Is the repeat worth it? Optimizing syndromic panel pathogen detection protocols.

Objective: The aim of the study was to compare the cost and clinical impact of repeating BioFire FilmArray gastrointestinal (GI) and respiratory (RP) panel assays with 3 vs 4 pathogen targets positive.

Method: We analyzed 12,027 GI and RP panels to evaluate our retesting policy, which retested panels with 3 or more detected pathogens (3-pathogen protocol) compared with the manufacturer's 4-pathogen (4-pathogen protocol) recommendation. We compared the retesting results, calculated the cost implications, and reviewed the clinical impact on antibiotic prescriptions and patient outcomes.

Results: Retesting with our 3-pathogen protocol revealed that 81% (39/48) of GI and 76% (26/34) of RP panels had identical results, whereas 19% (9/48) of GI and 24% (8/34) of RP panels showed discrepancies on retesting. The additional cost incurred by our protocol compared with the manufacturer's protocol was $9820.32. There was no evidence that our more stringent policy affected antibiotic prescription or clinical outcomes.

Conclusion: Our more stringent 3-pathogen protocol for retesting panels did not improve patient management compared with the manufacturer's 4-pathogen protocol but resulted in unnecessary costs and increased the risk of depleting testing kits during supply shortages. Consequently, we adopted the manufacturer's suggestions, highlighting the need to balance clinical rigor with cost-effectiveness in laboratory testing protocols.