Impact of AIS 2015 versus 1998 on injury severity scoring and mortality prediction - single centre retrospective comparison study.

BACKGROUND: A key component of trauma system evaluation is the Injury Severity Score (ISS). The ISS is dependent on the AIS, and as AIS versions are updated this effects the number of patients within a health system which are considered severely injured (ISS >15). This study aims to analyse the changes comparing AIS1998 and AIS2015, and its impact on injury severity scoring and survival prediction model in a major trauma centre. METHODS: This retrospective study reviewed all blunt trauma admissions from 1 January 2020 to 31 December 2020 from the trauma registry of Prince of Wales Hospital, Hong Kong. Patients were manually double coded with AIS1998 and AIS2015 by the same experienced trauma nurse who have completed both AIS 1998 and AIS 2015 Courses. AIS patterns and Injury Severity Scores (ISS) derived from AIS 1998 and 2015 were compared using the Wilcoxon Signed Rank Test. The area under the receiving operator curve (AUROC) was compared based on the Trauma and Injury Severity Score (TRISS) model using AIS 1998 and AIS 2015. RESULTS: 739 patients were included. There were 34 deaths within 30 days (30-day mortality rate 4.6%). Patients coded with AIS2015 compared with AIS1998 had significant reductions in the classification of serious, severe and critical categories of AIS, with a substantial increase in the mild and moderate categories. The largest reduction was observed in the head and neck region (Z = -11.018, p < 0.001), followed by the chest (Z = -6.110, p < 0.001), abdomen (Z = -4.221, p < 0.001) and extremity regions (Z = -4.252, p < 0.001). There was a 27% reduction in number of cases with ISS >15 in AIS2015 compared with AIS1998. Rates of 30-day mortality, ICU admission, emergency operation and trauma team activation of ISS > 15 using AIS 1998 were similar to the cut off for New Injury Severity Score (NISS) >12 using AIS 2015. The AUROC from the TRISS (AIS2015) was 0.942, and not different from the AUROC for TRISS (AIS1998) of 0.936. The sensitivity and specificity were 93.9% and 82.1% for TRISS (AIS2015), and 93.9% and 76.0% for TRISS (AIS1998). CONCLUSION: Trauma centres should be aware of the impact of the AIS2015 update on the benchmarking of trauma care, and consider the need for updating the ISS cut off for major trauma definitions.

The impact of SARS and COVID-19 on major trauma in Hong Kong.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has been enormously disruptive and harmful to people around the world, but its impact on other illnesses and injuries has been more variable. To evaluate the ramification of infectious disease outbreaks on major traumatic injuries, we compared changes in the incidence of major trauma cases during the 2003 Severe Acute Respiratory Syndrome (SARS) period with COVID-19 in 2020. METHODS: Data were analyzed from the trauma registry of a major, tertiary-care teaching hospital in Hong Kong. Patients presenting with major traumatic injuries during the first six months of 2001-03 and 2018-20 were retrieved for analysis. Patient characteristics, injury mechanism, admitting service, and emergency department (ED)/hospital lengths of stay (LOS) were recorded. Raw and adjusted survival rates (using the modified Trauma Injury Severity Score (TRISS)) were recorded. RESULTS: The number of trauma cases fell dramatically during 2003 and 2020 compared with previous years. In both 2003 and 2020, the number of trauma registry patients fell by 49% in April (compared to the preceding reference years of 2001/02 and 2018/19, respectively). Patient characteristics, treatments, and outcomes were also different during the outbreak years. Comparing 2003 to 2020 relative to their respective reference baselines, the percentages of injuries that happened at home, patients without co-morbidities, and patients' mean age all increased in 2003 but decreased in 2020. Work-place injuries drastically dropped in 2003, but not in 2020. Average ED LOS dropped in 2003 by 36.4 min (95% CI 12.5, 60.3) but declined by only 14.5 min (95% CI -2.9, 32.1) in 2020. Both observed and expected 30-day mortality declined in 2020 vs. 2003 (observed 4.5% vs. 11.7%, p = 0.001, OR 0.352, 95% CI 0.187, 0.661) (expected 4.5% vs 11.6%, p = 0.002, OR 0.358, 95% CI 0.188, 0.684). CONCLUSION: Major trauma cases dropped by half during both the peak of the 2003 SARS and 2020 COVID-19 pandemics in Hong Kong, suggesting a trend for future pandemic planning. If similar findings are seen at other trauma centers, proactive personnel and resource allocations away from trauma towards medical emergency systems may be more appropriate for future pandemics.

Seven-year excess mortality, functional outcome and health status after trauma in Hong Kong.

PURPOSE: The purpose was to investigate long-term health impacts of trauma and the aim was to describe the functional outcome and health status up to 7 years after trauma. METHODS: We conducted a prospective, multi-centre cohort study of adult trauma patients admitted to three regional trauma centres with moderate or major trauma (ISS ≥ 9) in Hong Kong (HK). Patients were followed up at regular time points (1, 6 months and 1, 2, 3, 4, 5, 6, and 7 years) by telephone using extended Glasgow Outcome Scale (GOSE) and the Short-Form 36 (SF36). Observed annual mortality rate was compared with the expected mortality rate estimated using the HK population cohort. Linear mixed model (LMM) analyses examined the changes in SF36 with subgroups of age ≥ 65 years, ISS > 15, and GOSE ≥ 5 over time. RESULTS: At 7 years, 115 patients had died and 48% (138/285) of the survivors responded. The annual mortality rate (AMR) of the trauma cohort was consistently higher than the expected mortality rate from the general population. Forty-one percent of respondents had upper good recovery (GOSE = 8) at 7 years. Seven-year mean PCS and MCS were 45.06 and 52.06, respectively. LMM showed PCS improved over time in patients aged < 65 years and with baseline GOSE ≥ 5, and the MCS improved over time with baseline GOSE ≥ 5. Higher mortality rate, limited functional recovery and worse physical health status persisted up to 7 years post-injury. CONCLUSION: Long-term mortality and morbidity should be monitored for Asian trauma centre patients to understand the impact of trauma beyond hospital discharge.

RISC II is superior to TRISS in predicting 30-day mortality in blunt major trauma patients in Hong Kong.

PURPOSE: Hong Kong (HK) trauma registries have been using the Trauma and Injury Severity Score (TRISS) for audit and benchmarking since their introduction in 2000. We compare the mortality prediction model using TRISS and Revised Injury Severity Classification, version II (RISC II) for trauma centre patients in HK. METHODS: This was a retrospective cohort study with all five trauma centres in HK. Adult trauma patients with Injury Severity Score (ISS) > 15 suffering from blunt injuries from January 2013 to December 2015 were included. TRISS models using the US and local coefficients were compared with the RISC II model. The primary outcome was 30-day mortality and the area under the receiver operating characteristic curve (AUC) for tested models. RESULTS: 1840 patients were included, of whom 1236/1840 (67%) were male. Median age was 59 years and median ISS was 25. Low falls were the most common mechanism of injury. The 30-day mortality was 23%. RISC II yielded a superior AUC of 0.896, compared with the TRISS models (MTOS: 0.848; PATOS: 0.839; HK: 0.858). Prespecified subgroup analyses showed that all the models performed worse for age ≥ 70, ASA ≥ III, and low falls. RISC II had a higher AUC compared with the TRISS models in all subgroups, although not statistically significant. CONCLUSION: RISC II was superior to TRISS in predicting the 30-day mortality for Hong Kong adult blunt major trauma patients. RISC II may be useful when performing future audit or benchmarking exercises for trauma in Hong Kong.

Univariate and Multivariable Analyses on Independent Predictors for Cervical Spinal Injury in Patients with Head Injury.

OBJECTIVE: This study aims to identify independent factors associated with cervical spinal injuries in head-injured patients. The extent of injuries to other body parts was assessed by the Abbreviated Injury Scale (AIS) and was included in the analysis. METHODS: Consecutive head-injured patients admitted via the emergency department from January 1, 2014 to December 31, 2016 were retrospectively reviewed. The inclusion criteria were head-injured patients with an Abbreviated Injury Scale (AIS) score ≥2 (i.e., head injuries with intracranial hematoma or skull fracture). Patients with minor head injuries with only scalp abrasions or superficial lacerations without significant intracranial injuries (i.e., head injury AIS score = 1) were excluded. The primary outcome was to identify independent predictors associated with cervical spinal injuries in these head-injured patients. Univariate and multivariable analyses were conducted. RESULTS: A total of 1105 patients were identified. Of these patients, 11.2% (n = 124) had cervical spinal injuries. Univariate and multivariable analyses identified male gender (P = 0.006), the presence of thoracic injury (including rib fracture, hemothorax, or pneumothorax) (P = 0.010), and hypotension with systolic blood pressure <90 mm Hg on admission (P = 0.009) as independent predictors for cervical spinal injury in head-injured patients. CONCLUSIONS: This study showed that about 1 in 10 patients with significant head injury had cervical spine injury, usually associated with fracture or dislocation. Male gender, the presence of thoracic injury, and hypotension on admission were independent risk factors associated with cervical spinal injuries.

Return to work after injury in Hong Kong: prospective multi-center cohort study.

PURPOSE: Trauma remains a major cause of morbidity and disability worldwide; however, reliable data on the health status of an urban Asian population after injury are scarce. The aim was to evaluate 1-year post-trauma return to work (RTW) status in Hong Kong. METHODS: This was a prospective, multi-center cohort study involving four regional trauma centers from 2017 to 2019 in Hong Kong. Participants included adult patients entered into the trauma registry who were working or seeking employment at the time of injury. The primary outcome was the RTW status up to 1 year. The Extended Glasgow Outcome Scale, 12-item Short Form (SF-12) survey and EQ5D were also obtained during 1-, 3-, 6-, 9-, and 12-month follow-ups. Multivariable Cox proportional hazards regression analysis was used for analysis. RESULTS: Six hundred and seven of the 1115 (54%) recruited patients had RTW during the first year after injury. Lower physical requirements (p = 0.003, HR 1.51) in pre-injury job nature, higher educational levels (p < 0.001, HR 1.95), non-work-related injuries (p < 0.001, HR 1.85), shorter hospital length of stay (p = 0.007, HR 0.98), no requirement for surgery (p = 0.006, HR 1.34), and patients who could be discharged home (p = 0.006, HR 1.43) were associated with RTW within 12 months post-injury. In addition, 1-month outcomes including extended Glasgow Outcome Scale ≥ 6 (p = 0.001, HR 7.34), higher mean SF-12 physical component summary (p = 0.002, HR 1.02) and mental component summary (p < 0.001, HR 1.03), and higher EQ5D health index (p = 0.018, HR 2.14) were strongly associated with RTW. CONCLUSIONS: We have identified factors associated with failure to RTW during the first year following in Hong Kong including socioeconomic factors, injury factors and treatment-related factors and 1-month outcomes. Future studies should focus on the interventions that can impact on RTW outcomes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03219424.

Major trauma care in Hong Kong and Germany: a trauma registry data benchmark study.

BACKGROUND: Trauma remains a leading cause of death and effective trauma management within a well-developed trauma system has been shown to reduce morbidity and mortality. A trauma registry, as an integral part of a mature trauma system, can be used to monitor the quality of trauma care and to provide a means to compare local versus international standards. Hong Kong and Germany both have highly developed health care services. We compared the performance of trauma systems including outcomes among major trauma victims (ISS > 15) over a 3-year period (2013-2015) in both settings using trauma registry data. METHODS: This study was a retrospective analysis of prospectively collected data from trauma registries in Hong Kong and Germany. Data from 01/2013 to 12/2015 were extracted from the trauma registries of the five trauma centers in Hong Kong and the TraumaRegister DGU® (TR-DGU). The study cohort included adults (≥ 18 years) with major trauma (ISS > 15). Data related to patient characteristics, nature of the injury, prognostic parameters to calculate the RISC II score, outcomes and clinical management were collected and compared. RESULTS: Datasets from 1,864 Hong Kong and 10,952 German trauma victims were retrieved from respective trauma registries. The unadjusted mortality in Hong Kong (22.4%) was higher compared to Germany (19.2%); the difference between observed and expected mortality was higher in Hong Kong (+ 2.7%) than in Germany (- 0.5%). The standardized mortality ratio (SMR) in Hong Kong and Germany were 1.138 (95% CI 1.033-1.252) and 0.974 (95% CI 0.933-1.016), respectively, and the adjusted death rate in Hong Kong was significantly higher compared to the calculated RISC II data. However, patients in Hong Kong were significantly older, had more pre-trauma co-morbidities, more head injuries, shorter hospital and ICU stays and lower ICU admission rates. CONCLUSION: Hong Kong had a higher mortality rate and a statistically significantly higher standardized mortality ratio (SMR) after RISC II adjustment. However, multiple differences existed between trauma systems and patient characteristics.