title: Temporal patterns of death after trauma: evaluation of circadian, diurnal, periodical and seasonal trends in 260 fatal injuries.
abstract: BACKGROUND
  Temporal patterns of trauma deaths may indicate potential for prevention or systems improvement, but have been poorly investigated in the Scandinavian trauma population. This study examines patterns in trauma deaths to the occurrence in hour and time of the day, day and time in the week, and month and season.
  
  
  METHODS
  Investigation of the temporal patterns of death in 260 fatalities undergoing autopsy. Time of death were explored according to time of the day (hour; day/night), time of the week (day of week; weekday/weekend) and time of the year (month; season) and analyzed for difference in gender, age, injury type and severity, and mechanisms of injury and death.
  
  
  RESULTS
  A total of 260 trauma deaths were included, of which 125 (48%) died in hospital and 194 (75%) were male. No particular peak-hour of the day when deaths occurred was found. One-third of deaths occurred during weekends. For inhospital deaths during weekends, significantly more patients had respiratory distress (RR > 20 or < 16 in 72.5% for weekends and 47.0% for weekdays; p = 0.008) and hypotension (SBP < 90 mmHg in 61% vs 40%; p = 0.048) during weekends. Deaths occurred with some monthly variance demonstrated with two monthly peaks in February/March and July/August, respectively. Overall, no statistically different seasonal differences in the occurrence of traumatic deaths, nor any differences in cause of death, type or severity of injury, nor in physiological parameters was found. However, a higher number of inhospital deaths presented with reduced consciousness level (GCS < 8) and severe head injuries (AIS-head = 4) during spring and summer (P = 0.045, chi-square for trend) compared to winter and fall.
  
  
  CONCLUSIONS
  Trauma deaths in a Scandinavian population did not demonstrate statistically significant differences in overall circadian, weekly or seasonal patterns of trauma death occurrence. However, the impact of fatal head injuries during spring and summer warrants further investigation.
authors.affiliation: Department of Surgery, Stavanger University Hospital, Stavanger, Norway. ksoreide@mac.com
authors.forename: K
authors.initials: K
authors.lastname: Søreide
mesh_terms: D000059:Accidents / Q000706:statistics & numerical data; D000328:Adult; D000368:Aged; D002423:Cause of Death; D016000:Cluster Analysis; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway; D010507:Periodicity; D012189:Retrospective Studies; D014947:Wounds and Injuries / Q000453:epidemiology*; D055815:Young Adult