Seasonal variation in trauma admissions to a level III trauma unit over 10 years

Major trauma centres have improved morbidity and mortality for moderate and severely injured patients. Less injured patients may be treated in facilities less resourced for trauma care. In these units, understanding the variations in injury presentation and treatment over time allows service delivery to be tailored to demand. This study set out to describe seasonal variations in trauma over a 10-year period at a level III trauma unit.

Patient demographics, admission frequency, site of injury, season of admission, management, complications, onward transfers, and length of stay were extracted on consecutive patients admitted with traumatic injuries between January 2009 and December 2018 and recorded on a prospectively maintained database. Analysis was undertaken to determine if there were reproducible patterns in trauma presentation across seasons, based on the patient's age and gender, type of injury, management and length of stay.

There were 13,007 'first admissions' over 10 years, with a mean (SD) age of 55.6 (27.7) years. Admissions were higher in summer (27%) and lower in winter (23.6%) and patients were on average younger in the summer (52.8 years) and older in winter (59.2 years). The proportion of female and male patients remained relatively constant across seasons (CV=6% and 8%, respectively). There was seasonal variation in the incidence of forearm (36%) elbow (19%), and multi-sites injuries (17%) compared with hip and wrist injuries (CV=5% for both). A lower proportion of patients underwent operations in summer (72%) compared with other seasons with winter having the highest at 77%. More patients aged less than 60 years stayed in hospital during winter than summer (13.2% vs. 11.6-12.4%) although often for a day. Patients aged 60 years stayed longer in spring and winter.

The results of this study demonstrate trends in the admission and management of trauma patients to a level III trauma unit. Some of the patterns in admission, treatment and length of stay had not been identified previously. The results can be used to enhance patient care and minimise health care costs by reducing unwarranted variations and enabling service delivery to match the demand in all trauma units.