Abstract: Explains the need for nurse-led Patient-at-Risk-Teams(PART) to prevent unnecessary ICU admissions. Investigates which nurse allocation policy between PART and ICU would result in the best outcomes for patients and hospitals. Provides econometric models to estimate the impact of critical care nurses on hospital length of stay. Proposes queueing and simulation models to obtain the optimal nurse allocation policy for minimising the ICU mortality rate. Validates proposed models at Middlemore Hospital from 2015 to 2016. Estimates the financial and mortality impact of allocating another nurse to PART per shift.