<qa>  What is the between-group difference in before-after improvement in pain relief at 60 minutes?RESEARCH QUESTION: In adult ED patients in whom the attending ED physician has decided to administer intravenous opiates, what is the between-group difference in before-after improvement in pain relief at 60 minutes in patients who are randomized to receive either weight-based IV morphine 0.1mgkg or weight-based IV morphine 0.15 mgkg? 