Air Medical Transport for Acute Ischemic Stroke Patients: A Retrospective Cohort Study of National Trends Over an 8-Year Period

Air Med J. 2023 Nov-Dec;42(6):423-428. doi: 10.1016/j.amj.2023.06.007. Epub 2023 Jul 7.

Abstract

Objective: Optimal management of ischemic stroke is time dependent. An understanding of patterns of air medical transport may identify disparities that could affect patient care.

Methods: In this 8-year (2007-2014) observational, retrospective, cohort study, we abstracted a 20% national sample of Medicare data from patients ≥ 66 years of age hospitalized with a primary diagnosis of acute ischemic stroke who presented to the emergency department by ambulance (air or ground).

Results: Among 149,751 hospitalized stroke patients who arrived by ambulance, the mean age was 81.6 years (standard deviation = 8.0 years), 62.1% were female (n = 93,007), and 86.3% were White (n = 129,268). Of these, 5,534 patients (3.7%) used any form of air ambulance. Air ambulance use (2007: 2.5%, 2014: 4.9%; P < .001) and arrival at certified stroke centers (2007: 40.3%, 2014: 63.2%; P < .001) increased over time. Air ambulance use was less likely among older patients (76-85 years and >85 years vs. 66-75 years; odds ratio [OR] = 0.68; 95% confidence interval [CI], 0.64-0.72 and OR = 0.34; 95% CI, 0.32-0.37, respectively) and all racial minorities except American Natives (OR = 2.07; 95% CI, 1.57-2.73) and more likely among sicker patients (Charlson Comorbidity Index ≥ 2 vs. 1, OR = 1.23; 95% CI, 1.09-1.38) and rural residents (OR = 1.34; 95% CI, 1.09-1.64). After adjustment for covariates, air ambulance use was associated with higher odds of thrombolysis (adjusted OR = 2.57; 95% CI, 2.38-2.79).

Conclusion: Air ambulance use is independently associated with increased thrombolysis use for stroke, but disparities exist in both air ambulance and thrombolysis use. Further research into underlying causes for these disparities would be beneficial for systems and public health-based interventions for improving outcomes for ischemic stroke.

Publication types

  • Observational Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • Female
  • Humans
  • Ischemic Stroke*
  • Male
  • Medicare
  • Retrospective Studies
  • Stroke* / epidemiology
  • Stroke* / therapy
  • United States / epidemiology