Multiplex PCR point of care testing versus routine, laboratory-based testing in the treatment of adults with respiratory tract infections: a quasi-randomised study assessing impact on length of stay and antimicrobial use

Andrews, Denise; Chetty, Yumela; Cooper, Ben S.; Virk, Manjinder; Glass, Stephen K; Letters, Andrew; Kelly, Philip A.; Sudhanva, Malur; Jeyaratnam, Dakshika

Seventy-five percent of the POC results were negative, providing no information about the aetiology of the infection or the predicted clinical course. Negative results would not be expected to expedite discharge or antibiotic cessation, the main outcomes under consideration here. A paediatric observational study found that patients with a positive respiratory virus PCR result had a 42% shorter duration of intravenous antibiotics [24] . A retrospective study noted a reduced length of stay in children with a positive FilmArray® result reported within 4 h, not seen with negative tests [25] . The reduced time to detection of influenza with laboratorybased FilmArray® was associated with significantly lower odds ratios for admission, length of stay, duration of antibiotics and chest X-rays when compared to positive routine tests in a retrospective study of adults [26] . A randomised trial noted that patients with positive Fil-mArray® POC results received shorter courses of antibiotics and had shorter hospital stays than those with negative POC results [21] . Our 20-24% positive yield may be because our study was seasonally limited and extended in to the summer months. Further, we did not record the types of RTI, which may have resulted in this lower than expected percentage. Another UK, adult study between September 2012 and February 2014 identified viruses in 30% of patients with lower RTI [27] .