Incident location at home and emergency medical services on-scene time for older adults in Japan: a population-based cross-sectional study.

Abstract

Background: As population aging increases the demand for emergency medical services (EMS), reducing prehospital time has become crucial for improving patient outcomes and operational efficiency. Accessible housing environments may facilitate patient transportation and reduce on-scene time (interval between ambulance arrival and departure from the scene), but evidence is scarce. This study examined the associations between incident locations at home and EMS on-scene time among older adults in Japan.

Methods: This population-based cross-sectional study analyzed 26,058 people aged ≥ 65 years transported from their homes to hospitals by the Higashi-Hiroshima Fire Department's ambulances between January 2016 and December 2024. We examined the associations between two exposure variables (floor level and in-home location) and on-scene time using generalized linear models with gamma distribution and log-link function. Adjusted mean ratios (aMRs) and 95% confidence intervals (CIs) were calculated. Then, a correspondence analysis using text data from the ambulance dispatch records was conducted to generate further hypotheses regarding the factors characterizing each in-home location.

Results: The median EMS on-scene time was 16 min (interquartile range: 13-21). Higher floors were significantly associated with progressively longer on-scene times. When compared with living rooms, corridors (aMR: 0.95, 95% CI: 0.93-0.97) and gardens (aMR: 0.95, 95% CI: 0.93-0.98) had significantly shorter on-scene times. In contrast, toilets (aMR: 1.08, 95% CI: 1.04-1.12), bathrooms (aMR: 1.09, 95% CI: 1.05-1.13), and kitchens (aMR: 1.06, 95% CI: 1.03-1.10) had significantly longer on-scene times. Correspondence analysis showed that garden and other locations were positioned at the "exogenous" pole along the horizontal axis (representing type of injury or disease). The toilet, bathroom, and kitchen, which were associated with longer on-scene times, were positioned toward the "loss of consciousness" pole along the vertical axis (representing level of consciousness).

Conclusions: Higher floors and confined areas (toilets and bathrooms) were associated with longer on-scene time. Future studies are invited to examine the effect of patients' consciousness levels to ensure that paramedics can rapidly reach and transport emergency patients regardless of location.