The landmark paper discussed in this chapter, published in 2002 by Dolin et al., examines the incidence of moderate-to-severe pain and severe pain after major surgery with three analgesic techniques: intramuscular analgesia, patient-controlled analgesia, and epidural analgesia. Up until 1990, intramuscular morphine was the main form of post-operative pain control, with patient-controlled analgesia and epidural analgesia as relatively new techniques. The authors found that the mean incidence of moderate-to-severe pain was more common with intramuscular analgesia (67%) than with patient-controlled analgesia (36%) or epidural analgesia (21%), while the incidence of severe pain was similar, with the incidence of pain with intramuscular analgesia being highest (29%), followed by that associated with patient-controlled analgesia (10%) and epidural (8%). Of note, only patient-controlled analgesia and epidural achieved the Audit Commission’s 1997 standard of no more than 20% of patients experiencing severe pain, while no technique reached their 2002 standard of less than 5%.