resulted in reduction in acyclovir use in 75 % of studies with an average reduction of 39 h (range 11-144 h). Antimicrobial use and length of stay was reduced in 44 % and 40 % of studies respectively. Five studies looked at healthcare costs, variably described between studies as hospitalisation, antimicrobial and microbiology costs. Total hospitalisation cost was reduced in 1 study and unchanged in 2 studies. Conclusion: Whilst MEP implementation reduces acyclovir usage in patients evaluated for ME, the benefits in terms of antibiotic use, and length of stay are variable and likely depend on the study population, implementation strategy and standard of care testing available in each institution.