Medical emergency teams (METs) are a widely implemented safety intervention, but controversy remains regarding their effectiveness. This study took place in Australia and New Zealand, where a prior randomized trial found no overall effect of METs on clinical outcomes. While most hospitals have implemented an MET, death rates from cardiac arrest appeared to decrease over the study period at all hospitals, regardless of whether an MET was in place. Despite the equivocal results of larger studies, implementation and development of METs will likely continue due to the improvement in clinical outcomes found in single-center studies and the positive opinion of nurses regarding the teams.