A population-based study on the epidemiology of firearm-related injury in Nova Scotia.

OBJECTIVE: Firearm-related trauma is a significant cause of preventable mortality. In 2020, Nova Scotia experienced the largest mass shooting in Canadian history. The objective of this study was to describe the epidemiology of firearm-related injury and death in Nova Scotia and to assess for factors associated with mortality. METHODS: A retrospective observational study of all major trauma patients in Nova Scotia who sustained firearm-related injuries between 2001 and 2020 was conducted. Data was collected from the Nova Scotia Trauma Registry and the Nova Scotia Medical Examiner Service. Injury rates were evaluated over time, by age/sex, and by intent (assault/homicide, self-harm, other), and were mapped by municipality. Characteristics of survivors and non-survivors were compared using t-tests and chi-square analysis. A multivariate logistic regression model was created to assess for predictors of mortality. RESULTS: A total of 776 firearm-related injuries occurred over the 19-year study period, for an overall age- and sex-adjusted firearm injury rate of 4.44 per 100,000 population. Patients ranged in age from 6 to 92 years (mean 45.0±19.2 years) and most were male (95.6%; 742/776). Injuries were predominantly self-inflicted (65%; 504/776). The majority of patients died from their injuries (72%; 558/776); 64% (497/776) died at the scene. The overall age- and sex-adjusted firearm mortality rate was 3.18 per 100,000. Most non-survivors had injuries that were self-inflicted (83.2%; 464/558). Increasing age (OR 1.02, 95% CI 1.00-1.04) and increasing Injury Severity Score (OR 1.11, 95% CI 1.07-1.15) were associated with greater likelihood of mortality. Activation of the trauma team was associated with survival (OR 0.04, 95% CI 0.02-0.10). CONCLUSION: Trauma patients with firearm-related injuries were predominantly male and most injuries were self-inflicted among middle-aged to older patients. Younger patients tended to be victims of homicide/assault and were more likely to survive their injuries.

The effect of legislation on firearm-related deaths in Canada: a systematic review.

BACKGROUND: Firearm misuse is common in cases of homicide, suicide and unintentional injury; this is a major public health issue, with societal and economic costs extending beyond the immediate injury or loss of life. We sought to review the evidence on the effectiveness of Canadian legislation in reducing deaths caused by firearms. METHODS: Five databases (PubMed, Embase, CINAHL, Web of Science and Scopus) were searched from inception to May 2021 for studies evaluating the effect of Canadian gun control laws Bill C-51 (1977), Bill C-17 (1991) and Bill C-68 (1995) on rates of firearm-related death. Two reviewers performed article screening independently and in duplicate. We synthesized data using descriptive statistics. The primary outcome of interest was firearm-related mortality rates. Because of study heterogeneity, a meta-analysis was not performed. RESULTS: Overall, 1479 articles were screened, and 18 studies were included. Ten studies examined the effect on homicides, of which 5 reported a reduction during the postlegislation period; 1 study reported evidence of substitution from firearms to other methods of homicide among people aged 15-24 years. Eleven studies evaluated the effect on suicides, with 9 finding a reduction in suicide rates. Eight of these studies reported evidence of substitution from firearms to other suicide methods. Two studies investigated accidental deaths; neither reported any benefit after legislation. INTERPRETATION: Evidence supporting the effectiveness of Canadian firearms legislation in the reduction of homicide and accidental death rates is inconclusive; a decrease in firearm-related suicide rates was observed by most studies, but evidence of method substitution was also identified. Re-evaluation of existing laws may be beneficial to build an improved and effective evidence-based national framework for prevention of gun violence. PROSPERO REGISTRATION: CRD42020192486.

Mandatory gunshot wound reporting in Nova Scotia: a pre-post-evaluation of firearm-related injury rates.

OBJECTIVE: Mandatory gunshot wound reporting laws have been enacted in much of Canada, yet there is a lack of evidence on whether these laws are effective in preventing firearm injuries. Our objective was to determine if the Gunshot Wounds Reporting Act in Nova Scotia had an effect on the number of firearm-related injuries in the province. METHODS: Pre-post-study of major trauma patients in Nova Scotia who sustained a gunshot wound injury before and after enactment of the Gunshot Wounds Reporting Act (Bill 10) in 2008. Data were collected from the Nova Scotia Trauma Registry and the Nova Scotia Medical Examiner Service for a 6-year pre-period (2002-2007) and an 11-year post-period (2009-2019), allowing for a 1-year washout period. Patient characteristics in the pre- and post-periods were compared using t tests and Chi-square analysis. Gunshot wound traumas were analyzed as a time series using the AutoRegressive Integrated Moving Average (ARIMA) model. RESULTS: A total of 722 firearm injuries were observed during the study period (pre-period = 259, post-period = 463). Mean age was 45.2 ± 19.3 years with males accounting for 95.3% (688/722) of cases. The majority of injuries were self-inflicted (65.1%; 470/722). The mean overall annualized rate of firearm injuries was 4.61 per 100,000 population in the pre-period and 4.45 per 100,000 in the post-period (reduction of 3.4%). No linear trends in the annual number of firearm injuries were observed over the study period. ARIMA modelling was an extremely poor predictor for gunshot wound trauma (R2 = 0.012). CONCLUSIONS: Although our findings suggest that there is no association between the Gunshot Wounds Reporting Act and the incidence of firearm injury, it is difficult to draw firm conclusions due to the complexity of this topic. Physicians need to be aware of the legal requirements of mandatory reporting when they encounter patients with gunshot wounds.

RéSUMé: OBJECTIF: Des lois obligatoires sur le signalement des blessures par balle ont été promulguées dans une grande partie du Canada, mais on manque de données probantes sur l'efficacité de ces lois pour prévenir les blessures par balle. Notre objectif était de déterminer si la Gunshot Wounds Reporting Act de la Nouvelle-Écosse a eu un effet sur le nombre de blessures liées aux armes à feu dans la province. MéTHODES: Étude pré-post des patients souffrant de traumatismes majeurs en Nouvelle-Écosse et ayant subi une blessure par balle avant et après la promulgation de la loi sur la déclaration des blessures par balle (projet de loi 10) en 2008. Les données ont été recueillies auprès du Nova Scotia Trauma Registry et du Nova Scotia Medical Examiner Service pour une période de 6 ans avant (2002­2007) et de 11 ans après (2009­2019), en tenant compte d'une période d'élimination d'un an. Les caractéristiques des patients avant et après les périodes ont été comparées à l'aide de tests- t et d'une analyse du chi-carré. Les traumatismes liés aux blessures par balle ont été analysés comme une série chronologique à l'aide du modèle ARIMA (AutoRegressive Integrated Moving Average). RéSULTATS: Au total, 722 blessures par arme à feu ont été observées au cours de la période d'étude (avant la période = 259, après la période = 463). L'âge moyen était de 45,2 ± 19,3 ans, les hommes représentant 95,3% (688/722) des cas. La majorité des blessures étaient auto-infligées (65,1%; 470/722). Le taux global moyen annualisé de blessures par arme à feu était de 4,61 pour 100 000 habitants pendant la période antérieure et de 4,45 pour 100 000 pendant la période postérieure (réduction de 3,4%). Aucune tendance linéaire du nombre annuel de blessures par arme à feu n'a été observée au cours de la période d'étude. Le modèle ARIMA s'est avéré être un très mauvais prédicteur des traumatismes liés aux blessures par balle (R2 = 0,012). CONCLUSIONS: Bien que nos résultats suggèrent qu'il n'y a pas de lien entre la loi sur le signalement des blessures par balle et l'incidence des blessures par arme à feu, il est difficile de tirer des conclusions définitives en raison de la complexité de ce sujet. Les médecins doivent être conscients des obligations légales de déclaration obligatoire lorsqu'ils rencontrent des patients présentant des blessures par balle.

Isolated Tumor Cells in Sentinel Lymph Nodes of Primary Invasive Breast Carcinoma: A Cohort Analysis.

BACKGROUND: The practice of performing routine cytokeratin immunohistochemistry (CK-IHC) on sentinel lymph nodes in early stage invasive breast cancer leads to frequent identification of isolated tumor cells (ITCs), the clinical significance of which remains unclear. After emergence of guidelines that suggested limited clinical utility of ITC detection, routine CK-IHC (rCK-IHC) staining was discontinued at our institution. We studied the rate and clinical utility of ITC detection before and after the discontinuation of rCK-IHC. PATIENTS AND METHODS: We retrospectively reviewed 2 cohorts of 250 consecutive early stage invasive breast cancer (IBC) patients with sentinel lymph node biopsies (SLNBs) in 2010 to 2011 (rCK-IHC) and 2015 to 2016 (selective CK-IHC [sCK-IHC]). Variables abstracted included: tumor histology, tumor size, grade, lymphatic-vascular invasion, hormone receptor expression, HER2 status, and nodal status including ITCs. All cases from the 2015 to 2016 cohort for which sCK-IHC was performed underwent pathology review. A clinical review of treatment decision effect and cost analysis was undertaken. Data were analyzed using descriptive statistics and Fisher exact test. RESULTS: In the rCK-IHC cohort, all 250 cases underwent CK-IHC staining versus 57 cases in the sCK-IHC cohort. There were 23 ITC cases observed in the rCK-IHC cohort compared with 11 in the sCK-IHC cohort (P = .049). Excluding lobular carcinomas, 19 ITC cases were observed with rCK-IHC versus 7 with sCK-IHC (P = .02). ITC detection did not affect adjuvant treatment decision-making and resulted in savings of at least Can$8000. CONCLUSION: Selective rather than routine use of CK-IHC staining for SLNB evaluation in early-stage IBC results in decreased ITC detection without affecting treatment decisions and leads to cost savings.

Incomplete Thyroid Ultrasound Reports for Patients With Thyroid Nodules: Implications Regarding Risk Assessment and Management.

OBJECTIVE: The purpose of this study was to determine the completeness of thyroid ultrasound (US) reports, assess for differences in report interpretation by clinicians, and evaluate for implications in patient care. MATERIALS AND METHODS: We retrospectively reviewed thyroid US examinations performed between January and June 2013 in Nova Scotia, Canada. Baseline examinations that identified a nodule were evaluated for 10 reporting elements. Reports that lacked a comment regarding malignancy risk or a recommendation for biopsy were considered unclassified and were graded by three clinical specialists in accordance with the 2015 American Thyroid Association management guidelines. Interrater agreement was assessed using the Cohen kappa statistic. A radiologist reviewed the images of unclassified nodules, and on the basis of radiologic grading, biopsy rates and pathologic findings were compared between nodules that did and did not warrant biopsy. RESULTS: Of 971 first-time thyroid US studies, 478 detected a nodule. The number of reports lacking a comment on the 10 elements ranged from 154 to 433 (32-91%). A total of 222 nodules (46%) were unclassified, and agreement in assigned grading by the clinical specialists was very poor (κ = 0.07; p < 0.05). According to radiologist grading, only 57 of 127 biopsies were performed on nodules that warranted biopsy, and 16 of 95 biopsies were performed unnecessarily. On the basis of the three clinical specialists' interpretation, 10, 31, and 33 reports were considered too incomplete to assign a grade; 40, 10, and four biopsies would have been unnecessarily ordered; and zero, three, and four cancers would have been missed. CONCLUSION: There is widespread underreporting of established elements in thyroid US reports, and this causes confusion and discrepancy among clinical specialists regarding the risk of malignancy and the need for biopsy.