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UBC Theses and Dissertations

The effect of implementing a Modified Early Warning Score on patient outcomes in an inpatient cardiology ward Grespan, Patricia


Background: The Modified Early Warning System (MEWS) was implemented on an in-patient cardiology unit with the aim of improving patient safety, increasing efficiency of transfer of unstable patients to critical care, more timely physician interventions, decreasing code blue calls, and improved communication between nurses and physicians. Objective: To investigate the association between the implementation of a Modified Early Warning System (MEWS) on a cardiology unit with patient outcomes: proportion of code blue calls and in-hospital mortality and mean lengths of hospital stay. Method: This study used a quasi-experimental design. Data sources included: discharge separation files and archived cardiac arrest data. Interrupted time series analysis was used to compare trends before and after MEWS implementation. Results: Results from the generalized least-squares model reveal that there was an increase of 1.04 in the code blue rate following the implementation of the MEWS; however, this was not statistically significant (95% CI -0.0158-2.0991, p = 0.0671). There was a sustained significant increase in the trend of 0.33 of code blues called per month (95% CI 0.1932-0.4658, p = 0.0001). There was a decrease of 0.05 (95% CI -1.2328-1.3328, p = 0.94) of in-hospital mortality and a decrease of the in-hospital mortality trend of 0.16 per month (95% CI -0.0207-0.3374, p = 0.098) following the implementation of the MEWS, however, neither were statistically significant. A decrease of 0.07 in the mean length of stay (95% CI -1.6784-1.5322, p = 0.93) and a decrease in the trend of about 0.18 per month in the mean length of stay (95% CI -0.0429-0.4052, p = 0.13) following the implementation of the MEWS was found, but neither was statistically significant. Conclusion: This study provides evidence that the use of a MEWS may not be associated with patient outcomes. Recommendations for future research and implications to nursing practice are addressed. Interrupted time series analysis was a strong study design for examining the use of the MEWS and patient outcomes; It is a method that should be utilized in nursing research.

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