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.

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.

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.

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.

Trajectory of functional outcome and health status after moderate-to-major trauma in Hong Kong: A prospective 5 year cohort study

BACKGROUND

Trauma care systems in Asia have been developing in recent years, but there has been little long-term outcome data from injured survivors. This study aims to evaluate the trajectory of functional outcome and health status up to five years after moderate to major trauma in Hong Kong.

METHODS

We report the five year follow up results of a multicentre, prospective cohort from the trauma registries of three regional trauma centres in Hong Kong. The original cohort recruited 400 adult trauma patients with ISS ≥ 9. Telephone follow up was conducted longitudinally at seven time points, and the extended Glasgow Outcome Scale (GOSE) and Short-Form 36 (SF36) were tracked.

RESULTS

119 out of 309 surviving patients (39%) completed follow up after 5 years. The trajectory of GOSE, PCS and MCS showed gradual improvements over the seven time points. 56/119 (47.1%) patients reported a GOSE = 8 (upper good recovery), and the mean PCS and MCS was 47.8 (95% CI 45.8, 49.9) and 55.8 (95% CI 54.1, 57.5) respectively at five years. Univariate logistic regression showed change in PCS - baseline to 1 year and 1 year to 2 years, and change in MCS - baseline to 1 year were associated with GOSE = 8 at 5 years. Linear mixed effects model showed differences in PCS and MCS were greatest between 1-month and 6-month follow up.

CONCLUSIONS

After injury, the most rapid improvement in PCS and MCS occurred in the first six to 12 months, but further recovery was still evident for MCS in patients aged under 65 years for up to five years.

Differences in Injury Pattern and Mortality between Hong Kong Elderly and Younger Patients

Background

The rapidly aging population in Hong Kong is causing an impact on our health care system. In Hong Kong, 16.5% of emergency department trauma patients are aged ≥65 years.

Objective

We aim to compare factors associated with trauma and differences in trauma mortality between elderly (≥65 years) and younger adult patients (15 to 64 years) in Hong Kong.

Methods

A retrospective observational study was performed using trauma registry data from the Prince of Wales Hospital, a 1200–bed acute hospital which is a regional trauma centre.

Results

A total of 2172 patients (331 [15.2%] elderly and 1841 [84.8%] younger) were included. Male patients predominated in the younger adult group but not in the elderly group. Compared with younger patients, elderly patients had more low falls and pedestrian-vehicle crashes and sustained injuries to the head, neck and extremities more frequently. The odds ratio (OR) for death following trauma was 5.5 in the elderly group (95% confidence interval [CI] 3.4–8.9, p>0.0001). Mortality rates increased progressively with age (p>0.0001) and were higher in the elderly at all levels of Injury Severity Score (ISS). Age ≥65 years independently predicted mortality (OR=5.7, 95% CI 3.5–9.3, p>0.0001). The elderly had a higher co-morbidity rate (58.6% vs. 14.1%; p>0.01). There was a lower proportion of trauma call activations for the elderly group (38.6% vs. 53.3%; p>0.01).

Conclusion

Elderly trauma patients differ from younger adult trauma patients in injury patterns, modes of presentation of significant injuries and mortality rates. In particular, the high mortality of elderly trauma requires renewed prevention efforts and aggressive trauma care to maximise the chance of survival.

Assessment of quality of life and functional outcome in patients sustaining moderate and major trauma: a multicentre, prospective cohort study

BACKGROUND

Trauma care systems aim to reduce both death and disability, yet there is little data on post-trauma health status and functional outcome.

OBJECTIVES

To evaluate baseline, discharge, six month and 12 month post-trauma quality of life, functional outcome and predictors of quality of life in Hong Kong.

METHODS

Multicentre, prospective cohort study using data from the trauma registries of three regional trauma centres in Hong Kong. Trauma patients with an ISS≥9 and aged≥18 years were included. The main outcome measures were the physical component summary (PCS) score and mental component summary (MCS) scores of the Short-Form 36 (SF36) for health status, and the extended Glasgow Outcome Scale (GOSE) for functional outcome.

RESULTS

Between 1 January 2010 and 31 September 2010, 400 patients (mean age 53.3 years; range 18-106; 69.5% male) were recruited to the study. There were no statistically significant differences in baseline characteristics between responders (N=177) and surviving non-responders (N=163). However, there were significant differences between these groups and the group of patients who died (N=60). Only 16/400 (4%) cases reported a GOSE≥7. 62/400 (15.5%) responders reached the HK population norm for PCS. 125/400 (31%) responders reached the HK population norm for MCS. If non-responders had similar outcomes to responders, then the percentages for GOSE≥7 would rise from 4% to 8%, for PCS from 15.5% to 30%, and for MCS from 31% to 60%. Univariate analysis showed that 12-month poor quality of life was significantly associated with age>65 years (OR 4.77), male gender (OR 0.44), pre-injury health problems (OR 2.30), admission to ICU (OR 2.15), ISS score 26-40 (OR 3.72), baseline PCS (OR 0.89), one-month PCS (OR 0.89), one-month MCS (OR 0.97), 6-month PCS (OR 0.76) and 6-month MCS (OR 0.97).

CONCLUSION

For patients sustaining moderate or major trauma in Hong Kong at 12 months after injury<1 in 10 patients had an excellent recovery, ≤3 in 10 reached a physical health status score≥Hong Kong norm, although as many as 6 in 10 patients had a mental health status score which is≥Hong Kong norm.

Simulation of survivorship bias in observational studies on plasma to red blood cell ratios in massive transfusion for trauma

BACKGROUND

Observational studies on injured patients requiring massive transfusion have found a survival advantage associated with use of equivalent number of units of fresh frozen plasma (FFP) and packed red blood cells (RBCs) compared with use of FFP based on conventional guidelines. However, a survivorship bias might have favoured the higher use of FFP because patients who died early never had the chance to receive sufficient FFP to match the number of RBC units transfused.

METHODS

A Markov model using trauma data from local hospitals was constructed and various FFP transfusion scenarios were applied in Monte Carlo simulations in which the relative risk of death associated with exposure to high FFP transfusion was set at 1.00, so that the FFP : RBC ratio had no influence on mortality outcome.

RESULTS

Simulation results showed that the relative risk associated with exposure to high FFP transfusion was less than 1.00 (0.33-0.56 based on programmed delays in achieving an FFP : RBC ratio of 1 : 1-2), thus demonstrating a survivorship bias in favour of FFP : RBC equal to or more than 1 : 1-2 in certain observational trauma studies. This bias was directly proportional to the delay in achieving a FFP : RBC ratio of 1 : 1-2 during resuscitation.

CONCLUSION

Some observational studies comparing low and high FFP administration in injured patients requiring massive transfusion probably involve survivorship bias that inflates or creates a survival advantage in favour of a higher FFP : RBC ratio.

Functional outcome after head injury: comparison of 12-45 year old male and female hormonally active patients

OBJECTIVES

Head injury is the leading cause of death in patients with major trauma, but little is known of post-trauma rehabilitation morbidity in Hong Kong. The purpose of this study was to identify factors affecting functional outcome in hormonally active patients 6 months after head injury.

METHODS

Secondary analysis of the trauma registry database with data collected prospectively at two trauma centres between January 2001 and December 2007. Demographic and trauma data for patients aged 12-45 years with a head Abbreviated Injury Score ≥3 were analysed. The Glasgow outcome scale (GOS) was used for assessment and was assessed 6 months after head injury. The primary outcome measure was a composite poor outcome, namely "dead, vegetative and severely disabled" measured using the GOS.

RESULTS

Of 698 patients included in the study (mean age 29 years; range 12-45 years; 75.8% male), 581 (83.2%) had a good outcome, and 117 (16.8%) met the primary outcome measure, namely a poor outcome, including 88 (12.6%) patients who died. 453 (64.9%) patients had an injury severity score (ISS) of 16-40, and 102 (14.6%) patients had an ISS>40. 220 (31.5%) patients underwent head injury related operation. The mean length of stay in the intensive care unit (ICU) was 3.9 days. Univariate analysis showed that high ISS, Emergency Department (ED) systolic blood pressure (SBP)>160mmHg or <90mmHg, respiratory rate<12/min or >24/min, low ED Glasgow Coma Score (GCS), trauma call activation, head related operation and ICU admission were related to poor outcome. Multivariate analysis showed that high ISS, low or high ED SBP and low ED GCS were related to poor functional outcome.

CONCLUSION

This study showed that ISS, ED SBP and ED GCS were related to poor functional outcome. Gender showed no statistically significant relationship with functional outcome.

Traumatic intracerebral haemorrhage: is the CT pattern related to outcome?

It is believed by many neurosurgeons that in addition to age and neurological status, the CT patterns of traumatic intracerebral haemorrhages are related to outcome. The aim of this study was to find out whether this is the case. The study was conducted in a regional level I trauma centre in Hong Kong. We prospectively collected data of patients with traumatic intracerebral haematomas over a 4-year period. Of 464 patients with head injuries, traumatic intracerebral haematoma was significantly associated with inpatient mortality and one year unfavorable outcome after adjustment for age, sex, post-resuscitation GCS, and presence of acute subdural haematoma. One hundred-and-fourteen patients had traumatic intracerebral haematomas and were included for further analysis. The mean age was 49, the male to female ratio was 2 to 1, and the median Glasgow Coma Scale (GCS) score on admission was 12. Logistic regression analysis showed that age and GCS score/GCS motor component score were significant factors for inpatient mortality, one-year mortality and one-year outcome. There was an association between temporal haematomas and inpatient mortality, subdural haematomas and inpatient mortality, and bilateral haematomas and unfavourable one-year outcome. In patients with severe head injury, a traumatic haematoma of more than 50 ml was associated higher inpatient mortality. In addition to age and GCS score, the CT patterns of bilateral haematomas, temporal haematomas and associated subdural haematomas were suggestive of poor outcome or mortality.

Bicycle related injuries presenting to a trauma centre in Hong Kong

BACKGROUND

Bicycle riding is a popular leisure activity and an important means of transportation in Hong Kong. Young cyclists' riding behaviour causes injury patterns which may differ from older riders. The aim of this study is firstly to describe bicycle related injuries presenting to a regional trauma centre in Hong Kong, and secondly to compare patients aged > 15 years with those patients aged < or = 15 years.

METHODS

This retrospective observational study examined all bicycle related injury patients presenting to the ED of the Prince of Wales Hospital (PWH) in 2006.

RESULTS

Results showed that bicycle helmet use was low in Hong Kong suggesting that the wearing of helmets when cycling should be promoted. Bicycle related injuries were common in children but the injuries in adults were more serious. Head and limb injuries were common and limbs on the left side were 2.5 times more likely to be injured than those on the right. The older group were more likely to be involved in a motor vehicle collision and sustained more severe injuries than the younger group. They had more serious head and neck, face, thorax and abdominal injuries compared to the younger group.

CONCLUSION

Prevention strategies should include more widespread helmet use and increasing bicycle lane provision to enable traffic separation in Hong Kong. The three 'E' approaches (education, enforcement and environment) should be implemented to prevent bicycle injuries in Hong Kong.