Removing modifications to the New Zealand Early Warning Score- does ethnicity matter? A multimethod research design.

Background: Previous research on a modified New Zealand Early Warning Score (M-NZEWS) used in predominately medical ward patients identified removing the modifications would significantly reduce the number of M-NZEWSs triggering the medical emergency team (MET), particularly in Māori patients.

Aim: To firstly, explore the impact of removing the modifications from the M-NZEWS on medical and surgical ward patients' early warning score MET triggers and secondly, determine if the M-NZEWS MET triggers resulted in MET activations and if the MET activations were a result of M-NZEWS MET triggers.

Method: The study used a multimethod research design. Phase one analysed ward electronic vital sign data and phase two analysed MET and critical care outreach data from the critical care outreach data base.

Results: Data of 353 patients and 1004 M-NZEWS MET triggers were analysed. Removing the modifications would result in 26.9% fewer patients with MET triggers, with the biggest impact on Māori. Only 45.8% of M-NZEWS MET triggers were escalated to the MET with 58.9% escalated to critical care outreach. Review of the MET activations identified only 59.2% had M-NZEWSs triggering the MET recorded in the electronic vital sign system; however the critical care outreach data base identified most of the MET activations were because of M-NZEWS MET triggers.

Conclusion: Removing the modifications would significantly reduce the number of MET triggers, particularly in Māori patients. Analysing solely electronic vital sign data may not reflect the number of medical emergency team triggers or activations.