<qa>  What is the goal of phase III?Objectives: The goal of phase III is to evaluate the effectiveness and safety of an active strategy to implement the Canadian C-Spine Rule into physician practice. Specific objectives are to: 1 Determine clinical impact by comparing the intervention and control sites for: a C-spine radiography rates, b Missed fractures, c Serious adverse outcomes, d Length of stay in ED, and e Patient satisfaction; 2 Determine sustainability of the impact; 3 Evaluate performance of the Canadian C-Spine Rule, with regards to: a Accuracy, b Physician accuracy in interpretation, and c Physician comfort and compliance with use; 4 Conduct an economic evaluation to determine the potential for cost savings with widespread implementation. 