Kolstadbraaten KM, et al. - Using the institutional trauma registry (2007), researchers determined the long term incidence and potential risk factors of chronic pain after major trauma. Cases with injury Severity Score < 9, endotracheal intubation before or during admission, spinal cord lesion, known chronic drug or substance abuse, major surgery within 3 h after admission, were excluded. Six years post-injury, frequency and intensity of pain were inquired via a patient questionnaire. For the development of chronic pain, the identified risk factor was severity of the injury, whereas pain during initial hospital stay did not confer risk for chronic pain. Six y following injury, chronic pain was experienced by two thirds of the trauma patients and severe pain was experienced by one out of four. Opioids were prescribed initially to treat pain.