A Systematic Review of the Relationship Between Ambulant Status and the Need for a Lights-and-Siren Ambulance Response to Crashes

Introduction: Motor vehicle crashes (MVCs) can result in life-threatening injuries, and ambulances are therefore often dispatched at the highest priority response of lights­ and-siren (L&S). However, assigning L&S ambulance response based on type of incident alone may result in over-triage, meaning that the patient’s condition did not warrant L&S ambulance response. Potentially, the ambulatory status of the MVC patient at the scene (i.e., whether they can walk) could help inform the ambulance dispatch priority, given that ambulation reflects both a person’s physical ability to walk and their conscious state. The objective of this systematic review is to examine published studies to determine whether ambulatory status of those involved in an MVC can predict the need for L&S ambulance response. Methods: A systematic review of the literature was conducted. The following databases were searched: Ovid MEDLINE, Ovid EMBASE, EBSCO CINAHL, Scopus, Cochrane Library and grey literature from inception until April 2, 2019, were searched. Studies meeting the following criteria were included: 1) comparative study; 2) patients involved directly in an MVC; 3) ambulatory status reported as an exposure; and 4) the need for L&S ambulance response reported as an outcome. Studies were assessed for risk of bias. Results: The search strategy yielded 2,856 unique citations, including one study that directly addressed the review question. This study found that non-ambulation was a strong predictor of the need for L&S ambulance response (OR 0.13; 95% Cl 0.07-0.24) based on field triage guidelines. Conclusion: There was insufficient evidence to reach a conclusion regarding the utility of ambulatory status as an indicator of the need for L&S ambulance response. Further research in this field is required