Incidence of major depression diagnoses in the Canadian Armed Forces: longitudinal analysis of clinical and health administrative data.

PURPOSE: Major depression is a leading cause of morbidity in military populations. However, due to a lack of longitudinal data, little is known about the rate at which military personnel experience the onset of new episodes of major depression. We used a new source of clinical and administrative data to estimate the incidence of major depression diagnoses in Canadian Armed Forces (CAF) personnel, and to compare incidence rates between demographic and occupational factors. METHODS: We extracted all data recorded in the electronic medical records of CAF Regular Force personnel, at every primary care and mental health clinical encounter since 2016. Using a 12-month lookback period, we linked data over time, and identified all patients with incident diagnoses of major depression. We then linked clinical data to CAF administrative records, and estimated incidence rates. We used multivariate Poisson regression to compare adjusted incidence rates between demographic and occupational factors. RESULTS: From January to December 2017, CAF Regular Force personnel were diagnosed with major depression at a rate of 29.2 new cases per 1000 person-years at risk. Female sex, age 30 years and older, and non-officer ranks were associated with significantly higher incidence rates. CONCLUSIONS: We completed the largest study to date on diagnoses of major depression in the Canadian military, and have provided the first estimates of incidence rates in CAF personnel. Our results can inform future mental health resource allocation, and ongoing major depression prevention efforts within the Canadian Armed Forces and other military organizations.

Management of adult splenic injuries in Ontario: a population-based study.

OBJECTIVES: To determine the population-based incidence of splenic injuries in the Province of Ontario, the proportion of splenic injuries treated by observation, splenectomy and splenorrhaphy, changes in management over time and the variation in management of splenic injuries among Ontario hospitals. DESIGN: A retrospective cohort study. PATIENTS: All adults (older than 16 years) admitted with a diagnosis of splenic injury (clinical modification of the International Classification of Diseases, 9th revision) to acute care hospitals in Ontario between 1991 and 1994, identified from the Ontario Trauma Registry. RESULTS: The incidence of splenic injury was 1.7 cases per 1000 trauma admissions per year. Patients with splenic injury were young (median age 32 years) and male (71%), and the death rate was 8%. Observation was the commonest method of treatment (69%), followed by splenectomy (28%) and splenorrhaphy (4%). The use of observation increased over the study period from 59% to 75% (p < 0.001). There was significant variation in the use of observation among hospitals (range 11% to 100%, p < 0.0001). CONCLUSIONS: The majority of splenic injuries are managed by observation with an acceptable hospital death rate. The use of observation has increased over time, confirming the growing adoption of this management approach by most hospitals in the province when feasible. Splenorrhaphy was infrequently performed despite reports to the contrary from many centres in the United States. There was significant variation in splenic injury management, suggesting the need for further refinement and dissemination of practical guidelines for splenic salvage.

Use of abdominal computed tomography in blunt trauma: do we scan too much?

OBJECTIVES: To determine what proportion of abdominal computed tomography (CT) scans ordered after blunt trauma are positive and the applicability and accuracy of existing clinical prediction rules for obtaining a CT scan of the abdomen in this setting. SETTING: A leading trauma hospital, affiliated with the University of Ottawa. DESIGN: A retrospective cohort study. PATIENTS AND METHODS: All patients with blunt trauma admitted to hospital over a 1-year period having an Injury Severity Score (ISS) greater than 12 who underwent CT of the abdomen during the initial assessment. Recorded data included age, sex, Glasgow Coma Scale (GCS) score, ISS, type of injuries, number of abdominal CT scans ordered, and scan results. Two clinical prediction rules were found in the literature that identify patients likely to have intra-abdominal injuries. These rules were applied retrospectively to the cohort. The predicted proportion of positive CT scans was compared with the observed proportion, and the sensitivity, specificity, and accuracy were estimated. RESULTS: Of the 297 patients entered in the study, 109 underwent abdominal CT. The median age was 32 years, 71% were male and the median ISS was 24. In only 36.7% (40 of 109) of scans were findings suggestive of intra-abdominal injuries. Application of one of the clinical prediction rules gave a sensitivity of 93.8% and specificity of 25.5% but excluded 23% of patients because of a GCS score less than 11. The second prediction rule tested could be applied to all patients and was highly sensitive (92.5%) and specific (100.0%). CONCLUSIONS: The assessment of the abdomen in blunt trauma remains a challenge. Accuracy in predicting positive scans in equivocal cases is poor. Retrospective application of an existing clinical prediction rule was found to be highly accurate in identifying patients with positive CT findings. Prospective use of such a rule could reduce the number of CT scans ordered without missing significant injuries.

An economic evaluation of trauma care in a Canadian lead trauma hospital.

BACKGROUND: The objective was to determine the average cost per quality-adjusted life year (QALY) gained of treating trauma victims at a tertiary trauma hospital and to determine the cost-effectiveness of trauma care at this center. The setting was a tertiary trauma center in the province of Ontario, Canada. The study population consisted of consecutive trauma admissions with ISS > 12 from April, 1994 to April, 1996. The study was of a retrospective cohort design with a cross-sectional survey. METHODS: The hospital perspective was taken. Costs were determined from a retrospective cohort using a hospital-based case-costing system. Utility estimates for calculation of QALYs gained were obtained using a cross-sectional survey design. Cost-effectiveness was determined by estimating the incremental cost/QALY attributable to treatment at the trauma center. Sensitivity analysis was employed to vary assumptions about the proportion of costs and increased survival. RESULTS: 484 patients with a median age of 39 years and a median ISS of 22 were studied. The average cost per QALY was $1,721, with a maximum value of $3,861. The increase in cost per QALY gained for treatment in a tertiary care center as opposed to a nontrauma center was $4,303, assuming a 20% increase in survival and assuming that the existence of the center increased the cost of care by 50%. The incremental cost/QALY ranged from $191 to $15,492 in the sensitivity analysis varying assumptions about the increased proportion of costs and survival attributable to care at the tertiary trauma center. CONCLUSIONS: This is the first economic evaluation of tertiary trauma care which includes both costs as opposed to charges as well as estimates of the QALYs gained. The results suggest that tertiary trauma care is cost-effective and less costly than treatment programs for other disease conditions when the quality-adjusted life years gained are included in the evaluation.

Differential performance of TRISS-like in early and late blunt trauma deaths.

OBJECTIVES: (1) To independently validate the Trauma and Injury Severity Score-Like (TRISS-Like) model derived by Offner et al. (Revision of TRISS for intubated patients. J Trauma. 1992;32:32-35) in a population of Canadian blunt trauma victims, and (2) to compare the ability of this model to predict mortality in early and late trauma deaths. STUDY POPULATION: Prospective cohort of blunt trauma cases with Injury Severity Score > 12 identified from the Ontario Trauma Registry over a 5-year period. STUDY DESIGN: The TRISS-Like model consisting of age, Injury Severity Score, systolic blood pressure, and best motor response of the Glasgow Coma Scale was evaluated as to its ability to predict mortality by determining the sensitivity, specificity, and the area under the receiver operating characteristic curve. The sample was then divided into early (< or = 7 days) and late mortality subgroups in which model performance was evaluated with respect to time of death. RESULTS: A total of 7,703 patients were included in this analysis. The overall mortality was 12.3%. The TRISS-Like model allowed for assessment of an additional 23% of patients than would standard TRISS and performed with a sensitivity of 97.1%, specificity of 39.8% and an area under the receiver operating characteristic curve of 0.873. Analysis of mortality with respect to time demonstrated that 75% of deaths occurred by day 7. The specificity and receiver operating characteristic area increased in the early (< or = 7 days) subgroup, 46.5% and 0.935, respectively, compared with 20.8% and 0.778 in the late mortality group. CONCLUSIONS: TRISS-Like demonstrated similar performance to that reported with the standard TRISS model but with the additional advantage that it is more generalizable because it can be applied to intubated patients. TRISS-Like demonstrated substantially superior performance in early trauma deaths compared with those that occurred late. This differential performance may be because the model does not include risk factors for late mortality.

Management of splenic injuries in a Canadian trauma centre.

OBJECTIVES: To document the current practice pattern for the treatment of splenic injuries in one Canadian trauma centre and to identify factors that determined which method was employed. DESIGN: A cohort study. SETTING: A Canadian lead trauma centre. PATIENTS: A cohort of 100 patients with splenic injury treated at one trauma hospital over 5 years was identified from a prospective trauma database. MAIN OUTCOME MEASURES: The success rate and failure rate for splenic salvage by splenectomy, splenorrhaphy or observation. Volume of blood transfused, injury severity score (ISS) and method of diagnosis. RESULTS: The median ISS for the cohort was 34 (36 for splenectomy, 38 for splenorrhaphy and 35 for observation). A blunt mechanism of injury was present in 96%. The diagnosis was made by computed tomography (CT) in 55%. Splenic salvage was accomplished in 51 patients; of these, 44 (86%) were in the observation group, and the success rate was 90% (within the range reported in the literature). Only seven patients underwent splenorrhaphy. CT was performed more frequently in the observation group than in the splenectomy group (82% v. 25%, p < 0.0001). The splenectomy group had more blood transfused than the successful observation group (mean units 15 v. 3, p = 0.0001) and had a higher median ISS (36 v. 29, p = 0.02). Multivariate analysis revealed that the method of diagnosis (CT v. diagnostic peritoneal lavage) was the strongest factor associated with how the splenic injury was treated. CONCLUSIONS: The finding in this report of an increase in observational treatment of splenic injuries represents a shift in practice from a previous Canadian report and is in keeping with recent published trends from the United States. Future studies are needed to assess whether any strong regional practice pattern variations in the management of blunt splenic injuries exists in other trauma centres across Canada.

Validation of trauma and injury severity score in blunt trauma patients by using a Canadian trauma registry.

OBJECTIVE: To compare outcomes in blunt trauma by using Trauma and Injury Severity Score (TRISS) models derived from the Major Trauma Outcome Study (MTOS) and the Ontario Trauma Registry (OTR) as well as to evaluate the role of the Revised Trauma Score within the TRISS model. METHODS: Consecutive blunt trauma cases from 11 Level I trauma centers over a 4-year period were identified from the OTR. Coefficients of the Revised Trauma Score were modified using the Ontario data and this score was tested by using the Hosmer-Lemeshow Goodness of Fit Test. Two Ontario-specific TRISS models were developed with revised coefficients. The first used the standard Revised Trauma Score and the second used the Revised Trauma Score with regenerated coefficients. The accuracy of mortality predictions for all models were compared by using a Hosmer-Lemeshow Goodness of Fit procedure. Additionally, each TRISS models performance characteristics and receiver operating characteristic (ROC) curves were used to evaluate their discriminative capabilities. RESULTS: A total of 5,436 cases were incorporated in the analysis. Patients with all component TRISS variables had a significantly lower mortality compared to all blunt trauma patients (7.0% vs. 15.5%,p < 0.01). Use of the Revised Trauma Score led to the exclusion of 40% of cases because of absent data necessary to compute the score. The Hosmer-Lemeshow Goodness of Fit statistic for the Revised Trauma Score was 79.45 (p = 0.0001). The Hosmer-Lemeshow Goodness of Fit Statistic ranged from 11.42, p = 0.175 and 13.1, p = 0.125 for the Ontario TRISS models compared to 25.62, p < 0.005 for the MTOS TRISS model. Sensitivity of all three TRISS models ranged from 98% to 99% with specificity ranging from 24% to 35%. ROC curves were identical for all three TRISS models. CONCLUSIONS: TRISS demonstrated satisfactory performance in a Canadian blunt trauma population. Although revision of coefficients led to a better fit on the Hosmer-Lemeshow statistic, ROC curves demonstrated virtually identical performance of the MTOS and Ontario-based TRISS models. The poor performance of the Revised Trauma Score and the observation that its use led to the exclusion of 40% of cases with a higher mortality raises concerns regarding its use in the TRISS model.

Adult respiratory distress syndrome: a systemic overview of incidence and risk factors.

OBJECTIVE: To determine the published incidence of adult respiratory distress syndrome (ARDS) as well as the clinical evidence supporting a casual association between ARDS and its major risk factors. DATA SOURCES: The National Library of Medicine MEDLINE database and the bibliographies of selected articles. STUDY SELECTION: Clinical studies were selected from the English literature, if they pertained to either the incidence of ARDS or its association with one or more commonly identified risk factors. DATA EXTRACTION: All relevant studies identified by the search were evaluated for strength of design, and risk factors were scored according to established criteria for the strength of causation. DATA SYNTHESIS: A total of 83 articles were considered relevant: six of incidence and 77 on risk factors. Only 49% of the 83 articles provided a definition of ARDS; a definition of risk factors was given in 64%, and 23% had no definition for either ARDS or risk factors. The published, population-based incidence of ARDS ranges from 1.5 to 5.3/10(5) population/yr. The strongest clinical evidence supporting a cause-effect relationship was identified for sepsis, aspiration, trauma, and multiple transfusions. The weakest clinical evidence was identified for disseminated intravascular coagulation. The following study types were represented by the 77 articles on risk factors: observational case-series (56%); cohorts (23%); case-controls (12%); nonrandomized clinical trials (5%); and randomized clinical trials (3%). Only a single study reported an odds ratio. CONCLUSIONS: The significant variation in the incidence of ARDS is attributed to differences in the type and strength of study designs, as well as definitions or ARDS. While a substantial body of evidence exists concerning a casual role of ARDS risk factors, such as sepsis, aspiration, and trauma, > 60% of clinical studies employed weak designs. The lack of reproducible definitions for ARDS or its potential risk factors in 49% of studies raises concerns about the validity of the conclusions of these studies regarding the association between ARDS and the supposed risk factors.