Casey et al. International Journal of Emergency Medicine 2012, 5:28 http://www.intjem.com/content/5/1/28 but not definitively identified in the medical record, then it was recorded as no injury. If multi-system injury was sustained all locations and types of injury were recorded. Classification of injury type was based on review of complete patient medical records, including history, phys- ical exam, definitive diagnoses, radiologic studies, intra- operative examination, and pathological examination. Outcome measures Mortality was defined as an injury-related death prior to arrival to the hospital, death prior to hospital admission from the emergency department or death during hospitalization. The severity of injury was determined using the WHO Injury Surveillance Guideline coding recommendations: (1) no apparent injury; (2) minor or superficial injury; (3) moderate, requiring some skilled treatment (e.g., sutures); (4) severe, requiring intensive medical/surgical management [8]. The definition of a sur- gical intervention included fracture reductions, laceration repairs and all procedures requiring intervention in the operating theater. Duration of hospitalization was mea- sured in days and defined as time spent in the hospital, from evaluation in the casualty department to the day of discharge from the hospital or expiration day. Patients observed in the hospital for less than 24 h or who expired in less than 24 h were considered to have a 1-day length of hospitalization. Patients who were evaluated in the casualty department and then discharged to home were considered to have 0 days of hospitalization. Disposition from the emergency department was categorized as trea- ted and released, admission to the hospital, transfer to another facility or death in the emergency department. Statistical analysis Descriptive data from the 998 available complete patient records were analyzed using the R Environment for Statis- tical Computing and Graphics [11]. Means and standard deviations (SD) were used to describe continuous vari- ables. Frequencies and proportions were used to describe categorical variables with confidence intervals of the pro- portions determined. Inter-rater reliability of the data col- lection tool was evaluated using Cohen’s kappa coefficient. Correlates of mortality and severity of illness were reported as crude odds ratios and calculated using logistic regression in JMPW Pro 9.0. Results During a 7-month time period, dating 1 January 2010 to 31 July 2010, 10,622 patients presented to the emergency department at KCMC for evaluation and treatment. One thousand two hundred twenty-four patients were identi- fied from the emergency department logbook with an injury-related diagnosis, representing 11.5% of all visits. Of the 1,224 patients initially identified, 1,003 medical Page 3 of 7 charts were located. Two hundred twenty-six patients were not included because of missing medical records or incorrectly documented medical record numbers. Nine hundred ninety-eight medical records were adequately complete for data analysis (Figure 1). Based on the emer- gency department logbook, the patients with missing medical records were slightly older, with an average age of 40.1 years. Otherwise, they were similar, with 72.7% males, 26.2% and 34.6% with head injury and extremity injury, respectively, and 57% requiring hospitalization. Kappa coefficients of data points of the collection tool ranged from 0.985 to 1, indicating excellent agreement between the two reviewers. Patient demographics The mean age of injured patients in the population was 34.6 (SD 19.9) years. The average injured patient age was younger if male, at 33.1 (SD 18.3) years, compared to females whose average age was 39.1 (SD 23.4) years. Males and individuals aged 15 to 44 years represented the largest number of injuries presenting to the hospital for evaluation (Figure 2a-c). The majority, 59%, of patients were referred from hospitals, clinics, and dis- pensaries in the Kilimanjaro region, for a variety of rea- sons, including primary surgical or orthopedic care, worsening condition or complications occurring during hospitalization at another facility. Sixty-six different health facilities were documented as the transfer facility to this referral hospital, with nearly half, 42.8%, referred from the closest district hospital. The majority of refer- rals arrived via private vehicle or public transportation. Inter-facility transfer to the KCMC Casualty Department is not uncommon. Mechanisms of injury Road traffic injuries (RTI) represent the largest proportion of traumatic events in the patients presenting to the emer- gency department for medical care. Four hundred thirty- two patients, 43.9% (95% CI 40.9, 47.1), reported involve- ment in an RTI as the antecedent mechanism of injury. Categorization of RTI by road traffic user suggests that motorcyclists and pedestrians were the two most common populations impacted by these events. However, over one- third of the records, 38.7%, of the road traffic-related in- jury subjects did not have adequate documentation in the medical record to determine the precise category of RTI. Injuries related to a fall and secondary to an assault were the second and third most common mechanisms reported at 29.5% (95% CI 26.7, 32.4) and 15.0% (95% CI 12.9, 17.3), respectively (Figure 3). Patients aged 15 to 44 years represented the highest proportion of injuries for all mechanisms, except falls and burns. Falls were more common in older patients over 45 years of age, representing 36.7% (95% CI 31.2, 42.6) of