Bedside rapid flu test and zanamivir prescription in healthy working adults: a cost-benefit analysis.

BACKGROUND: Zanamivir, a neuraminidase inhibitor, reduces the number of days of illness in influenza-positive patients. New bedside rapid flu tests (RFT) should increase the number of influenza-positive patients whom receive zanamivir appropriately.
OBJECTIVE: To estimate the economic effects of implementing RFT and zanamivir among unvaccinated healthy working adults who consult within 2 days of the onset of influenza-like symptoms.
METHODS: We constructed a decision tree to perform a cost-benefit analysis from a societal perspective. Clinical outcome, i.e. number of influenza days averted, and societal costs were compared for three strategies: RFT and conditional zanamivir prescription;systematic zanamivir prescription; and no zanamivir. A two-way sensitivity analysis was performed including the proportion of influenza-positive patients.
RESULTS: During influenza epidemics, systematic zanamivir prescription provided the best health outcome (0.81 influenza days averted) and minimised societal costs (reduced by 29.80 US dollars per person compared with no zanamivir; 1999 values). RFT with conditional zanamivir averted 0.65 influenza days and saved 14.40 US dollars per person. When the proportion of influenza-positive patients was under 39%, the no zanamivir strategy yielded the greatest societal savings; otherwise, systematic zanamivir was the dominant strategy. Medical costs associated with no zanamivir were 88.70 US dollars per patient consulting with influenza-like illness, and increased to 125.50 US dollars with systematic zanamivir and to 127.60 US dollars with RFT and conditional zanamivir.
CONCLUSIONS: Due to poor sensitivity of current RFT, systematic zanamivir prescription without RFT for unvaccinated healthy working adults should be recommended during influenza epidemics.