Impact of multiplex respiratory virus testing on antimicrobial consumption in adults in acute care: a randomized clinical trial.

Objectives: Inappropriate use of antibiotics is associated with development of antimicrobial resistance. In respiratory infections it is often difficult to differentiate between viral and bacterial infections, and empirical treatment is common. Enhanced viral testing is expected to clarify clinical decision-making and reduce the prescription of antibacterial agents, but the impact of such information on patient care is unclear.

Methods: We conducted a (1:1) randomized controlled clinical trial involving 998 adults with respiratory symptoms, fever, chest pain or poor general condition in the emergency unit of a tertiary hospital. Multiplex PCR results for 496 patients were available in 24 hours (intervention group) and those for the remaining 502 patients were available in 7 days (control group). Our primary outcome measures were the duration of hospitalization and the consumption of antibiotics within 30 days of enrolment.

Results: In all, 841 of 998 (84%) patients had respiratory symptoms at study entry. A respiratory virus was detected in 175 (17.5%). The mean duration of hospitalization was 4.2 days (SD 5.4) in the intervention group and 4.1 days (SD 4.9) in the control group (difference 0.1, 95% CI -0.5 to 0.6, p 0.810). The mean days on antibiotics were 11.3 days (SD 12.6) in the intervention group and 10.4 days (SD 11.4) in the control group (difference 0.9, 95% CI -0.6 to 2.4, p 0.235).

Conclusions: Multiplex PCR testing for respiratory viruses with results available within 24 hours did not reduce the consumption of bacterial antibiotics or the length of hospital stay in adults presenting with respiratory symptoms, fever, chest pain or reduced general condition in acute care.