title: Incidence of liver trauma and relative risk factors for mortality: a population-based study.
abstract: BACKGROUND
  Liver trauma is the main cause of death arising from blunt abdominal injury. Nonoperative management (NOM) has been advocated to be a safe option for stable patients who have suffered liver trauma. This study used a population-based dataset to illustrate the incidence of liver trauma, its various causes and treatment, and outcomes.
  
  
  METHODS
  Information about all patients with any ICD-9-CM coded as liver injury was retrieved as part of a claims dataset for the years 2007 and 2008 from the database maintained in the Bureau of National Health Insurance in Taiwan. Thereafter, statistical analyses were conducted to discover the incidence, mortality rate, percentage of patients receiving NOM, and the association between variables such as age, gender, injury mechanisms, associated injuries, and outcome.
  
  
  RESULTS
  A total of 3196 liver trauma patients were admitted in 2007 and 2008, resulting in 264 deaths. The incidence rate is 13.9/100,000 population. The highest incidence rate was in the age 15-24 years group, 25.9/100,000 population; the highest mortality rate was in the age 75-84 years group, 2.1/100,000 population. Additionally, rural residents possessed a higher incidence and mortality rate than urban residents (15.9/100,000 population vs. 12.2/100,000 population and 1.4/100,000 population vs. 1.0/100,000 population). By using logistic regression, the mortality rate was significantly higher in the groups with patients aged >64 years, renal failure or liver cirrhosis, with head or chest, or other abdominal injury. If a patient received a hepatic or abdominal operation, this was retrospectively found to be associated with increased mortality risk (4.731 times, p < 0.001 and 4.311 times, p < 0.001, respectively); however, the characteristics of the treating hospitals did not influence the mortality rate. Patients whose monthly income was >US$660 were found to have a higher mortality risk (2.209 times, p < 0.001).
  
  
  CONCLUSIONS
  The overall incidence rate of liver trauma was higher in the younger age group and in rural residents. A higher risk of mortality was found in the age > 64 years group, pedestrians hit in motor-vehicle accidents, renal failure or liver cirrhosis, with head or chest, or other abdominal injury.
authors.affiliation: Department of Surgery, National Yang-Ming Medical University Hospital, I-lan, Taiwan, ROC.
authors.forename: Li-Chien
authors.initials: LC
authors.lastname: Chien
authors.forename: Su-Shun
authors.initials: SS
authors.lastname: Lo
authors.forename: Shih-Yu
authors.initials: SY
authors.lastname: Yeh
mesh_terms: D000007:Abdominal Injuries / Q000453:epidemiology / Q000401:mortality; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D015994:Incidence; D008099:Liver / Q000293:injuries*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
keywords: incidence; liver trauma; mortality; nonoperative management; rural–urban