Introduction: Resource allocation planning (RAP) for emergency medical services (EMS) systems determines optimal resources for patient needs in order to minimize morbidity and mortality. The British Columbia Emergency Health Services developed a new RAP using an evidenced informed methodology, statistical analysis of outcomes and with further clinical input from EMS physicians, paramedics and allied EMS providers. The revised RAP was implemented on a pan provincial basis in fall of 2013. It is unknown how the modifications will affect outcomes of EMS cases. Population-based analysis was used to determine the effect of a comprehensive RAP changes by comparing 24-hour mortality before and after province-wide implementation of the revised RAP. Methods: The primary outcome, 24-hour mortality, was obtained through linked provincial health administrative data. All adult cases with evaluable outcome data were included in the analysis. A pre and post methodology was used to evaluate the effect of post-RAP revision (post-RAP-revision) on 24-hour mortality compared to pre-RAP revision (pre-RAP-revision). Multivariable logistic regression was used to adjust for variations in other significant factors associated with 24-hour mortality. The interrupted time series (ITS) estimated any immediate changes in the level or trend of outcome after the start of the revised RAP implementation (fall of 2013), while simultaneously controlling for pre-existing trends. Results: The cohort is comprised of 562,546 cases (April 2012 March 2015). In the multivariate model, adjusted for age, sex, urban/metro region, season, day hour, and MPDS determinant, the probability of dying within 24 hours of EMS call was 7% lower in the post-RAP-revision cohort (OR=0.936; 95% CI: 0.886 - 0.989; P=0.018). A sub-group analysis of immediately life-threatening cases demonstrated similar effect (OR=0.890; 95% CI: 0.808 - 0.981; P=0.019) Conclusion: Our results demonstrate that a comprehensive, evidence informed reconstruction of a provincial EMS RAP is feasible. Despite considerable change in crew level response and resource allocation, there was significant decrease in 24 hour mortality in a large pan-provincial population based patient cohort.