Lack of effect of shorter turnaround time of microbiological procedures on clinical outcomes: a randomised controlled trial among hospitalised patients in the Netherlands

Abstract

Shortening the turnaround time of microbiological procedures was associated with an improved clinical outcome in two studies performed in the USA. To study the clinical impact of a shortened turnaround time in a northwest European setting in which an automated system was used for bacterial identification and susceptibility testing, a single-blind, prospective, randomised controlled trial was conducted in a hospital in the Netherlands. All hospitalised patients with a bacterial infection confirmed by culture were randomly assigned to a control (conventional) group or an intervention (rapid) group. Overnight methods were used for identification and susceptibility testing in the control group, while the Vitek 2 system (bioMerieux, Marcy l'Etoile, France) was used in the rapid group. In each of three consecutive study periods, accelerating factors were added progressively to the laboratory workflow of the rapid group to increase same-day reporting, whereas methods remained identical in the conventional group. The turnaround time of the microbiological cycle using the Vitek 2 system as compared to conventional methods was studied and the clinical impact of a shortened turnaround time assessed in terms of mortality, morbidity, and cost. For the rapid groups, the turnaround time was significantly shorter for oral reporting of final susceptibility results in all three study periods and for reporting on paper in the third study period. There was no significant difference between groups in any of the clinical impact variables. Vitek 2 results were available for reporting significantly earlier as compared to conventional testing. For the overall patient group in our hospital setting, however, this had no clinical impact.