Abstract

Background: Ambulance services are critical in pre-hospital emergency care, with air and ground transport differing in speed, resources, and outcomes.
Objective: This study evaluates survival and mortality outcomes of severely injured patients transported via air versus ground ambulance from remote locations to medical facilities.
Methods: This retrospective cohort study analyzed data from all air rescue centers collaborating with national emergency services in Iran (2017-2018). The study population included 1,250 patients transferred by air ambulance and 5,650 by ground ambulance (Tehran emergency database). Descriptive statistics summarized demographic and clinical characteristics. Propensity score matching adjusted for age, sex, diagnosis, severity, and distance. Odds ratios (OR) with 95% confidence intervals (CI) assessed mortality outcomes, with ground transport as the reference (OR < 1 indicating lower mortality odds for air transport), using logistic regression (SPSS v23, p < 0.05).
Results: Of 6,900 patients, 1,250 (18.2%) were air-transported (64.3% male, median age 57 years, IQR 50-65). Air transport was used for 33.5% central nervous system (CNS) disorders, 24.9% cardiovascular diseases, and 16.2% traumatic injuries. Air-transported patients had higher trauma severity (mean ISS 18.2 vs. 14.5 for ground) and shock prevalence (18.3% vs. 14.8%). Air transport was associated with lower mortality (AOR 0.61, 95% CI 0.48-0.77, p < 0.001) and higher survival in 6-30 min intervals (AOR 1.46-1.80). Median transfer time was 1.3 hr (IQR 1.0-1.6) for air vs. 1.9 hr (IQR 1.5-2.3) for ground.
Conclusion: Air transport is associated with lower mortality and higher survival in time-sensitive emergencies, particularly for CNS, cardiovascular, and trauma cases.

Key words: Air ambulance, Ground ambulance, Emergency medical services, Pre-hospital care, Clinical outcomes.