[Impact of weather, time of day and season on the admission and outcome of major trauma patients]

Abstract

Background and objectives: The potential association of external factors such as time of day, lunar phases or specific weather conditions on the daily management and outcome of trauma emergencies remains under debate. We undertook this trauma centre investigation to detect possible worthwhile factors of influence in order to optimize the organizational structure of trauma admissions.

Materials and methods: Retrospective cohort analysis over the years 2010-2013, including all emergency trauma admissions with a new injury severity score (NISS) ≥8 (major trauma) treated in a teaching hospital in the lowland of Switzerland (uni- and multivariable analysis; p < 0.05).

Results: During the study period, 1178 major trauma patients were admitted to the hospital. The mean age of trauma victims was 53 ± 23 and the average ISS was 14 ± 8. More patients arrived within the summer months than during the rest of the year (p < 0.001). Higher energy trauma was found to correlate with higher daytime temperature, longer duration of sunshine (each p < 0.001), and change in weather conditions (p = 0.008). In contrast, snowfall and lunar phases did not demonstrate any association with the number or characteristics of trauma admissions. Multivariable analysis demonstrated that altogether longer sunshine, higher minimum daytime temperature and lower air humidity, compared to the previous day, accounted for 31 % of major trauma admissions. We could not find any impact of the investigated external factors on the outcome of patients.

Conclusions: The study shows a significant relationship between specific weather conditions, such as higher daytime temperature or change in circulation, and the admission of major trauma patients. Due to the small effect in our setting, our results do not implicate any according change in the management of resources. Nevertheless, for hospitals in other geographic or more exposed weather regions, such effects could indeed be relevant and therefore should be tested.

Keywords: Epidemiology; Outcome; Patient admission; Trauma; Weather.