Emergency Medical Service Response Times and Fatal Fall Injuries Among US Older Adults: Analysis of the 2015 – 2020 National Trauma Data Bank

Background Falls are the leading injury-related cause of death among older adults but rapid emergency care may reduce fatal complications. To estimate the strength of the association between EMS response times and fatal fall injuries among older adults and measure how this association differs by sex. Methods For this retrospective cohort study, we pooled 2015 – 2020 data from the National Trauma Data Bank on patients 65 years and older with fall injuries transferred to U.S. trauma centers (N=705,491). The main outcome was fatal fall injuries. The main predictor was EMS response time, measured as continuous and four-level categorical variables (multiples of the standard nine-minute benchmark). Age, sex, race/ethnicity, and diagnoses of COPD, diabetes, and hypertension were covariables. We performed a mixed-effect multivariable logistic regression, using the trauma center designation level as a random effect variable, and EMS response time and mortality as fixed effect variables. We report the unadjusted and adjusted odds ratio (AOR) plus 95% confidence intervals (CI). We also created an interaction model comprising of response time and sex and reported the predicted probabilities (plus 95% CI) of fatal fall injury by sex and response time categories. Results The case fatality rate of fatal fall injuries among adults 65 years and older was 4.4%. The median (Q1, Q3) EMS response time was 8 minutes (5.0, 13.0), with 60% of patients experiencing the nine-minute benchmark. In the adjusted model, a minute delay in EMS response time was associated with a 1% increased odds of fatal fall injury (AOR: 1.01; 95% CI: 1.01 – 1.01). Older adults who experienced a response time between 18 and 27 minutes, and more than 27 minutes had 1.33 (95% CI: 1.28 - 1.39), and 1.41 (95% CI: 1.35 - 1.47) times the odds of fatal fall injuries. The predicted probabilities of male and female fatal fall injuries were 5.1% (95% CI: 3.51 – 6.75) and 2.4% (95% CI: 1.64 – 3.23), respectively. Conclusion Delayed EMS response time, especially when above twice the standard benchmark, is associated with increased odds of fatal fall injuries among older adults. Question What is the association between EMS response time and fatal fall injuries among US older adults? Findings In this retrospective cohort analysis, delay in EMS response time was associated with fatal fall injury in a dose-response pattern among male and female older adults. Meaning Strengthening the EMS infrastructure may improve outcomes from fatal fall injuries among older adults. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The New York University Langone Health Institutional Review Board waived ethical approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors