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OBJECTIVE: Nonadherence to prescribed medication is associated with increased morbidity and mortality as well as the increased use of health services. The main objective of our study was to assess the incidence of prescription-filling and medication adherence in patients discharged from the emergency department (ED). METHODS: This was a prospective, observational study carried out at a Canadian tertiary care ED with an annual census of 69 000. We enrolled a convenience sample of patients being discharged with a prescription. We queried a provincial prescription-dispensing database 2 weeks later to determine whether prescriptions had been filled. We used a standardized follow-up interview to assess adherence and whether or not the patient experienced an adverse drug-related event (ADRE) or an unplanned revisit to an ED or clinic. RESULTS: Of the 301 patients who agreed to participate, follow-up was successful for 258 (85.7%). Fifty-one patients (19.8%, 95% confidence interval [CI] 15.4%-25.1%) failed to fill their discharge prescriptions and 104 (40.3%, 95% CI 34.5%-46.4%) did not adhere to 1 or more medications. Antibiotics were associated with a lower odds ratio (OR) of nonadherence (OR 0.21, 95% CI 0.08-0.52). There was a trend toward increasing nonadherence in patients who reported an ADRE (OR 1.84, 95% CI 0.98-3.48) or had 2 or more medications coprescribed (OR 1.71, 95% CI 0.95-3.09). There was also a trend toward a higher risk of a revisit to an ED or clinic in nonadherent patients (OR 1.75, 95% CI 0.94-3.25). CONCLUSION: Approximately 4 in 10 patients discharged from the ED did not adhere to his or her prescribed medication. Our results suggest that patients who are prescribed antibiotics are more likely to be adherent, and that further evaluation of the associations between nonadherence, ADREs, the coprescription of 2 or more medications and the use of health services is warranted. [ABSTRACT FROM AUTHOR]

Objective: For many patients with addiction and other substance problems, the emergency department (ED) is the sole provider of medical care. This study sought to determine the prevalence and characteristics of substance-related medical problems in ED patients, as defined by documentation in the medical record. We also sought to compare the ED resource use (length of ED stay and number of revisits) of patients with and without substance problems. Methods: Trained evaluators using explicit criteria reviewed all ED charts during a 6-week period at a Canadian tertiary care teaching centre. Data was collected on demographics, documentation of problematic substance use and whether the ED visit was due to substance problems. Using a computerized database, we determined how many patients with and without substance problems had 1 or more subsequent ED visits during the 1-year period from Sept. 1, 2002, to Aug. 31, 2003. Results: Of 6064 visits made by 5194 patients, 6026 visits (99.4%) representing 5188 patients (99.9%) were captured for review. Of those visits, 674 (11.2%, 95% confidence interval [CI] 10.4%-12.0%), made by 600 patients, had documentation of problematic substance use and 521 visits (8.6%, 95% CI 7.9%-9.4%) by 469 patients were caused by substance problems. The mean age of patients with a visit due to a substance problem was 39.2 years, compared with 48.5 years for those with other visits (p < 0.001). The admission rate for substance-related visits was 25.3%, compared with 17.6% for other visits (p < 0.001). For discharged patients, the median length of the ED visit owing to substance-related problems lasted 232 minutes (IQR [interquartile range] 267 min), compared with 164 minutes (IQR 167 min) for other visits (p < 0.001). In 1 year of follow-up, 161 of 600 patients (26.8%) with a substance problem made 466 revisits (mean 0.78 revisits/patient), compared with 975 of 4588 patients (21.3%) without a substance problem who made a total of 2150 revisits (mean 0.47 revisits/patient, p < 0.001). Conclusion: Substance problems contribute significantly to ED visits, hospital admissions and duration of ED stay at a tertiary centre. It is likely that our methodology underestimates the scope of the problem and that a universal screening program would find a higher prevalence. The magnitude of this problem supports the need for an interdisciplinary identification and intervention program for ED patients with substance-related issues. [ABSTRACT FROM AUTHOR]

Background: The osmole gap is used routinely as a screening test for the presence of exogenous osmotically active substances, such as the toxic alcohols ethylene glycol and methanol, particularly when the ability to measure serum concentrations of the substances is not available. The objectives of this study were: 1) to measure the diagnostic accuracy of the osmole gap for screening for ethylene glycol and methanol exposure, and 2) to identify whether a recently proposed modification of the ethanol coefficient affects the diagnostic accuracy.Methods: Electronic laboratory records from two tertiary-care hospitals were searched to identify all patients for whom a serum ethylene glycol and methanol measurement was ordered between January 1, 1996 and March 31, 2002. Cases were eligible for analysis if serum sodium, blood urea nitrogen, glucose, ethanol, ethylene glycol, methanol, and osmolality were measured simultaneously. Serum molarity was calculated using the Smithline and Gardner equation and ethanol coefficients of 1 and 1.25 mOsm/mM. The diagnostic accuracy of the osmole gap was evaluated for identifying patients with toxic alcohol levels above the recommended threshold for antidotal therapy and hemodialysis using receiver-operator characteristic curves, likelihood ratios, and positive and negative predictive values.Results: One hundred and thirty-one patients were included in the analysis, 20 of whom had ethylene glycol or methanol serum concentrations above the threshold for antidotal therapy. The use of an ethanol coefficient of 1.25 mOsm/mM yielded higher specificities and positive predictive values, without affecting sensitivity and negative predictive values. Employing an osmole gap threshold of 10 for the identification of patients requiring antidotal therapy resulted in a sensitivity of 0.9 and 0.85, and a specificity of 0.22 and 0. 5, with equations 1 and 2 respectively. The sensitivity increased to 1 for both equations for the identification of patients requiring dialysis.Conclusion: In this sample, an osmole gap threshold of 10 has a sensitivity and negative predictive value of 1 for identifying patients for whom hemodialysis is recommended, independent of the ethanol coefficient applied. In patients potentially requiring antidotal therapy, applying an ethanol coefficient of 1.25 resulted in a higher specificity and positive predictive value without compromising the sensitivity. [ABSTRACT FROM AUTHOR]

Background: Patient-initiated or "before medically advised" (BMA) hospital discharge is more common among people who use drugs. Transitions of care can be destabilizing and might increase the risk of subsequent illicit drug overdose., Objectives: This study sought to evaluate whether BMA discharge is associated with an increased risk of subsequent drug overdose (primary objective) and whether physician-advised discharge is associated with an increased risk of subsequent drug overdose (secondary objective)., Methods: We performed a case-crossover analysis of population-based linked administrative health data for individuals experiencing an overdose between 2016 and 2019 in British Columbia, Canada. Using conditional logistic regression, we compared the likelihood of hospital discharge in the 28 days before overdose (the "pre-overdose interval") to the likelihood of hospital discharge in two self-matched 28-day control intervals ending 26 and 52 weeks before overdose., Results: Over the 3.5-year study interval, 235 of 27,584 (0.9%) pre-overdose intervals and 189 of 55,168 (0.3%) control intervals included a BMA discharge, suggesting that BMA discharge was associated with a twofold increase in the risk of subsequent drug overdose (adjusted odds ratio [aOR], 2.08; 95% confidence interval [95% CI], 1.68-2.58; p < 0.001). Physician-advised hospital discharge was also a risk factor for subsequent overdose, occurring in 1350 of 27,584 (4.9%) pre-overdose intervals and 1625 of 55,168 (2.9%) control intervals (aOR, 1.39; 95% CI, 1.27-1.52; p < .001)., Conclusions: Both BMA and physician-advised hospital discharge are independently associated with transient increases in the risk of subsequent illicit drug overdose. Better in-hospital treatment of substance use disorder and novel means of post-discharge outreach should be deployed to reduce this risk., (© 2024 The Author(s). Journal of Hospital Medicine published by Wiley Periodicals LLC on behalf of Society of Hospital Medicine.)

Background: Limited empirical evidence informs driving restrictions after implantable cardioverter-defibrillator (ICD) implantation. We sought to evaluate real-world motor vehicle crash risks after ICD implantation., Methods: We performed a retrospective cohort study using 22 years of population-based health and driving data from British Columbia, Canada (2019 population: 5 million). Individuals with a first ICD implantation between 1997 and 2019 were age and sex matched to three controls. The primary outcome was involvement as a driver in a crash that was attended by police or that resulted in an insurance claim. We used survival analysis to compare crash risk in the first 6 months after ICD implantation to crash risk during a corresponding 6-month interval among controls., Results: A crash occurred prior to a censoring event for 296 of 9373 individuals with ICDs and for 1077 of 28 119 controls, suggesting ICD implantation was associated with a reduced risk of subsequent crash (crude incidence rate, 8.5 vs 10.5 crashes per 100 person-years; adjusted HR (aHR), 0.71; 95% CI 0.61 to 0.83; p<0.001). Results were similar after stratification by primary versus secondary prevention ICD. Relative to controls, ICD patients had more traffic contraventions in the 3 years prior to ICD implantation but fewer contraventions in the 6 months after implantation, suggesting individuals reduced their road exposure (hours or miles driven per week) or drove more conservatively after ICD implantation., Conclusions: Crash risk is lower in the 6 months after ICD implantation than among matched controls, likely because individuals reduced their road exposure in order to comply with contemporary postimplantation driving restrictions. Policymakers might consider liberalisation of postimplantation driving restrictions while monitoring crash rates., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: A substantial number of hospital admissions end in patient-initiated departure before medical treatment is complete. Whether "before medically advised" (BMA) discharge increases the risk of subsequent drug overdose remains uncertain., Methods: We performed a retrospective cohort study using administrative health data from a 20% random sample of residents of British Columbia, Canada. We focused on nonelective, nonobstetric hospital stays occurring between 2015 and 2019. We used survival analysis to compare the rate of fatal or nonfatal illicit drug overdose in the first 30 days after BMA discharge versus the rate after physician-advised discharge., Results: Overall, 6440 of 189 808 (3.4%) hospital stays ended in BMA discharge. Among 820 overdoses occurring in the first 30 days after any hospital discharge, 755 (92%) involved patients with a history of substance use disorder. Unadjusted overdose rates were 10-fold higher after BMA discharge than after physician-advised discharge, and BMA discharge was associated with subsequent overdose even after adjustment for potential confounders (crude incidence, 2.8% v. 0.3%; adjusted hazard ratio [HR] 1.58; 95% confidence interval [CI] 1.31-1.89). Before medically advised discharge was associated with increases in subsequent emergency department visits (adjusted HR 1.92; 95% CI 1.83-2.02) and unplanned hospital readmissions (adjusted HR 2.07; 95% CI 1.96-2.19), but there was no significant association with the uncommon outcomes of fatal overdose and all-cause mortality., Interpretation: Before medically advised departure is associated with an increased risk of drug overdose in the first 30 days after discharge. Improved treatment of substance use disorder, expanded access to overdose prevention services, and new means of postdeparture outreach should be explored to reduce this risk., Competing Interests: Competing interests:: Jeffrey Brubacher reports receiving grants from the Canadian Institutes of Health Research (CIHR), Public Safety Canada, Transport Canada, British Columbia Ministry of Public Safety and Solicitor General, and Saskatchewan Government Insurance. Alexis Crabtree is an employee of the BC Centre for Disease Control, an agency of the BC Provincial Health Services Authority. Jessica Moe reports receiving grants or contracts from the Vancouver Physician Staff Association, the Canadian Association of Emergency Physicians/Schwartz-Reisman Emergency Medicine Institute, the Health Canada Substance Use and Addictions Program, CIHR (team grant: Partnerships for Cannabis Policy Evaluation; project grants: Opioid Overdose-Related Cardiac Arrest, Evaluating Microdosing in Emergency Departments, and Drug Overdose after Departure from Hospital Against Medical Advice; training grants: Clinical Trials Training Platforms), and the BC Centre for Disease Control (STARTS grant). Dr. Moe has also received the Vancouver Coastal Health Research Institute Mentored Clinician Scientist Award. Amanda Slaunwhite reports receiving project grant funds from Health Canada, CIHR, the Public Health Agency of Canada, the Community Action Initiative, the province of British Columbia, and Michael Smith Health Research BC (all payments made to the University of British Columbia or Provincial Health Services Authority for staff, trainee, or other project costs). Dr. Slaunwhite has also served on the Board of Directors of Unlocking the Gates and Moms Stop the Harm (unpaid). John Staples reports receiving salary support from a Michael Smith Health Research BC Health Professional–Investigator Award and the UBC Division of General Internal Medicine’s Academic Investment Fund. No other competing interests were declared., (© 2024 CMA Impact Inc. or its licensors.)

Background: Unplanned hospital readmissions are associated with adverse patient outcomes and substantial healthcare costs. It remains unknown whether physician financial incentives for enhanced discharge planning can reduce readmission risk., Methods: In 2012, policymakers in British Columbia, Canada, introduced a $75 fee-for-service physician payment to incentivize enhanced discharge planning (the "G78717" fee code). We used population-based administrative health data to compare outcomes among G78717-exposed and G78717-unexposed patients. We identified all nonelective hospitalizations potentially eligible for the incentive over a 5-year study interval. We examined the composite risk of unplanned readmission or death and total direct healthcare costs accrued within 30 days of discharge. Propensity score overlap weights and adjustment were used to account for differences between exposed and unexposed patients., Results: A total of 5262 of 24,787 G78717-exposed and 28,096 of 136,541 unexposed patients experienced subsequent unplanned readmission or death, suggesting exposure to the G78717 incentive did not reduce the risk of adverse outcomes after discharge (crude percent, 21.1% vs 20.6%; adjusted odds ratio, 0.97; 95% CI, 0.93-1.01; P = .23). Mean direct healthcare costs within 30 days of discharge were $3082 and $2993, respectively (adjusted cost ratio, 1.00; 95% CI, 0.95-1.05; P = .93)., Conclusions: A physician financial incentive that encouraged enhanced hospital discharge planning did not reduced the risk of readmission or death, and did not significantly decrease direct healthcare costs. Policymakers should consider the baseline prevalence and effectiveness of enhanced discharge planning, the magnitude and design of financial incentives, and whether auditing of incentivized activities is required when implementing similar incentives elsewhere., Trial Registration: ClinicalTrials.gov ID, NCT03256734., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Persistent symptoms are common after a mild traumatic brain injury (mTBI). The Post-Concussion Symptoms (PoCS) Rule is a newly developed clinical decision rule for the prediction of persistent post-concussion symptoms (PPCS) 3 months after an mTBI. The PoCS Rule includes assessment of demographic and clinical characteristics and headache presence in the emergency department (ED), and follow-up assessment of symptoms at 7 days post-injury using two thresholds (lower/higher) for symptom scoring. We examined the PoCS Rule in an independent sample. We analyzed a clinical trial that recruited participants with mTBI from EDs in Greater Vancouver, Canada. The primary analysis used data from 236 participants, who were randomized to a usual care control group, and completed the Rivermead Postconcussion Symptoms Questionnaire at 3 months. The primary outcome was PPCS, as defined by the PoCS authors. We assessed the overall performance of the PoCS rule (area under the receiver operating characteristic curve [AUC]), sensitivity, and specificity. More than 40% of participants (median age 38 years, 59% female) reported PPCS at 3 months. Most participants (88%) were categorized as being at medium risk based on the ED assessment, and a majority were considered as being at high risk according to the final PoCS Rule (81% using a lower threshold and 72% using a higher threshold). The PoCS Rule showed a sensitivity of 93% (95% confidence interval [CI], 88-98; lower threshold) and 85% (95% CI, 78-92; higher threshold), and a specificity of 28% (95% CI, 21-36) and 37% (95% CI, 29-46), respectively. The overall performance was modest (AUC 0.61, 95% CI 0.59, 0.65). In conclusion, the PoCS Rule was sensitive for PPCS, but had a low specificity in our sample. Follow-up assessment of symptoms can improve risk stratification after mTBI.

Objective: To examine the relationship between schizophrenia, antipsychotic medication adherence and driver responsibility for motor vehicle crash., Design: Retrospective observational cohort study using 20 years of population-based administrative health and driving data., Setting: British Columbia, Canada., Participants: Licensed drivers who were involved in a police-attended motor vehicle crash in British Columbia over a 17-year study interval (2000-16)., Exposures: Incident schizophrenia was identified using hospitalisation and physician services data. Antipsychotic adherence was estimated using prescription fill data to calculate the 'medication possession ratio' (MPR) in the 30 days prior to crash., Primary Outcome Measures: We deemed drivers 'responsible' or 'non-responsible' for their crash by applying a validated scoring tool to police-reported crash data. We used logistic regression to evaluate the association between crash responsibility and exposures of interest., Results: Our cohort included 808 432 drivers involved in a police-attended crash and for whom crash responsibility could be established. In total, 1689 of the 2551 drivers with schizophrenia and 432 430 of the 805 881 drivers without schizophrenia were deemed responsible for their crash, corresponding to a significant association between schizophrenia and crash responsibility (66.2% vs 53.7%; adjusted OR (aOR), 1.67; 95% CI, 1.53 to 1.82; p<0.001). The magnitude of this association was modest relative to established crash risk factors (eg, learner license, age ≥65 years, impairment at time of crash). Among the 1833 drivers with schizophrenia, near-optimal antipsychotic adherence (MPR ≥0.8) in the 30 days prior to crash was not associated with lower crash responsibility (aOR, 1.04; 95% CI, 0.83 to 1.30; p=0.55)., Conclusions: Crash-involved drivers with schizophrenia are more likely to be responsible for their crash, but the magnitude of risk is similar to socially acceptable risk factors such as older age or possession of a learner license. Contemporary driving restrictions for individuals with schizophrenia appear to adequately mitigate road risks, suggesting more stringent driving restrictions are not warranted., Competing Interests: Competing interests: WH is a consultant to Translational Life Sciences, AbbVie, Newron, and Otsuka., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Health-related quality of life (HRQoL) should be considered when evaluating the burden of road trauma (RT) injuries. This study aimed to identify distinct HRQoL trajectories following minor to severe RT injury and determine characteristics of trajectory membership., Methods: This prospective inception cohort study recruited 1480 RT survivors from three emergency departments in British Columbia, Canada (July 2018 - March 2020). HRQoL outcome was measured with the Short Form 12 survey (SF-12) and the 5-level version of the EuroQol instrument (EQ-5D-5L) at baseline (pre-injury) and at 2, 4, 6, and 12 months post-injury. Potential predictors of outcome trajectory included sociodemographic, psychological, medical, crash, and injury factors collected at baseline. We used a latent growth mixture model to identify distinct recovery trajectories and multinomial logistic regression to determine predictors of trajectory membership., Results: Three distinct HRQoL trajectories were identified for SF-12 subscales and EQ-5D-5L measures: Low/Moderate-Stable, High-Large decline, and High-Slight decline. Participants in the Low/Moderate-Stable trajectory had persistent low to moderate HRQoL before and after the injury. Those in the High-Large decline trajectory had good pre-injury HRQoL followed by persistently decreased HRQoL afterwards. The High-Slight decline trajectory was characterized by good pre-injury HRQoL and only a slight decline afterwards. Participants in the Low/Moderate-Stable and High-Large decline trajectories were considered at risk of permanently poor HRQoL following RT injury given their low HRQoL over a long period of time. Characteristics that placed participants in the Low/Moderate-Stable trajectory were older age, female gender, poor pre-injury health (medical comorbidity, prescribed medication use, complaints in the injured body area(s)), pre-injury somatic symptoms, pain catastrophizing or psychological distress, injury severity (ISS) and injury pain. Patients with head injury were less likely to be in the Low/Moderate-Stable trajectory. Risk factors for membership in the High-Large decline trajectory included older age (for physical HRQoL), younger age (for mental HRQoL), female gender, living alone, pre-injury psychological distress, ISS, injury pain, no expectations for a fast recovery, as well as head injuries, spine/back injuries or lower extremity injuries., Conclusions: This study highlighted the heterogeneity of HRQoL trajectories following RT injury and the importance of considering differences between characteristics of survivors. In addition to injury type and severity, outcome is related to demographic factors, pre-injury health and pre-injury psychological factors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Road trauma (RT) survivors have reduced health-related quality of life (HRQoL). We identified phases and predictors of HRQoL change following RT injury., Methods: In a prospective cohort study of 1480 Canadian RT survivors aged 16 to 103 years (July 2018 - March 2020), physical component (PCS) and mental component (MCS) summary scores from the SF-12v2 were measured pre-injury and 2, 4, 6, and 12 months post-injury and their trajectories were analyzed with piecewise latent growth curve modeling. Potential predictors of HRQoL changes included sociodemographic, psychological, medical, and trauma-related factors., Results: PCS and MCS scores worsened from pre-injury to 2-months (phase 1) and then improved (phase 2), but never regained baseline values. Older age, somatic symptoms and pain catastrophizing were associated with lower preinjury PCS and MCS scores. Psychological distress was associated with lower preinjury MCS scores and higher preinjury PCS scores. Phase 1 PCS scores decreased most in females, participants with fewer pre-injury somatic symptoms and those without expectations for fast recovery. Phase 1 MCS decreases were associated with younger age, female sex, living alone, lower psychological distress, lack of expectation for fast recovery and higher injury pain. In phase 2, MCS improved most in participants not using recreational drugs; PCS improved most in participants with higher education and longer recovery expectations., Limitations: There may be recall bias with reporting pre-injury HRQoL. Selection bias is possible., Conclusions: Many factors influence HRQoL following RT. These findings may inform measures to minimize HRQoL reduction following RT and speed up subsequent recovery., Competing Interests: Declaration of competing interest None, (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Injury-related disability following road trauma is a major public health concern. Unfortunately, outcome following road trauma and risk factors for poor recovery are inadequately studied, especially for road trauma survivors with minor injuries that do not require hospitalization., Objectives: This manuscript reports 12-month recovery outcomes for a large cohort of road trauma survivors., Methods: This was a prospective, observational inception cohort study of 1,480 road trauma survivors recruited between July 2018 and March 2020 from 3 trauma centres in British Columbia, Canada. Participants were aged ≥16 years and arrived in a participating emergency department within 24 h of a motor vehicle collision. Data on baseline health and injury severity were collected from structured interviews and medical records. Outcome measures, including the SF-12, were collected during follow-up interviews at 2, 4, 6 and 12 months. Predictors of recovery outcomes were identified using Cox proportional hazards models and summarized using hazard ratios., Results: Only 42 % of participants self-reported full recovery and only 66 % reported a return to usual daily activities. Females, older individuals, pedestrians, and those who required hospital admission had a poorer recovery than other groups. Similar patterns were observed for the SF-12 physical component. For the SF-12 mental component, no significant differences were observed between participants admitted to hospital and those discharged home from the ED. Return to work was reported by 77 % of participants who had a paying job at baseline, with no significant differences between sex and age groups., Conclusions: In a large cohort of road trauma survivors, under half self-reported full recovery one year after the injury. Poor mental health recovery was observed in both participants admitted to hospital and those discharged home from the ED. This finding may indicate a need for early intervention and continued mental health monitoring for all injured individuals, including for those with less serious injuries., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Background: Impaired driving is a public health issue, yet little is known concerning the prevalence of substance use in drivers involved in off-road vehicle crashes. The goal of the present study was to describe the demographics and prevalence of alcohol and drug use in drivers of off-road vehicle crashes., Methods: In this observational substudy, we collected clinical and toxicological data on all moderately or severely injured off-road vehicle drivers who had blood samples obtained within 6 h of the crash. Clinical data were extracted from patients' medical charts and toxicology analyses were performed for blood alcohol, cannabinoids, recreational drugs, and impairing medications., Results: Thirty-three injured drivers met the inclusion criteria. The mean age was 37.6 ± 13.4 years and 79% were male. Blood alcohol was detected in 58% of drivers and 42% of these were above the legal limit. Tetrahydrocannabinol was positive in 12% of drivers, and 18% were positive for recreational drugs. Opiates were detected in 21% of drivers. Overall, 85% were positive for at least one substance and 39% tested positive for multiple substances., Conclusion: This study presents the first evidence of alcohol and drug use in off-road vehicle drivers after cannabis legalization in Canada. Our results show that over half of drivers in off-road vehicle crashes test positive for alcohol and 30% tested positive for THC, cocaine, or amphetamines. Opiates are also commonly detected in off-road vehicle drivers. Emergency department (ED) visits resulting from drug driving of off-road vehicles serve as an opportunity for screening, initiating treatment, and connecting patients to interventions for substance use disorders., (© 2024. The Author(s), under exclusive licence to Canadian Association of Emergency Physicians (CAEP)/ Association Canadienne de Médecine d'Urgence (ACMU).)

Background: Substance use-related emergency department (ED) visits have increased substantially in North America. Screening for substance use in EDs is recommended; best approaches are unclear. This systematic review synthesizes evidence on diagnostic accuracy of ED screening tools to detect harmful substance use., Methods: We included derivation or validation studies, with or without comparator, that included adult (≥ 18 years) ED patients and evaluated screening tools to identify general or specific substance use disorders or harmful use. Our search strategy combined concepts Emergency Department AND Screening AND Substance Use. Trained reviewers assessed title/abstracts and full-text articles for inclusion, extracted data, and assessed risk of bias (QUADAS-2) independently and in duplicate. Reviewers resolved disagreements by discussion. Primary investigators adjudicated if necessary. Heterogeneity precluded meta-analysis. We descriptively summarized results., Results: Our search strategy yielded 2696 studies; we included 33. Twenty-one (64%) evaluated a North American population. Fourteen (42%) applied screening among general ED patients. Screening tools were administered by research staff (n = 21), self-administered by patients (n = 10), or non-research healthcare providers (n = 1). Most studies evaluated alcohol use screens (n = 26), most commonly the Alcohol Use Disorders Identification Test (AUDIT; n = 14), Cut down/Annoyed/Guilty/Eye-opener (CAGE; n = 13), and Rapid Alcohol Problems Screen (RAPS/RAPS4/RAPS4-QF; n = 12). Four studies assessing six tools and screening thresholds for alcohol abuse/dependence in North American patients (AUDIT ≥ 8; CAGE ≥ 2; Diagnostic and Statistical Manual of Mental Disorders, 4th Edition [DSM-IV-2] ≥ 1; RAPS ≥ 1; National Institute on Alcohol Abuse and Alcoholism [NIAAA]; Tolerance/Worry/Eye-opener/Amnesia/K-Cut down [TWEAK] ≥ 3) reported both sensitivities and specificities ≥ 83%. Two studies evaluating a single alcohol screening question (SASQ) (When was the last time you had more than X drinks in 1 day?, X = 4 for women; X = 5 for men) reported sensitivities 82-85% and specificities 70-77%. Five evaluated screening tools for general substance abuse/dependence (Relax/Alone/Friends/Family/Trouble [RAFFT] ≥ 3, Drug Abuse Screening Test [DAST] ≥ 4, single drug screening question, Alcohol, Smoking and Substance Involvement Screening Test [ASSIST] ≥ 42/18), reporting sensitivities 64%-90% and specificities 61%-100%. Studies' risk of bias were mostly high or uncertain., Conclusions: Six screening tools demonstrated both sensitivities and specificities ≥ 83% for detecting alcohol abuse/dependence in EDs. Tools with the highest sensitivities (AUDIT ≥ 8; RAPS ≥ 1) and that prioritize simplicity and efficiency (SASQ) should be prioritized., (© 2024. The Author(s).)

Background: Among individuals with recent syncope, recurrence of syncope while driving might incapacitate a driver and cause a motor vehicle crash. Current driving restrictions assume that some forms of syncope transiently increase crash risk. We evaluated whether syncope is associated with a transient increase in crash risk., Methods: We performed a case-crossover analysis of linked administrative health and driving data from British Columbia, Canada (2010 to 2015). We included licensed drivers who visited an emergency department with "syncope and collapse" and who were involved as a driver in an eligible motor vehicle crash, both within the study interval. Using conditional logistic regression, we compared the rate of emergency visits for syncope in the 28 days before crash (the "pre-crash interval") with the rate of emergency visits for syncope in 3 self-matched 28-day control intervals (ending 6, 12, and 18 months before the crash)., Results: Among eligible crash-involved drivers, 47 of 3026 pre-crash intervals and 112 of 9078 control intervals had emergency visits for syncope, indicating syncope was not significantly associated with subsequent crash (1.6% vs 1.2%; adjusted odds ratio [OR], 1.27; 95% confidence interval [CI], 0.90-1.79; P = 0.18). There was no significant association between syncope and crash in subgroups at higher risk for adverse outcomes after syncope (eg, age > 65 years, cardiovascular disease, cardiac syncope)., Conclusions: In the context of prevailing modifications of driving behaviour after syncope, an emergency department visit for syncope did not transiently increase the risk of subsequent traffic collision. Overall crash risks after syncope appear to be adequately addressed by current driving restrictions., (Copyright © 2023 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Background: Administrative health data and cardiac device registries can be used to empirically evaluate outcomes and costs after implantable cardioverter defibrillator (ICD) implantation. These datasets often have incomplete information on the indication for implantation (primary vs secondary prevention of sudden cardiac death)., Methods: We used 16 years of population-based cardiac device registry and administrative health data from British Columbia, Canada, to derive and internally validate statistical models that predict the likely indication for ICD implantation. We used chart review data as the reference standard for ICD indication in the Cardiac Device Registry database (CDR; 2004-2012 [Cardiac Services BC]) and nonmissing indication as the reference standard in the Heart Information System registry database (HEARTis; 2013-2019 [Cardiac Services BC]). We created 3 logistic regression prediction models in each database: one using only registry data, one using only administrative data, and one using both registry and administrative data. We assessed the predictive performance of each model using standard metrics after optimism correction with 200 bootstrap resamples., Results: Models that used registry data alone demonstrated excellent predictive performance (sensitivity ≥ 89%; specificity ≥ 87%). Models that used only administrative data performed well (sensitivity ≥ 84%; specificity ≥ 70%). Models that used both registry and administrative data showed modest gains over those that used registry data alone (sensitivity ≥ 90%; specificity ≥ 89%)., Conclusions: Administrative health data and cardiac device registry data can distinguish secondary prevention ICDs from primary prevention ICDs with acceptable sensitivity and specificity. Imputation of missing ICD indication might make these data resources more useful for research and health system monitoring., (© 2024 The Authors.)

Study Objective: Syncope that occurs while driving can result in a motor vehicle crash. Whether individuals with a prior syncope-related crash exhibit an exceptional risk of subsequent crash remains uncertain., Methods: We performed a population-based retrospective observational study of patients diagnosed with 'syncope and collapse' at any of 6 emergency departments in British Columbia, Canada (2010 to 2015). Data were obtained from chart abstraction, administrative health records, insurance claims and police crash reports. We compared crash-free survival among individuals with crash-associated syncope (a crash and an emergency visit for syncope on the same date) to that among controls with syncope alone (no crash on date of emergency visit for syncope)., Results: In the year following their index emergency visit, 13 of 63 drivers with crash-associated syncope and 852 of 9,160 controls with syncope alone experienced a subsequent crash as a driver (crash risk 21% versus 9%). After accounting for censoring and potential confounders, crash-associated syncope was not associated with a significant increase in the risk of subsequent crash (adjusted hazard ratio [aHR] 1.38, 95% confidence interval [CI] 0.78 to 2.47). Individuals with crash-associated syncope were 31-fold more likely to have physician driving advice documented during their index visit (prevalence ratio 31.0, 95% CI, 21.3 to 45.1). In the subgroup without documented driving advice, crash-associated syncope was associated with a significant increase in subsequent crash risk (aHR 1.88, 95% CI 1.06 to 3.36)., Conclusions: Crash risk after crash-associated syncope appears similar to crash risk after syncope alone., (Copyright © 2023 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.)

Importance: Epidemiological studies have found that cannabis increases the risk of a motor vehicle collision. Cannabis use is increasing in older adults, but laboratory studies of the association between cannabis and driving in people aged older than 65 years are lacking., Objective: To investigate the association between cannabis, simulated driving, and concurrent blood tetrahydrocannabinol (THC) levels in older adults., Design, Setting, and Participants: Using an ecologically valid counterbalanced design, in this cohort study, regular cannabis users operated a driving simulator before, 30 minutes after, and 180 minutes after smoking their preferred legal cannabis or after resting. This study was conducted in Toronto, Canada, between March and November 2022 with no follow-up period. Data were analyzed from December 2022 to February 2023., Exposures: Most participants chose THC-dominant cannabis with a mean (SD) content of 18.74% (6.12%) THC and 1.46% (3.37%) cannabidiol (CBD)., Main Outcomes and Measures: The primary end point was SD of lateral position (SDLP, or weaving). Secondary outcomes were mean speed (MS), maximum speed, SD of speed, and reaction time. Driving was assessed under both single-task and dual-task (distracted) conditions. Blood THC and metabolites of THC and CBD were also measured at the time of the drives., Results: A total of 31 participants (21 male [68%]; 29 White [94%], 1 Latin American [3%], and 1 mixed race [3%]; mean [SD] age, 68.7 [3.5] years), completed all study procedures. SDLP was increased and MS was decreased at 30 but not 180 minutes after smoking cannabis compared with the control condition in both the single-task (SDLP effect size [ES], 0.30; b = 1.65; 95% CI, 0.37 to 2.93; MS ES, -0.58; b = -2.46; 95% CI, -3.56 to -1.36) and dual-task (SDLP ES, 0.27; b = 1.75; 95% CI, 0.21 to 3.28; MS ES, -0.47; b = -3.15; 95% CI, -5.05 to -1.24) conditions. Blood THC levels were significantly increased at 30 minutes but not 180 minutes. Blood THC was not correlated with SDLP or MS at 30 minutes, and SDLP was not correlated with MS. Subjective ratings remained elevated for 5 hours and participants reported that they were less willing to drive at 3 hours after smoking., Conclusions and Relevance: In this cohort study, the findings suggested that older drivers should exercise caution after smoking cannabis.

Objective: The purpose of this study was to explore various tests of impairment that could potentially be added to the Standardized Field Sobriety Test (SFST) to enhance its sensitivity to identify drivers whose abilities are adversely affected by cannabis., Methods: An observational study was conducted in which participants were invited to use their own cannabis at the research facility. Once prior to cannabis use and at four times during the 150 min after cannabis use, participants performed the three tests of the Standardized Field Sobriety Test (SFST) (i.e., Horizontal Gaze Nystagmus, Walk and Turn, and One Leg Stand) as well as the Modified Romberg Balance and Finger to Nose tests. In addition, assessments were made of physiological indicators (i.e., eyelid, leg and body tremors, rebound dilation, lack of convergence) and vital signs (pulse, blood pressure and body temperature). Participants also completed a digit-symbol substitution task at each testing interval. With the exception of vital signs and the digit symbol task, all tests and assessments were administered and scored by certified Drug Recognition Experts using the standard procedures of the Drug Evaluation and Classification Program., Results: Twenty minutes after vaping cannabis (mean THC concentration = 6.34 ng/mL), participants displayed performance deficits on a variety of tasks; 67% met the criterion for suspected impairment on the SFST. Addition of the Finger-to-Nose (FTN) test along with observations of head movements and jerks (HMJ) increased the percentage of participants who met the criterion for suspected impairment by 33% and improved the sensitivity of the test from 0.67 to 0.88., Conclusions: The results of this study support supplementing the SFST with the Finger-to-Nose test and observations of HMJ to assist in the detection of drivers who are adversely affected by the use of cannabis. The observational study design and the use of assessors who were not blinded as to the use of cannabis by participants limits the strength of the evidence. Further research, including randomized trials and field studies of drivers, is required to confirm and validate this enhanced version of the SFST.

Introduction: Active transport (AT) is promoted by urban planners and health officials for its environmental, economic and societal benefits and its uptake is increasing. Unfortunately, AT users can be injured or killed due to falls or collisions. Active transport injury (ATI) prevention efforts are hindered by limited research on the circumstances, associated infrastructure, injury pattern, severity and outcome of ATI events. This study seeks to address these knowledge gaps by identifying built environment features associated with injury and risk factors for a poor outcome following ATI., Methods and Analysis: This prospective observational study will recruit an inception cohort of 2000 ATI survivors, including pedestrians, cyclists and micromobility users aged 16 years and older who arrive at a participating emergency department within 48 hours of sustaining an ATI. Baseline interviews capture demographic and socioeconomic information, pre-injury health and functional status, as well as circumstances of the injury event and recovery expectations. Follow-up interviews at 2, 4, 6 and 12 months postinjury (key stages of recovery) use standardised health-related quality of life tools to determine physical and mental health outcomes, functional recovery and healthcare resource use and lost productivity costs., Ethics and Dissemination: The Active Transportation Injury Circumstances and Outcome Study is approved by our institutional research ethics board and the research ethics boards of all participating sites. This study aims to provide healthcare providers with knowledge of risk factors for poor outcome following ATI with the goal of improving patient management. Additionally, this study will provide insight into the circumstances of ATI events including built environment features and how those circumstances relate to recovery outcomes. This information can be used to inform city engineers and planners, policymakers and public health officials to plan roadway design and injury prevention policy., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Road trauma (RT) is a major public health problem that often results in prolonged absenteeism from work. Limited evidence suggests that recovery after RT is associated with automobile insurance compensation schemes. In May 2021, British Columbia, Canada switched from fault-based to no-fault auto-insurance coverage. This manuscript presents the protocol for a planned evaluation of that natural experiment: We will evaluate the impact of changing automobile insurance schemes on return to work following RT., Methods and Analysis: The evaluation will use a before-after design to analyse auto-insurance claims (1 April 2019 to 30 April 2024) in order to compare recovery of claimants with non-catastrophic injuries who filed claims under the no-fault insurance scheme to that of those who filed claims under the previous system. Claimants will be followed from date of injury until they return to work or have been followed for 6 months (right-censored). We will perform sensitivity analyses to examine the robustness of our findings. First, we will exclude injuries that occurred during the COVID-19 provincial State of Emergency. Second, we will use propensity score methods rather than conventional covariate adjustment to address potential imbalance between characteristics of claimants pre-change and post-change. Finally, as the implementation effect may have a heterogeneous association with time off work, we will use quantile regression with right-censoring at 6 months to model differences in return to work at the 25th, 50th, 75th and 90th percentiles., Ethics and Dissemination: The study uses de-identified data and is approved by the University of British Columbia Clinical Research Ethics Board (H20-03644). This research is funded by the Insurance Corporation of British Columbia (ICBC). Findings will be published in the peer-reviewed literature and summarised in a report prepared for ICBC. We anticipate that our findings will inform policy decisions in other jurisdictions considering switching to no-fault auto-insurance schemes., Competing Interests: Competing interests: This research is funded by a research contract with the Insurance Corporation of British Columbia (ICBC). ICBC may object to a proposed Presentation or Publication on the grounds that it contains Restricted Information or Confidential Information that was disclosed to the Institution (ie, The University of British Columbia) by ICBC. If ICBC makes such objection, the Institution will ensure that the Research Team removes such Restricted Information or Confidential Information, as applicable, immediately from the proposed Presentation or Publication, after which the Institution can publish or present. Importantly, ICBC does NOT have authority to delay or prevent publication or presentation of any findings by the Research Team., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Road trauma is a major public health concern, often resulting in reduced health-related quality of life and prolonged absenteeism from work even after so-called 'minor' injuries that do not result in hospitalization. This manuscript compares pre-injury health, sociodemographic characteristics and injury details between age, sex, and road user categories in a cohort of 1,480 road trauma survivors., Methods: This was a prospective observational inception cohort study of road trauma survivors recruited between July 2018 and March 2020 from three trauma centres in British Columbia, Canada. Participants were aged ≥ 16 years and arrived in a participating emergency department within 24 h of involvement in a motor vehicle collision. Data were collected from structured interviews and review of medical records., Results: The cohort of 1,480 road trauma survivors included 280 pedestrians, 174 cyclists, 118 motorcyclists, 683 motor vehicle drivers, and 225 passengers. Median age was 40 (IQR = [27, 57]) years; 680 (46%) were female. Males and younger patients were significantly more likely to report better pre-injury physical health. Motorcyclists and cyclists tended to report better physical health and less severe somatic symptoms, whereas pedestrians and motor vehicle drivers reported better mental health. Injury severity and hospital admission rates were higher in pedestrians and motorcyclists and lower in motorists. Upper and lower extremity injuries were most common in pedestrians, cyclists and motorcyclists, whereas neck injuries were most common in motor vehicle drivers and passengers., Conclusions: In a large cohort of road trauma survivors, overall injury severity was low. Motorcyclists and pedestrians, but not cyclists, had more severe injuries than motorists. Extremity injuries were more common in vulnerable road users. Future research will investigate one-year recovery outcomes and identify risk factors for poor recovery., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Design: This was a prospective observational study., Background and Aims: The characteristics of cannabis-involved motor vehicle collisions are poorly understood. This study of injured drivers identifies demographic and collision characteristics associated with high tetrahydrocannabinol (THC) concentrations., Setting: The study was conducted in 15 Canadian trauma centres between January 2018 and December 2021., Cases: The cases (n = 6956) comprised injured drivers who required blood testing as part of routine trauma care., Measurements: We quantified whole blood THC and blood alcohol concentration (BAC) and recorded driver sex, age and postal code, time of crash, crash type and injury severity. We defined three driver groups: high THC (THC ≥ 5 ng/ml and BAC = 0), high alcohol (BAC ≥ 0.08% and THC = 0) and THC/BAC-negative (THC = 0 = BAC). We used logistic regression techniques to identify factors associated with group membership., Findings: Most injured drivers (70.2%) were THC/BAC-negative; 1274 (18.3%) had THC > 0, including 186 (2.7%) in the high THC group; 1161 (16.7%) had BAC > 0, including 606 (8.7%) in the high BAC group. Males and drivers aged less than 45 years had higher adjusted odds of being in the high THC group (versus the THC/BAC-negative group). Importantly, 4.6% of drivers aged less than 19 years had THC ≥ 5 ng/ml, and drivers aged less than 19 years had higher unadjusted odds of being in the high THC group than drivers aged 45-54 years. Males, drivers aged 19-44 years, rural drivers, seriously injured drivers and drivers injured in single-vehicle, night-time or weekend collisions had higher adjusted odds ratios (aORs) for being in the high alcohol group (versus THC/BAC-negative). Drivers aged less than 35 or more than 65 years and drivers involved in multi-vehicle, daytime or weekday collisions had higher adjusted odds for being in the high THC group (versus the high BAC group)., Conclusions: In Canada, risk factors for cannabis-related motor vehicle collisions appear to differ from those for alcohol-related motor vehicle collisions. The collision factors associated with alcohol (single-vehicle, night-time, weekend, rural, serious injury) are not associated with cannabis-related collisions. Demographic factors (young drivers, male drivers) are associated with both alcohol and cannabis-related collisions, but are more strongly associated with cannabis-related collisions., (© 2023 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Background: In 2011, policymakers in British Columbia introduced a fee-for-service payment to incentivize infectious diseases physicians to supervise outpatient parenteral antimicrobial therapy (OPAT). Whether this policy increased use of OPAT remains uncertain., Methods: We conducted a retrospective cohort study using population-based administrative data over a 14-year period (2004-2018). We focused on infections that required intravenous antimicrobials for ≥10 days (eg, osteomyelitis, joint infection, endocarditis) and used the monthly proportion of index hospitalizations with a length of stay shorter than the guideline-recommended "usual duration of intravenous antimicrobials" (LOS < UDIVA) as a surrogate for population-level OPAT use. We used interrupted time series analysis to determine whether policy introduction increased the proportion of hospitalizations with LOS < UDIVA., Results: We identified 18 513 eligible hospitalizations. In the pre-policy period, 82.3% of hospitalizations exhibited LOS < UDIVA. Introduction of the incentive was not associated with a change in the proportion of hospitalizations with LOS < UDIVA, suggesting that the policy intervention did not increase OPAT use (step change, -0.06%; 95% confidence interval [CI], -2.69% to 2.58%; P = .97 and slope change, -0.001% per month; 95% CI, -.056% to .055%; P = .98)., Conclusions: The introduction of a financial incentive for physicians did not appear to increase OPAT use. Policymakers should consider modifying the incentive design or addressing organizational barriers to expanded OPAT use., Competing Interests: Potential conflicts of interest. D. F. is the past president of the British Columbia Infectious Diseases Society (elected unpaid position) and reports advisory board participation and honoraria from Gilead Sciences, Inc, and AbbVie, Inc. J. M. S. reports support for attending meetings from the Government of Canada, the Government of Australia, the Province of Alberta, the Province of Ontario, and Cancer Care Ontario. J. R. B. reports competitive research grants from the Canadian Institutes of Health Research and Transport Canada and research contracts unrelated to this work from the British Columbia Ministry of Health and the Insurance Corporation of British Columbia. K. C. T. reports receipt of the Vancouver Coastal Health Mentored Clinician Scientist Award and participation on the Hypertension Canada Guideline Committee. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Physicians are often asked to counsel patients about driving safety after syncope, yet little empirical data guides such advice., Methods: We identified a population-based retrospective cohort of 9,507 individuals with a driver license who were discharged from any of six urban emergency departments (EDs) with a diagnosis of 'syncope and collapse'. We examined all police-reported crashes that involved a cohort member as a driver and occurred between 1 January 2010 and 31 December 2016. We categorized crash-involved drivers as 'responsible' or 'non-responsible' for their crash using detailed police-reported crash data and a validated responsibility scoring tool. We then used logistic regression to test the hypothesis that recent syncope was associated with driver responsibility for crash., Results: Over the 7-year study interval, cohort members were involved in 475 police-reported crashes: 210 drivers were deemed responsible and 133 drivers were deemed non-responsible for their crash; the 132 drivers deemed to have indeterminate responsibility were excluded from further analysis. An ED visit for syncope occurred in the three months leading up to crash in 11 crash-responsible drivers and in 5 crash-non-responsible drivers, suggesting that recent syncope was not associated with driver responsibility for crash (adjusted odds ratio, 1.31; 95%CI, 0.40-4.74; p = 0.67). However, all drivers with cardiac syncope were deemed responsible, precluding calculation of an odds ratio for this important subgroup., Conclusions: Recent syncope was not significantly associated with driver responsibility for traffic crash. Clinicians and policymakers should consider these results when making fitness-to-drive recommendations after syncope., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Staples et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Purpose: There is mounting evidence of racial and ethnic discrimination in the Canadian health care system. Patient level race and ethnicity data are required to identify potential disparities in clinical outcomes and access to health care. However, it is not known what patient race, ethnicity, and language data are collected by Canadian hospitals. This gap limits opportunities to identify and address inequalities in the health care system. The emergency department (ED) is a major point of contact for many patients accessing the health care system, and is therefore a reasonable place to conduct analysis of patient data collection. This study aims to quantify the proportion of Canadian EDs that collect patient race, ethnicity, and primary language data., Methods: We identified all Canadian EDs and distributed a survey to 616 EDs across the country., Results: We received responses representing 202 EDs (32.8%). One fifth (20.3%) of responding EDs reported that they collected race and ethnicity data and 38.1% collected primary language data. Reported uses for these data included quality improvement, research, and direct patient care., Conclusion: The majority of Canadian EDs do not collect patient race, ethnicity, and language data. This gap limits our ability to identify inequalities in health outcomes or access to health care. Lack of race, ethnicity, and language data also hinders our ability to develop and evaluate programs and interventions that aim to correct these inequalities., (© 2022. The Author(s), under exclusive licence to Canadian Association of Emergency Physicians (CAEP)/ Association Canadienne de Médecine d'Urgence (ACMU).)

Objectives: There is a growing demand for remote assessment options for measuring cognition after mild traumatic brain injury (mTBI). The current study evaluated the criterion validity of the Brief Test of Adult Cognition by Telephone (BTACT) in distinguishing between adults with mTBI and trauma controls (TC) who sustained injuries not involving the head or neck., Methods: The BTACT was administered to the mTBI (n = 46) and TC (n = 35) groups at 1-2 weeks post-injury. Participants also completed the Rivermead Post Concussion Symptoms Questionnaire., Results: The BTACT global composite score did not significantly differ between the groups (t(79) = -1.04, p = 0.30); the effect size was small (d = 0.23). In receiver operating characteristic curve analyses, the BTACT demonstrated poor accuracy in differentiating between the groups (AUC = 0.567, SE = 0.065, 95% CI [0.44, 0.69]). The BTACT's ability to discriminate between mTBI and TCs did not improve after excluding mTBI participants (n = 15) who denied ongoing cognitive symptoms (AUC = 0.567, SE = 0.072, 95% CI [0.43, 0.71])., Conclusions: The BTACT may lack sensitivity to subacute cognitive impairment attributable to mTBI (i.e., not explained by bodily pain, post-traumatic stress, and other nonspecific effects of injury).

Importance: Medical driving restrictions are burdensome, yet syncope recurrence while driving can cause a motor vehicle crash (MVC). Few empirical data inform current driving restrictions after syncope., Objective: To examine MVC risk among patients visiting the emergency department (ED) after first-episode syncope., Design, Setting, and Participants: A population-based, retrospective observational cohort study of MVC risk after first-episode syncope was performed in British Columbia, Canada. Patients visiting any of 6 urban EDs for syncope and collapse were age- and sex-matched to 4 control patients visiting the same ED in the same month for a condition other than syncope. Patients' ED medical records were linked to administrative health records, driving history, and detailed crash reports. Crash-free survival among individuals with syncope was then compared with that among matched control patients. Data analyses were performed from May 2020 to March 2022., Exposures: Initial ED visit for syncope., Main Outcomes and Measures: Involvement as a driver in an MVC in the year following the index ED visit. Crashes were identified using insurance claim data and police crash reports., Results: The study cohort included 43 589 patients (9223 patients with syncope and 34 366 controls; median [IQR] age, 54 [35-72] years; 22 360 [51.3%] women; 5033 [11.5%] rural residents). At baseline, crude MVC incidence rates among both the syncope and control groups were higher than among the general population (12.2, 13.2, and 8.2 crashes per 100 driver-years, respectively). In the year following index ED visit, 846 first crashes occurred in the syncope group and 3457 first crashes occurred in the control group, indicating no significant difference in subsequent MVC risk (9.2% vs 10.1%; adjusted hazard ratio [aHR], 0.93; 95% CI, 0.87-1.01; P = .07). Subsequent crash risk among patients with syncope was not significantly increased in the first 30 days after index ED visit (aHR, 1.07; 95% CI, 0.84-1.36; P = .56) or among subgroups at higher risk of adverse events after syncope (eg, age >65 years; cardiogenic syncope; Canadian Syncope Risk Score ≥1)., Conclusions and Relevance: The findings of this population-based retrospective cohort study suggest that patients visiting the ED with first-episode syncope exhibit a subsequent crash risk no different than the average ED patient. More stringent driving restrictions after syncope may not be warranted.

Cannabis is the second most commonly used impairing substance by drivers, after alcohol. As more countries legalize cannabis, there is concern that cannabis-impaired driving will increase. In many countries, police use roadside devices to test for oral fluid THC (the primary psychotropic component in cannabis) to identify drivers who used cannabis; including in countries with non-zero per se limits for THC in blood. This practice is questioned as previous research demonstrates a poor correlation between oral fluid and blood THC concentrations at the individual level. We conducted a meta-analysis to identify all research that compared oral fluid with blood THC levels. We obtained individual-level data from study authors and analyzed pooled individual-level data to calculate sensitivity and specificity of oral fluid THC (at various cut-off values) to detect blood THC above different concentration limits. Finally, we explored practical implications of using oral fluid THC in an enforcement context. Our review found THC concentrations measured in over 18,000 paired samples of oral fluid and blood. We found a good correlation between the presence of THC in oral fluid and presence of THC in blood (sensitivity = 71.2%, specificity = 97.7%). However oral fluid THC, at commonly used cut-off values, is less sensitive and less specific when used as a biomarker to detect people with blood THC concentrations above commonly used per se limits (such as 5 ng/mL). As such, there will be a large number of "false positive" tests if oral fluid THC testing were used as a biomarker for "illegal" THC concentrations in randomly selected drivers. We argue that the adverse implications of false positive oral fluid THC tests in this context outweigh the possible road safety benefits and we recommend against oral fluid THC screening in randomly selected drivers in countries with non-zero per se limits for blood THC. In contrast, oral fluid THC tests appear to be useful for investigating "high-risk" drivers who come to police attention because of evidence of impairment., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Introduction: Mental health problems frequently interfere with recovery from mild traumatic brain injury (mTBI) but are under-recognised and undertreated. Consistent implementation of clinical practice guidelines for proactive detection and treatment of mental health complications after mTBI will require evidence-based knowledge translation strategies. This study aims to determine if a guideline implementation tool can reduce the risk of mental health complications following mTBI. If effective, our guideline implementation tool could be readily scaled up and/or adapted to other healthcare settings., Methods and Analysis: We will conduct a triple-blind cluster randomised trial to evaluate a clinical practice guideline implementation tool designed to support proactive management of mental health complications after mTBI in primary care. We will recruit 535 adults (aged 18-69 years) with mTBI from six emergency departments and two urgent care centres in the Greater Vancouver Area, Canada. Upon enrolment at 2 weeks post-injury, they will complete mental health symptom screening tools and designate a general practitioner (GP) or primary care clinic where they plan to seek follow-up care. Primary care clinics will be randomised into one of two arms. In the guideline implementation tool arm, GPs will receive actionable mental health screening test results tailored to their patient and their patients will receive written education about mental health problems after mTBI and treatment options. In the usual care control arm, GPs and their patients will receive generic information about mTBI. Patient participants will complete outcome measures remotely at 2, 12 and 26 weeks post-injury. The primary outcome is rate of new or worsened mood, anxiety or trauma-related disorder on the Mini International Neuropsychiatric Interview at 26 weeks., Ethics and Dissemination: Study procedures were approved by the University of British Columbia's research ethics board (H20-00562). The primary report for the trial results will be published in a peer-reviewed journal. Our knowledge user team members (patients, GPs, policymakers) will co-create a plan for public dissemination., Trial Registration Number: ClinicalTrials.gov Registry (NCT04704037)., Competing Interests: Competing interests: NS has a private neuropsychological consulting practice and has received honoraria for providing continuing medical education. The other authors have no potential conflicts to declare., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Assess the impact of 24/7/365 emergency trauma radiology (ETR) coverage on Emergency Department (ED) patient flow in an urban, quaternary-care teaching hospital., Methods: Patient ED visit and imaging information were extracted from the hospital patient care information system for 2008 to 2018. An interrupted time-series approach with a comparison group was used to study the impact of 24/7/365 ETR on average monthly ED length of stay (ED-LOS) and Emergency Physician to disposition time (EP-DISP). Linear regression models were fit with abrupt and permanent interrupts for 24/7/365 ETR, a coefficient for comparison series and a SARIMA error term; subgroup analyses were performed by patient arrival time, imaging type and chief complaint., Results: During the study period, there were 949,029 ED visits and 739,796 diagnostic tests. Following implementation of 24/7/365 coverage, we found a significant decrease in EP-DISP time for patients requiring only radiographs (-29 min;95%CI:-52,-6) and a significant increase in EP-DISP time for major trauma patients (46 min;95%CI:13,79). No significant change in patient throughput was observed during evening hours for any patient subgroup. For overnight patients, there was a reduction in EP-DISP for patients with symptoms consistent with stroke (-78 min;95%CI:-131,-24) and for high acuity patients who required imaging (-33 min;95%CI:-57,-10). Changes in ED-LOS followed a similar pattern., Conclusions: At our institution, 24/7/365 in-house ETR staff radiology coverage was associated with improved ED flow for patients requiring only radiographs and for overnight stroke and high acuity patients. Major trauma patients spent more time in the ED, perhaps reflecting the required multidisciplinary management.

Background: The effect of cannabis legalization in Canada (in October 2018) on the prevalence of injured drivers testing positive for tetrahydrocannabinol (THC) is unclear., Methods: We studied drivers treated after a motor vehicle collision in four British Columbia trauma centers, with data from January 2013 through March 2020. We included moderately injured drivers (those whose condition warranted blood tests as part of clinical assessment) for whom excess blood remained after clinical testing was complete. Blood was analyzed at the provincial toxicology center. The primary outcomes were a THC level greater than 0, a THC level of at least 2 ng per milliliter (Canadian legal limit), and a THC level of at least 5 ng per milliliter. The secondary outcomes were a THC level of at least 2.5 ng per milliliter plus a blood alcohol level of at least 0.05%; a blood alcohol level greater than 0; and a blood alcohol level of at least 0.08%. We calculated the prevalence of all outcomes before and after legalization. We obtained adjusted prevalence ratios using log-binomial regression to model the association between substance prevalence and legalization after adjustment for relevant covariates., Results: During the study period, 4339 drivers (3550 before legalization and 789 after legalization) met the inclusion criteria. Before legalization, a THC level greater than 0 was detected in 9.2% of drivers, a THC level of at least 2 ng per milliliter in 3.8%, and a THC level of at least 5 ng per milliliter in 1.1%. After legalization, the values were 17.9%, 8.6%, and 3.5%, respectively. After legalization, there was an increased prevalence of drivers with a THC level greater than 0 (adjusted prevalence ratio, 1.33; 95% confidence interval [CI], 1.05 to 1.68), a THC level of at least 2 ng per milliliter (adjusted prevalence ratio, 2.29; 95% CI, 1.52 to 3.45), and a THC level of at least 5 ng per milliliter (adjusted prevalence ratio, 2.05; 95% CI, 1.00 to 4.18). The largest increases in a THC level of at least 2 ng per milliliter were among drivers 50 years of age or older (adjusted prevalence ratio, 5.18; 95% CI, 2.49 to 10.78) and among male drivers (adjusted prevalence ratio, 2.44; 95% CI, 1.60 to 3.74). There were no significant changes in the prevalence of drivers testing positive for alcohol., Conclusions: After cannabis legalization, the prevalence of moderately injured drivers with a THC level of at least 2 ng per milliliter in participating British Columbia trauma centers more than doubled. The increase was largest among older drivers and male drivers. (Funded by the Canadian Institutes of Health Research.)., (Copyright © 2022 Massachusetts Medical Society.)

Objective: To examine the degree to which neighborhood socioeconomic deprivation influences the risk of youth assault injury., Study Design: Population-based retrospective study of youth aged 10-24 years seeking emergency medical care between 2012 and 2019 at 14 hospitals in Vancouver, Canada. Neighborhood material and social deprivation were examined as independent predictors of assault injury, accounting for spatial autocorrelation and controlling for neighborhood drinking establishment density., Results: Our data included 4166 assault injuries among 3817 youth. Male sex, substance use, and mental health disorders were common among victims of assault. Relative to the least deprived quintile of neighborhoods, assault injury risk was 2-fold higher in the most materially deprived quintile of neighborhoods (incidence rate ratio per quintile increase, 1.17; 95% CI 1.06-1.30; P < .05), and risk in the most socially deprived quintile was more than 3-fold greater than in the least deprived quintile (incidence rate ratio per quintile increase, 1.35; 95% CI 1.21-1.50; P < .001). Assault risk was 147-fold greater between 2 and 3 AM on Saturday relative to the safest hours of the week., Conclusions: Neighborhood socioeconomic deprivation substantially increases the risk of youth assault injury. Youth violence prevention efforts should target socioeconomically deprived neighborhoods., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Chronic gray matter (GM) atrophy is a known consequence of moderate and severe traumatic brain injuries but has not been consistently shown in mild traumatic brain injury (mTBI). The aim of this study was to investigate the longitudinal effect of uncomplicated mTBI on the brain's GM and white matter (WM) from 6 weeks to 12 months after injury. Voxel-based-morphometry (VBM) was computed with the T1-weighted images of 48 uncomplicated mTBI patients and 37 orthopedic controls. Over the period from 6 weeks to 12 months, only patients who experienced uncomplicated mTBI, but not control participants, showed significant GM decrease predominantly in the right hemisphere along the GM-CSF border in lateral and medial portions of the sensorimotor cortex extending into the rolandic operculum, middle frontal gyrus, insula, and temporal pole. Additionally, only mTBI patients, but not controls, experienced significant WM decrease predominantly in the right hemisphere in the superior fasciculus longitudinalis, arcuate fasciculus, and cortical-pontine tracts as well as a significant WM increase in left arcuate fasciculus and left capsula extrema. We did not observe any significant change in the controls for the same time interval or any significant group differences in GM and WM probability at each of the two timepoints. This suggests that the changes along the brain tissue borders observed in the mTBI group represent a reorganization associated with subtle microscopical changes in intracortical myelin and not a direct degenerative process as a result of mTBI., (© 2021 The Authors. Brain and Behavior published by Wiley Periodicals LLC.)

Background: Opioids increase the risk of traffic crash by limiting coordination, slowing reflexes, impairing concentration and producing drowsiness. The epidemiology of prescription opioid use among drivers remains uncertain. We aimed to examine population-based trends and geographical variation in drivers' prescription opioid consumption., Methods: We linked 20 years of province-wide driving records to comprehensive population-based prescription data for all drivers in British Columbia (Canada). We calculated age- and sex-standardised rates of prescription opioid consumption. We assessed temporal trends using segmented linear regression and examined regional variation in prescription opioid use using maps and graphical techniques., Results: A total of 46 million opioid prescriptions were filled by 3.0 million licensed drivers between 1997 and 2016. In 2016 alone, 14.7% of all drivers filled at least one opioid prescription. Prescription opioid use increased from 238 morphine milligram equivalents per driver year (MMEs/DY) in 1997 to a peak of 834 MMEs/DY in 2011. Increases in MMEs/DY were greatest for higher potency and long-acting prescription opioids. The interquartile range of prescription opioid dispensation by geographical region increased from 97 (Q1=220, Q3=317) to 416 (Q1=591, Q3=1007) MMEs/DY over the study interval., Implications: Patterns of prescription opioid consumption among drivers demonstrate substantial temporal and geographical variation, suggesting they may be modified by clinical and policy interventions. Interventions to curtail use of potentially impairing prescription medications might prevent impaired driving., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Indicators can help decision-makers evaluate interventions in a complex, multi-sectoral injury system. We aimed to create indicators for road safety, seniors falls, and 'all-injuries' to inform and evaluate injury prevention initiatives in British Columbia, Canada. The indicator development process involved a five-stage mixed methodology approach, including an environmental scan of existing indicators, generating expert consensus, selection of decision-makers and conducting a survey, selection of final indicators, and specification of indicators. An Indicator Reference Group (IRG) reviewed the list of indicators retrieved in the environmental scan and selected candidate indicators through expert consensus based on importance, modifiability, acceptance, and practicality. Key decision-makers ( n = 561) were invited to rank each indicator in terms of importance and actionability (online survey). The IRG applied inclusion criteria and thresholds to survey responses from decision-makers, which resulted in the selection of 47 road safety, 18 seniors falls, and 33 all-injury indicators. After grouping "like" indicators, a final list of 23 road safety, 8 seniors falls, and 13 all-injury indicators were specified. By considering both decision-maker ranking and expert opinion, we anticipate improved injury system performance through advocacy, accountability, and evidence-based resource allocation in priority areas. Our indicators will inform a data management framework for whole-system reporting to drive policy and funding for provincial injury prevention improvement.

Background: In 2012, the Ministry of Health in British Columbia, Canada, introduced a $75 incentive payment that could be claimed by hospital physicians each time they produced a written post-discharge care plan for a complex patient at the time of hospital discharge., Objective: To examine whether physician financial payments incentivizing enhanced discharge planning reduce subsequent unplanned hospital readmissions., Design: Interrupted time series analysis of population-based hospitalization data., Participants: Individuals with one or more eligible hospitalizations occurring in British Columbia between 2007 and 2017., Main Measures: The proportion of index hospital discharges with subsequent unplanned hospital readmission within 30 days, as measured each month of the 11-year study interval. We used interrupted time series analysis to determine if readmission risk changed after introduction of the incentive payment policy., Key Results: A total of 40,588 unplanned hospital readmissions occurred among 409,289 eligible index hospitalizations (crude 30-day readmission risk, 9.92%). Policy introduction was not associated with a significant step change (0.393%; 95CI, - 0.190 to 0.975%; p = 0.182) or change-in-trend (p = 0.317) in monthly readmission risk. Policy introduction was associated with significantly fewer prescription fills for potentially inappropriate medications among older patients, but no improvement in prescription fills for beta-blockers after cardiovascular hospitalization and no change in 30-day mortality. Incentive payment uptake was incomplete, rising from 6.4 to 23.5% of eligible hospitalizations between the first and last year of the post-policy interval., Conclusion: The introduction of a physician incentive payment was not associated with meaningful changes in hospital readmission rate, perhaps in part because of incomplete uptake by physicians. Policymakers should consider these results when designing similar interventions elsewhere., Trial Registration: ClinicalTrials.gov ID, NCT03256734., (© 2021. Society of General Internal Medicine.)

Background: Electric scooters are personal mobility devices that have risen in popularity worldwide since 2017. Emerging reports suggest that both riders and other road users, such as pedestrians and cyclists, have been injured in electric scooter-associated incidents. We undertook a scoping review of the current literature to evaluate the injury patterns and circumstances of electric scooter-associated injuries., Methods: A scoping review of literature published from 2010 to 2020 was undertaken following accepted guidelines. Relevant articles were identified in Medline, Embase, SafetyLit and Transport Research International Documentation using terms related to electric scooters, injuries and incident circumstances. Supplemental searches were conducted to identify relevant grey literature (non-peer-reviewed reports)., Results: Twenty-eight peer-reviewed studies and nine grey literature records were included in the review. The current literature surrounding electric scooter-associated injuries mainly comprises retrospective case series reporting clinical variables. Factors relating to injury circumstances are inconsistently reported. Findings suggest that the head, upper extremities and lower extremities are particularly vulnerable in electric scooter falls or collisions, while injuries to the chest and abdomen are less common. Injury severity was inconsistently reported, but most reported injuries were minor. Low rates of helmet use among electric scooter users were noted in several studies., Conclusion: Electric scooters leave riders vulnerable to traumatic injuries of varying severity. Future work should prospectively collect standardised data that include information on the context of the injury event and key clinical variables. Research on interventions to prevent electric scooter injuries is also needed to address this growing area of concern., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Postgraduate medical trainees frequently work ≥ 24- hour shifts causing fatigue and adverse consequences such as motor vehicle incidents (MVIs). We aim to determine the incidence of MVIs during the commutes of trainees in British Columbia (BC) in the preceding year., Methods: We completed a retrospective, cross-sectional survey of trainees regarding work hours, shifts, and MVIs in the previous year. MVIs included falling asleep while driving, sudden braking or swerving to avoid a collision, unintentionally running a red light or stop sign, or collisions., Results: Of 273 respondents, over half (54.6%) reported ≥1 MVI, one in 14 were in a collision (7.0%), and two thirds (66.3%) reported that the safety of their commute had been impacted by fatigue in the past year. After adjustment for road exposure and shift-related factors, every ten km increase in commute length was associated with an increased risk of MVI (aOR=1.54;95%CI:1.15-2.12). Reported attentional failures, such as unintentionally running a red light and/or stop sign, increased for every ten hours on-call (aOR=1.44;95%CI:1.03-2.04) and for every additional past-midnight shift worked (aOR=1.13;95%CI:1.01-1.26)., Discussion: Trainees with longer and more frequent commutes had an increased risk of MVIs. Trainees who worked more hours on-call and more past-midnight shifts reported significantly more attentional failures while commuting. This study helps us understand factors affecting trainee commuter safety and supports calls for the provision of safe alternatives to commuting for postgraduate trainees., Competing Interests: Conflicts of Interest: The authors have no competing interests to declare., (© 2021 Cassidy, Croft, Erdelyi, Brubacher; licensee Synergies Partners.)

Objective: Social assistance helps fulfill the basic needs of low-income individuals. In British Columbia, social assistance is issued on the third or fourth Wednesday of every month. However, this sudden influx of resources may have negative health consequences. We investigated social assistance timing and emergency department (ED) visits related to trauma, mental health, and substance use., Methods: We conducted a retrospective multi-centre observational study using 12 years of regional ED data from Vancouver, British Columbia (2008-2020). Each cheque week (the week following social assistance disbursement) was matched to a single control week (2 weeks prior to cheque week). We compared the number of ED visits for trauma, mental health, and substance use during cheque weeks versus control weeks., Results: There were 253,360 visits during all weeks of interest. Cheque week was associated with significantly more ED visits for mental health and substance-related presentations (RR 1.07, 95% CI 1.03-1.11, p = 0.0006). These visits increased significantly for both males and females and for adults aged 17-64 years. Mental health and substance-related visits increased on the day of cheque disbursement (Wednesday) and the 4 days following (Thursday-Sunday). Trauma-related ED visits were elevated on the day of cheque disbursement, but not during other days of the week., Conclusions: Social assistance disbursement is followed by an increase in mental health and substance-related ED presentations and may be associated with an increase in trauma presentations on the day of cheque disbursement. These findings support calls for clinical and policy-level changes and support to reduce cheque day-associated harm., (© 2021. The Author(s), under exclusive licence to Canadian Association of Emergency Physicians (CAEP)/ Association Canadienne de Médecine d'Urgence (ACMU).)

Introduction: Previous studies on the effect of prescription medications on MVCs are sparse, not readily applicable to real-world driving and/or subject to strong selection bias. This study examines whether the presence of prescription medication in drivers' blood is associated with being responsible for MVC., Methods: This modified case-control study with responsibility analysis compares MVC responsibility rates among drivers with detectable levels of six classes of prescription medications (anticonvulsants, antidepressants, antihistamines, antipsychotics, benzodiazepines, opioids) versus those without. Data were collected between January 2010 and July 2016 from emergency departments in British Columbia, Canada. Collision responsibility was assessed using a validated and automated scoring of police collision reports. Multivariable logistic regression was used to determine OR of responsibility (analysed in 2018-2019)., Results: Unadjusted regression models show a significant association between anticonvulsants (OR 1.92; 95% CI 1.20 to 3.09; p=0.007), antipsychotics (OR 5.00; 95% CI 1.16 to 21.63; p=0.03) and benzodiazepines (OR 2.99; 95% CI 1.56 to 5.75; p=0.001) with collision responsibility. Fully adjusted models show a significant association between benzodiazepines with collision responsibility (aOR 2.29; 95% CI 1.16 to 4.53; p=0.02) after controlling for driver characteristics, blood alcohol and Δ-9-tetrahydrocannabinol concentrations, and the presence of other prescription medications. Antidepressants, antihistamines and opioids exhibited no significant associations., Conclusion: There is a moderate increase in the risk of a responsible collision among drivers with detectable levels of benzodiazepines in blood. Physicians and pharmacists should consider collision risk when prescribing or dispensing benzodiazepines. Public education about benzodiazepine use and driving and change to traffic policy and enforcement measures are warranted., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Many medications impair driving skills yet their influence on collision risk remains uncertain. We aimed to systematically investigate the risk of collision responsibility associated with common classes of prescription medications., Methods: In this population-based case-control study we analysed linked driving and health records in British Columbia, Canada from Jan 1, 1997, to Dec 31, 2016. The study cohort included all drivers involved in an incident collision (defined as first collision after 3 collision-free years) that resulted in a police report. We scored police collision reports and classified drivers as responsible for the collision (cases) or not responsible (controls); drivers with indeterminate scores were excluded. We used logistic regression to determine odds of collision responsibility in drivers with current prescriptions for medications of interest versus drivers without prescriptions. To explore whether risk of collision responsibility was related to medication effect or driver factors, we compared risk in current medication users versus past users. To study whether drivers developed tolerance to medication effects, we compared risk in new (first 30 days of a prescription) versus established users., Findings: During the study period, 4 906 925 drivers had their driving licence linked to health records; of these drivers, 747 662 unique drivers were involved in 837 919 incident collisions between Jan 1, 2000, and Dec 31, 2016. 382 685 drivers responsible for the collision (cases) and 332 259 drivers not responsible (controls) were included in the final analysis; 122 975 drivers with indeterminate responsibility were excluded. We found increased risk of collision responsibility in drivers prescribed sedating antipsychotics (adjusted odds ratio [aOR] 1·35 [98·75% CI 1·25-1·46]), long-acting benzodiazepines (aOR 1·30 [1·22-1·38]), short-acting benzodiazepines (aOR 1·25 [1·20-1·31]), and high-potency opioids (aOR 1·24 [1·17-1·30]). Among medications used for medical indications, the highest risk was seen in drivers prescribed neurological medications: cholinergic drugs (aOR 1·83 [1·39-2·40]), anticholinergic agents for Parkinson's disease (aOR 1·45 [1·08-1·96]), dopaminergic agents (aOR 1·20 [1·04-1·38]), and anticonvulsants (aOR 1·20 [1·14-1·26]). People currently taking benzodiazepines, non-sedating antidepressants, high-potency opioids, and anticonvulsants had increased risk compared with past users, and we did not find increased risk in new compared with established users of these drugs., Interpretation: Drivers prescribed benzodiazepines or high-potency opioids are at increased risk of being responsible for collisions and this risk does not decrease over time. Several other classes of medications are associated with increased risk, but this association might be independent of medication effect. These findings can guide medication warnings and prescription choices and inform public education campaigns targeting impaired driving., Funding: Canadian Institutes of Health Research., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.)