Objectives To compare waiting time, treatment time, length of stay (LOS), patient satisfaction and distribution of waiting times over levels of urgency before and after the implementation of the Manchester Triage system (MTS) at an emergency department (ED).

Methods Before and after study, by means of timeline measurements and questionnaires on satisfaction in two consecutive patient series (n=1808). Questionnaires covered aspects of provision of information, opportunity given to explain problems, waiting time and sorting out the problem. After implementation of MTS, patients were triaged between 12:00 and 22:00. Subanalysis was performed on triaging and non-triaging; and between urgency levels.

Results Waiting time did not decrease after implementation of the MTS, however, treatment time and LOS were significantly longer. Total LOS did not differ. After implementation, waiting time was better distributed over urgency levels.

Furthermore, after implementation, patient satisfaction scored significantly lower on the provision of information and opportunity to explain their problems, however, waiting time and the feeling that their problem had been sorted out scored better. No significant differences were found between triaged and non-triaged patients. Although not significant, patients in the lower urgency levels seemed more satisfied than patients in the higher urgency levels.

Conclusions Implementing MTS on its own is not sufficient to improve efficiency and quality of EDs. More complex interventions including process redesigning that targets various groups of ED patients should be evaluated in the future by using rigorous research designs for quality improvement of EDs.