Evidence on Initial Diagnostic Interventions
We identified eight systematic reviews (five with meta-analysis) of prospective studies24-26,28,29,53,59,86,91 and seven prospective studies35,37,40,51,54,79,87 evaluating routine initial imaging (i.e. X-ray or CT). We also identified two case series22,38 evaluating routine pre-operative blood tests in American Society of Anaesthesiologist (ASA) grade I patients. Studies reported injuries would have been missed in ≤ 2.0% of patients who were negative on a validated clinical decision rule for spine, knee or ankle injury, or had a negative physical exam for pelvic injury (Table 2).25,35,51,86 One prospective study in patients > 65 years old37 reported 2.0% (95% CI 0.1 to 12.0%) of clinically relevant missed injuries (e.g. displaced fractures, subluxation) when the National Emergency X-Radiography Utilization Study (NEXUS) decision rule was used. X-rays to detect wrist injury in patients negative on a validated clinical decision rule or physical exam were associated with more divergent findings with one prospective study reporting 0% missed injuries (range: 0 to 11.4)54 and another 10% (range 1.0 to 19.0).87 Preoperative blood tests in ASA grade I patients requiring minor orthopaedic surgery did not lead to changes in patient management.22,38