Charles M. Cameron

Ten-year outcomes following traumatic brain injury: A population-based cohort

Primary objective: To quantify the 10 year health service use (HSU) and mortality outcomes for people with a traumatic brain injury (TBI). Research design: A population-based matched cohort study using linked administrative data from Manitoba, Canada (Manitoba Injury Outcome Study). Methods and procedures: An inception cohort (1988–1991) of hospitalized cases with TBI aged 18–64 years (n= 1290) was identified and matched to a non-injured comparison group (n= 1290). Survival analysis, Negative binomial and Poisson regression were used to quantify associations between injury and HSU/mortality outcomes for 10 years following the TBI event. Main outcome and results: The majority of deaths (47.2%) occurred in the first 60 days following injury. Excluding the first 60 days, the adjusted 10 year mortality remained elevated (mortality rate ratio = 1.48, 95% CI = 1.02–2.15). After adjusting for demographic characteristics and pre-existing health status, the TBI cohort had more post-injury hospitalizations (rate ratio (RR) = 1.54, 95% CI = 1.39–1.71), greater cumulative lengths of stay (RR = 5.14, 95% CI = 3.29–8.02) and a greater post-injury physician claims rate (RR = 1.44, 95% CI = 1.35–1.53) than the non-injured cohort. Conclusions: People who sustain a TBI and survive the initial acute phase of care experience substantially increased long-term morbidity compared to the general population, regardless of the level of injury severity.

Ten-year health service use outcomes in a population-based cohort of 21 000 injured adults: the Manitoba Injury Outcome Study

OBJECTIVE To quantify long-term health service use (HSU) following non-fatal injury in adults. METHODS A retrospective, population-based, matched cohort study identified an inception cohort (1988-91) of injured people who had been hospitalized (ICD-9-CM 800-995) aged 18-64 years (n = 21 032) and a matched non-injured comparison group (n = 21 032) from linked administrative data from Manitoba, Canada. HSU data (on hospitalizations, cumulative length of stay, physician claims and placements in extended care services) were obtained for the 12 months before and 10 years after the injury. Negative binomial and Poisson regressions were used to quantify associations between injury and long-term HSU. FINDINGS Statistically significant differences in the rates of HSU existed between the injured and non-injured cohorts for the pre-injury year and every year of the follow-up period. After controlling for pre-injury HSU, the attributable risk percentage indicated that 38.7% of all post-injury hospitalizations (n = 25 183), 68.9% of all years spent in hospital (n = 1031), 21.9% of physician claims (n = 269 318) and 77.1% of the care home placements (n = 189) in the injured cohort could be attributed to being injured. CONCLUSION Many people who survive the initial period following injury, face long periods of inpatient care (and frequent readmissions), high levels of contact with physicians and an increased risk of premature placement in institutional care. Population estimates of the burden of injury could be refined by including long-term non-fatal health consequences and controlling for the effect of pre-injury comorbidity.

Long term health outcomes after injury in working age adults: a systematic review

Background: Estimating the contribution of non-fatal injury outcomes remains a considerable challenge and is one of the most difficult components of burden of disease analysis. The aim of this systematic review was to quantify the effect of being injured compared with not being injured on morbidity and health service use (HSU) in working age adults. Methods: Studies were selected that were population based, had long term health outcomes measured, included a non-injured comparison group, and related to working age adults. Meta-analysis was not attempted because of the heterogeneity between studies. Results: Nine studies met the inclusion criteria. In general, studies found an overall positive association between injury and increased HSU, exceeding that of the general population, which in some studies persisted for up to 50 years after injury. Disease outcome studies after injury were less consistent, with null findings reported. Conclusion: Because of the limited injury types studied and heterogeneity between study outcome measures and follow up, there is insufficient published evidence on which to calculate population estimates of long term morbidity, where injury is a component cause. However, the review does suggest injured people have an increased risk of long term HSU that is not accounted for in current methods of quantifying injury burden.

Long-term mortality following injury in working-age adults: a systematic review

Priorities for prevention activities and planning for services depend on comprehensive knowledge of the distribution of the injury-related burden in the community. The aim of this systematic review was to quantify the effect of being injured, compared with not being injured, on long-term mortality in working age adults. Cohort studies were selected that were population-based, measured mortality post-discharge from inpatient treatment, included a non-injured comparison group and related to working-age adults. Data synthesis was in tabular and text form with a meta-analysis not being possible because of the heterogeneity between studies. Eleven studies met the inclusion criteria. All studies found an overall positive association between injury and increased mortality. While the greatest excess mortality was evident during the initial period post-injury, increased mortality was shown in some studies to persist for up to 40 years after injury. Due to the limited number of injury types studied and heterogeneity between studies, there is insufficient published evidence on which to calculate population estimates of long-term mortality, where injury is a component cause. The review does suggest there is considerable excess mortality following injury that is not accounted for in current methods of quantifying injury burden, and is not used to assess quality and effectiveness of trauma care.

Indicators of injury burden: Which types are the most important?

Injury indicators are used for monitoring the impact of injury prevention initiatives on the population burden of injury. The object of the present study was to identify the types of injury responsible for the major component of the population health burden of injury in a large cohort in Manitoba, Canada. Injury cases (ICD-9-CM 800-995) aged 18 – 64 years were identified from all Manitoba hospital data between 1988 and 1991. Morbidity data were obtained from hospital discharge abstracts 12 months prior to date of injury and for 12 months post-injury. Outcomes for individuals were calculated as the difference pre- and post-injury in hospital inpatient days. Death outcomes in the 12 months post-injury were obtained by linking the cohort with the population registry. Summed outcomes across the population were stratified into injury types based on the International Code of Diseases (ICD) code of the index injury. Outcomes were also stratified by injury severity score categories where the injury severity score was obtained using ICDMAP-90©. When ranked by contribution to the cohorts cumulative hospital inpatient days in the 12 months post-injury, the six most common ICD subchapter groups accounted for 65% of the total inpatient days. These six injury types also accounted for 62% of the total number of deaths in this cohort in 12 months after injury. The suggested injury types to use as indicators of burden include fracture of the lower limb, fracture of the head and neck, poisonings, intracranial injury, fracture of the upper limb, and fracture of skull.