Structural basis for Cas9 off-target activity.

The target DNA specificity of the CRISPR-associated genome editor nuclease Cas9 is determined by complementarity to a 20-nucleotide segment in its guide RNA. However, Cas9 can bind and cleave partially complementary off-target sequences, which raises safety concerns for its use in clinical applications. Here, we report crystallographic structures of Cas9 bound to bona fide off-target substrates, revealing that off-target binding is enabled by a range of noncanonical base-pairing interactions within the guide:off-target heteroduplex. Off-target substrates containing single-nucleotide deletions relative to the guide RNA are accommodated by base skipping or multiple noncanonical base pairs rather than RNA bulge formation. Finally, PAM-distal mismatches result in duplex unpairing and induce a conformational change in the Cas9 REC lobe that perturbs its conformational activation. Together, these insights provide a structural rationale for the off-target activity of Cas9 and contribute to the improved rational design of guide RNAs and off-target prediction algorithms.

Conformational control of Cas9 by CRISPR hybrid RNA-DNA guides mitigates off-target activity in T cells.

The off-target activity of the CRISPR-associated nuclease Cas9 is a potential concern for therapeutic genome editing applications. Although high-fidelity Cas9 variants have been engineered, they exhibit varying efficiencies and have residual off-target effects, limiting their applicability. Here, we show that CRISPR hybrid RNA-DNA (chRDNA) guides provide an effective approach to increase Cas9 specificity while preserving on-target editing activity. Across multiple genomic targets in primary human T cells, we show that 2'-deoxynucleotide (dnt) positioning affects guide activity and specificity in a target-dependent manner and that this can be used to engineer chRDNA guides with substantially reduced off-target effects. Crystal structures of DNA-bound Cas9-chRDNA complexes reveal distorted guide-target duplex geometry and allosteric modulation of Cas9 conformation. These structural effects increase specificity by perturbing DNA hybridization and modulating Cas9 activation kinetics to disfavor binding and cleavage of off-target substrates. Overall, these results pave the way for utilizing customized chRDNAs in clinical applications.

Contact chemoreceptors mediate male-male repulsion and male-female attraction during Drosophila courtship.

The elaborate courtship ritual of Drosophila males is dictated by neural circuitry established by the transcription factor Fruitless and triggered by sex-specific sensory cues. Deciphering the role of different stimuli in driving courtship behavior has been limited by the inability to selectively target appropriate sensory classes. Here, we identify two ion channel genes belonging to the degenerin/epithelial sodium channel/pickpocket (ppk) family, ppk23 and ppk29, which are expressed in fruitless-positive neurons on the legs and are essential for courtship. Gene loss-of-function, cell-inactivation, and cell-activation experiments demonstrate that these genes and neurons are necessary and sufficient to inhibit courtship toward males and promote courtship toward females. Moreover, these cells respond to cuticular hydrocarbons, with different cells selectively responding to male or female pheromones. These studies identify a large population of pheromone-sensing neurons and demonstrate the essential role of contact chemosensation in the early courtship steps of mate selection and courtship initiation.

Prehospital Tranexamic Acid for Severe Trauma.

BACKGROUND: Whether prehospital administration of tranexamic acid increases the likelihood of survival with a favorable functional outcome among patients with major trauma and suspected trauma-induced coagulopathy who are being treated in advanced trauma systems is uncertain. METHODS: We randomly assigned adults with major trauma who were at risk for trauma-induced coagulopathy to receive tranexamic acid (administered intravenously as a bolus dose of 1 g before hospital admission, followed by a 1-g infusion over a period of 8 hours after arrival at the hospital) or matched placebo. The primary outcome was survival with a favorable functional outcome at 6 months after injury, as assessed with the use of the Glasgow Outcome Scale-Extended (GOS-E). Levels on the GOS-E range from 1 (death) to 8 ("upper good recovery" [no injury-related problems]). We defined survival with a favorable functional outcome as a GOS-E level of 5 ("lower moderate disability") or higher. Secondary outcomes included death from any cause within 28 days and within 6 months after injury. RESULTS: A total of 1310 patients were recruited by 15 emergency medical services in Australia, New Zealand, and Germany. Of these patients, 661 were assigned to receive tranexamic acid, and 646 were assigned to receive placebo; the trial-group assignment was unknown for 3 patients. Survival with a favorable functional outcome at 6 months occurred in 307 of 572 patients (53.7%) in the tranexamic acid group and in 299 of 559 (53.5%) in the placebo group (risk ratio, 1.00; 95% confidence interval [CI], 0.90 to 1.12; P = 0.95). At 28 days after injury, 113 of 653 patients (17.3%) in the tranexamic acid group and 139 of 637 (21.8%) in the placebo group had died (risk ratio, 0.79; 95% CI, 0.63 to 0.99). By 6 months, 123 of 648 patients (19.0%) in the tranexamic acid group and 144 of 629 (22.9%) in the placebo group had died (risk ratio, 0.83; 95% CI, 0.67 to 1.03). The number of serious adverse events, including vascular occlusive events, did not differ meaningfully between the groups. CONCLUSIONS: Among adults with major trauma and suspected trauma-induced coagulopathy who were being treated in advanced trauma systems, prehospital administration of tranexamic acid followed by an infusion over 8 hours did not result in a greater number of patients surviving with a favorable functional outcome at 6 months than placebo. (Funded by the Australian National Health and Medical Research Council and others; PATCH-Trauma ClinicalTrials.gov number, NCT02187120.).

Pharmacists in Trauma: a randomised controlled trial of emergency medicine pharmacists in trauma response teams.

BACKGROUND: Analgesia is an important component for patient well-being, but commonly delayed during trauma resuscitation. The Pharmacists in Trauma trial assessed the effects of integrating pharmacists into trauma response teams to improve analgesia delivery and medication management. METHODS: This unblinded randomised trial compared emergency medicine (EM) pharmacist involvement in trauma callouts versus standard care at an Australian level 1 trauma centre. Randomisation was performed via an online single sequence randomisation service. Eligible patients included those managed with a trauma callout during working hours of an EM pharmacist. Pharmacists were able to prescribe medications using a Partnered Pharmacist Medication Charting model. The primary outcome was the proportion of patients who had first dose analgesia within 30 min compared using the χ2 test. RESULTS: From 15 July 2021 until 31 January 2022, there were 119 patients randomised with 37 patients excluded as no analgesia was required. There were 82 patients included for analysis, 39 in the control arm and 43 in the intervention arm. The primary outcome was achieved in 25 (64.1%) patients in the control arm and 36 (83.7%) patients in the pharmacist arm (relative risk 1.31; 95% CI 1.0 to 1.71; p=0.042). Time to analgesia in the control arm was 28 (22-35) mins and 20 (15-26 mins) with pharmacist involvement; p=0.025. In the pharmacist arm, the initial dose of analgesia was prescribed by the pharmacist for 38 (88.4%) patients. There were 27 other medications prescribed by the pharmacist for the management of these patients. There were no differences in emergency and trauma centre or hospital length of stay. CONCLUSION: Addition of the EM pharmacist in trauma response teams improved time to analgesia. Involvement of an EM pharmacist in trauma reception and resuscitation may assist by optimising medication management, with members of the team more available to focus on other life-saving interventions. TRIAL REGISTRATION NUMBER: ACTRN12621000338864.

Optimizing Trauma Systems: A Geospatial Analysis of the Victorian State Trauma System.

OBJECTIVE: The aim of this study was to develop a data-driven approach to assessing the influence of trauma system parameters and optimizing the configuration of the Victorian State Trauma System (VSTS). SUMMARY BACKGROUND DATA: Regionalized trauma systems have been shown to reduce the risk of mortality and improve patient function and health-related quality of life. However, major trauma case numbers are rapidly increasing and there is a need to evolve the configuration of trauma systems. METHODS: A retrospective review of major trauma patients from 2016 to 2018 in Victoria, Australia. Drive times and flight times were calculated for transport to each of 138 trauma receiving hospitals. Changes to the configuration of the VSTS were modeled using a Mixed Integer Linear Programming algorithm across 156 simulations. RESULTS: There were 8327 patients included in the study, of which 58% were transported directly to a major trauma service (MTS). For adult patients, the proportion of patients transported directly to an MTS increased with higher transport time limit, greater probability of helicopter emergency medical service utilization, and lower hospital patient threshold numbers. The proportion of adult patients transported directly to an MTS varied from 66% to 90% across simulations. Across all simulations for pediatric patients, only 1 pediatric MTS was assigned. CONCLUSIONS: We have developed a robust and data-driven approach to optimizing trauma systems. Through the use of geospatial and mathematical models, we have modeled how potential future changes to trauma system characteristics may impact on the optimal configuration of the system, which will enable policy makers to make informed decisions about health service planning into the future.

Mental health and wellbeing of health and aged care workers in Australia, May 2021 - June 2022: a longitudinal cohort study.

OBJECTIVES: To assess the mental health and wellbeing of health and aged care workers in Australia during the second and third years of the coronavirus disease 2019 (COVID-19) pandemic, overall and by occupation group. DESIGN, SETTING, PARTICIPANTS: Longitudinal cohort study of health and aged care workers (ambulance, hospitals, primary care, residential aged care) in Victoria: May-July 2021 (survey 1), October-December 2021 (survey 2), and May-June 2022 (survey 3). MAIN OUTCOME MEASURES: Proportions of respondents (adjusted for age, gender, socio-economic status) reporting moderate to severe symptoms of depression (Patient Health Questionnaire-9, PHQ-9), anxiety (Generalized Anxiety Disorder scale, GAD-7), or post-traumatic stress (Impact of Event Scale-6, IES-6), burnout (abbreviated Maslach Burnout Inventory, aMBI), or high optimism (10-point visual analogue scale); mean scores (adjusted for age, gender, socio-economic status) for wellbeing (Personal Wellbeing Index-Adult, PWI-A) and resilience (Connor Davidson Resilience Scale 2, CD-RISC-2). RESULTS: A total of 1667 people responded to at least one survey (survey 1, 989; survey 2, 1153; survey 3, 993; response rate, 3.3%). Overall, 1211 survey responses were from women (72.6%); most respondents were hospital workers (1289, 77.3%) or ambulance staff (315, 18.9%). The adjusted proportions of respondents who reported moderate to severe symptoms of depression (survey 1, 16.4%; survey 2, 22.6%; survey 3, 19.2%), anxiety (survey 1, 8.8%; survey 2, 16.0%; survey 3, 11.0%), or post-traumatic stress (survey 1, 14.6%; survey 2, 35.1%; survey 3, 14.9%) were each largest for survey 2. The adjusted proportions of participants who reported moderate to severe symptoms of burnout were higher in surveys 2 and 3 than in survey 1, and the proportions who reported high optimism were smaller in surveys 2 and 3 than in survey 1. Adjusted mean scores for wellbeing and resilience were similar at surveys 2 and 3 and lower than at survey 1. The magnitude but not the patterns of change differed by occupation group. CONCLUSION: Burnout was more frequently reported and mean wellbeing and resilience scores were lower in mid-2022 than in mid-2021 for Victorian health and aged care workers who participated in our study. Evidence-based mental health and wellbeing programs for workers in health care organisations are needed. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12621000533897 (observational study; retrospective).

A qualitative descriptive study exploring clinicians' perspectives of the management of older trauma care in rural Australia.

BACKGROUND: For older trauma patients who sustain trauma in rural areas, the risk of adverse outcomes associated with advancing age, is compounded by the challenges encountered in rural healthcare such as geographic isolation, lack of resources, and accessibility. Little is known of the experience and challenges faced by rural clinicians who manage trauma in older adults. An understanding of stakeholders' views is paramount to the effective development and implementation of a trauma system inclusive of rural communities. The aim of this descriptive qualitative study was to explore the perspectives of clinicians who provide care to older trauma patients in rural settings. METHOD: We conducted semi-structured interviews of health professionals (medical doctors, nurses, paramedics, and allied health professionals) who provide care to older trauma patients in rural Queensland, Australia. A thematic analysis consisting of both inductive and deductive coding approaches, was used to identify and develop themes from interviews. RESULTS: Fifteen participants took part in the interviews. Three key themes were identified: enablers of trauma care, barriers, and changes to improve trauma care of older people. The resilience of rural residents, and breadth of experience of rural clinicians were strengths identified by participants. The perceived systemic lack of resources, both material and in the workforce, and fragmentation of the health system across the state were barriers to the provision of trauma care to older rural patients. Some changes proposed by participants included tailored education programs that would be taught in rural centres, a dedicated case coordinator for older trauma patients from rural areas, and a centralised system designed to streamline the management of older trauma patients coming from rural regions. CONCLUSIONS: Rural clinicians are important stakeholders who should be included in discussions on adapting trauma guidelines to the rural setting. In this study, participants formulated pertinent and concrete recommendations that should be weighed against the current evidence, and tested in rural centres.

Biases in the collection of blood alcohol data for adult major trauma patients in Victoria, Australia.

BACKGROUND: In-hospital alcohol testing provides an opportunity to implement prevention strategies for patients with high risk of experiencing repeated alcohol-related injuries. However, barriers to alcohol testing in emergency settings can prevent patients from being tested. In this study, we aimed to understand potential biases in current data on the completion of blood alcohol tests for major trauma patients at hospitals in Victoria, Australia. METHODS: Victorian State Trauma Registry data on all adult major trauma patients from 1 January 2018 to 31 December 2021 were used. Characteristics associated with having a blood alcohol test recorded in the registry were assessed using logistic regression models. RESULTS: This study included 14 221 major trauma patients, of which 4563 (32.1%) had a blood alcohol test recorded. Having a blood alcohol test completed was significantly associated with age, socioeconomic disadvantage level, preferred language, having pre-existing mental health or substance use conditions, smoking status, presenting during times associated with heavy community alcohol consumption, injury cause and intent, and Glasgow Coma Scale scores (p<0.05). Restricting analyses to patients from a trauma centre where blood alcohol testing was part of routine clinical care mitigated most biases. However, relative to patients injured while driving a motor vehicle/motorcycle, lower odds of testing were still observed for patients with injuries from flames/scalds/contact burns (adjusted OR (aOR)=0.33, 95% CI 0.18 to 0.61) and low falls (aOR=0.17, 95% CI 0.12 to 0.25). Higher odds of testing were associated with pre-existing mental health (aOR=1.39, 95% CI 1.02 to 1.89) or substance use conditions (aOR=2.33, 95% CI to 1.47-3.70), and living in a more disadvantaged area (most disadvantaged quintile relative to least disadvantaged quintile: aOR=2.30, 95% CI 1.52 to 3.48). CONCLUSION: Biases in the collection of blood alcohol data likely impact the surveillance of alcohol-related injuries. Routine alcohol testing after major trauma is needed to accurately inform epidemiology and the subsequent implementation of strategies for reducing alcohol-related injuries.

Enhanced study of facial soft tissues using a novel large scale histology technique.

The safety and effectiveness of facial cosmetic surgery procedures are dependent on detailed 3D understanding of the complex surgical anatomy of the face. Traditional, small sample size anatomical dissection studies have limitations in providing definitive clarification of the fascial layers of the face, and especially in their relationship with the facial nerve, and their reaction to surgical manipulation. The objective study of large tissue areas is required to effectively demonstrate the broader architecture. Conventional histology techniques were modified to handle extraordinarily large tissue samples to fulfill this requirement. Full-thickness soft tissue samples (skin to bone) of maximum length 18 cm, width 4 cm, and tissue thickness 1 cm, were harvested from 20 hemifaces of 15 fresh human cadavers (mean age at death = 81 years). After fixation, the samples were processed with an automated processor using paraffin wax for 156 h, sectioned at 30 µm, collected on gelatin-chromium-coated glass slides, stained with a Masson's Trichrome technique and photographed. Using this technique, excellent visualization was obtained of the fascial connective tissue and its relationship with the facial mimetic muscles, muscles of mastication and salivary glands in 73 large histological slides. The resulting slides improved the study of the platysma and superficial musculo-aponeurotic system (SMAS), the spaces and ligaments, the malar fat pad, and the facial nerve in relations to the deep fascia. Additionally, surgically induced changes in the soft-tissue organization were successfully visualized. This technique enables improved insight into the broad structural architecture and histomorphology of large-scale facial tissues.

Perceptions of an Interactive Trauma Recovery Information Booklet.

BACKGROUND: Previous research has shown that people with traumatic injuries have unmet information needs with respect to their injuries, management, and recovery. An interactive trauma recovery information booklet was developed and implemented to address these information needs at a major trauma center in Victoria, Australia. OBJECTIVE: The aim of this quality improvement project was to explore patient and clinician perceptions of a recovery information booklet introduced into a trauma ward. METHODS: Semistructured interviews with trauma patients, family members, and health professionals were undertaken and thematically analyzed using a framework approach. In total, 34 patients, 10 family members, and 26 health professionals were interviewed. RESULTS: Overall, the booklet was well accepted by most participants and was perceived to contain useful information. The design, content, pictures, and readability were all positively appraised. Many participants used the booklet to record personalized information and to ask health professionals questions about their injuries and management. CONCLUSION: Our findings highlight the usefulness and acceptability of a low-cost interactive booklet intervention to facilitate the provision of quality of information and patient-health professional interactions on a trauma ward.

Economic Evaluation of In-Hospital Clinical Practices in Acute Injury Care: A Systematic Review.

OBJECTIVES: Underuse of high-value clinical practices and overuse of low-value practices are major sources of inefficiencies in modern healthcare systems. To achieve value-based care, guidelines and recommendations should target both underuse and overuse and be supported by evidence from economic evaluations. We aimed to conduct a systematic review of the economic value of in-hospital clinical practices in acute injury care to advance knowledge on value-based care in this patient population. METHODS: Pairs of independent reviewers systematically searched MEDLINE, Embase, Web of Science, and Cochrane Central Register for full economic evaluations of in-hospital clinical practices in acute trauma care published from 2009 to 2019 (last updated on June 17, 2020). Results were converted into incremental net monetary benefit and were summarized with forest plots. The protocol was registered with PROSPERO (CRD42020164494). RESULTS: Of 33 910 unique citations, 75 studies met our inclusion criteria. We identified 62 cost-utility, 8 cost-effectiveness, and 5 cost-minimization studies. Values of incremental net monetary benefit ranged from international dollars -467 000 to international dollars 194 000. Of 114 clinical interventions evaluated (vs comparators), 56 were cost-effective. We identified 15 cost-effective interventions in emergency medicine, 6 in critical care medicine, and 35 in orthopedic medicine. A total of 58 studies were classified as high quality and 17 as moderate quality. From studies with a high level of evidence (randomized controlled trials), 4 interventions were clearly dominant and 8 were dominated. CONCLUSIONS: This research advances knowledge on value-based care for injury admissions. Results suggest that almost half of clinical interventions in acute injury care that have been studied may not be cost-effective.

Comparison of Out-of-Hospital Cardiac Arrests Occurring in Schools and Other Public Locations: A 12-Year Retrospective Study.

Objective: Out-of-hospital cardiac arrests (OHCA) in schools and universities are uncommon. However, these institutions must plan and prepare for such events to ensure the best outcomes. To evaluate their preparedness we assessed baseline characteristics, survival outcomes and 12-year trends for OHCA in schools/universities compared to other public locations.Methods: We conducted a retrospective analysis of OHCA in schools/universities and public locations between 2008 and 2019 using Victorian Ambulance Cardiac Arrest Registry data.Results: We included 9,037 EMS attended cases, 131 occurred in schools/universities and 8,906 in public locations. Compared to public locations, a significantly higher proportion of EMS treated cases in schools/universities received bystander cardiopulmonary resuscitation (CPR) (95.5% vs. 78.5%, p < 0.001), public access defibrillation (PAD) (26.1% vs. 9.9%, p < 0.001) and presented in shockable rhythms (69.4% vs. 50.9%, p < 0.001). Unadjusted survival to hospital discharge rates were also significantly higher in schools/universities (39.6% vs. 24.2%, p < 0.001). The long-term unadjusted trends for bystander CPR in schools/universities increased from 91.7% (2008-10) to 100% (2017-19) (p-trend = 0.025), for PAD from 4.2% (2008-10) to 47.5% (2017-19) (p-trend < 0.001) and for survival to hospital discharge from 16.7% (2008-10) to 57.5% (2017-19) (p-trend = 0.004). However, after adjustment for favorable cardiac arrest factors, such as younger age, bystander CPR and PAD, survival was similar between schools/universities and public locations.Conclusion: The majority of OHCA in schools and universities were witnessed and received bystander CPR, however less than half received PAD. Developing site-specific cardiac emergency response plans and providing age appropriate CPR training to primary, secondary and university students would help improve PAD rates.

Epidemiology and 6- and 12-Month Outcomes of Intimate Partner Violence and Other Violence-Related Traumatic Brain Injury in Major Trauma: A Population-Based Trauma Registry Study.

OBJECTIVE: To compare the epidemiology, in-hospital outcomes, and 6-month and 12-month patient-reported, outcomes of major trauma patients with intimate partner violence (IPV)-related traumatic brain injury (TBI) with other interpersonal violence (OV)-related TBI. SETTING: Victoria, Australia. PARTICIPANTS: Adult (≥18 years) major trauma cases with TBI (concussion, skull fracture, or intracranial injury), injured through IPV or OV, between July 2010 and June 2020, and included on the population-based Victorian State Trauma Registry. There were 133 adult major trauma cases due to IPV and 1796 due to OV. The prevalence of TBI was 39% (n = 52) in the IPV group and 56% (n = 1010) in the OV group. DESIGN: Registry-based cohort study. MAIN MEASURES: Trauma care indicators and 6- and 12-month patient-reported outcomes (self-reported disability, Glasgow Outcome Scale-Extended, EQ-5D-3L, and return to work). RESULTS: The annual incidence (95% CI) of major trauma involving TBI was 0.11 (0.08-0.14) per 100 000 population for IPV and 2.11 (1.98-2.24) per 100 000 for OV. A higher proportion of IPV-related cases were women (73% vs 5%), had sustained a severe TBI (Glasgow Coma Scale score 3-8; 27% vs 15%), were admitted to intensive care (56% vs 37%), and died in hospital (14% vs 5%). The median (interquartile range) time to definitive care (4.7 hours vs 3.3 hours) and head computed tomographic scan (5.0 hours vs 3.1 hours) was longer in the IPV group. Follow-up rates at 6 and 12 months were 71% and 69%, respectively. The 6- and 12-month outcomes were generally poorer in the IPV-related group. CONCLUSION: The incidence of IPV-related major trauma with TBI was low. However, the prevalence of severe TBI, the time to key aspects of clinical care, in-hospital mortality, and longer-term work-related disability were higher. However, power to detect differences was low due to the small number of IPV-related cases compared with the OV group.

Effect of Lower vs Higher Oxygen Saturation Targets on Survival to Hospital Discharge Among Patients Resuscitated After Out-of-Hospital Cardiac Arrest: The EXACT Randomized Clinical Trial.

Importance: The administration of a high fraction of oxygen following return of spontaneous circulation in out-of-hospital cardiac arrest may increase reperfusion brain injury. Objective: To determine whether targeting a lower oxygen saturation in the early phase of postresuscitation care for out-of-hospital cardiac arrest improves survival at hospital discharge. Design, Setting, and Participants: This multicenter, parallel-group, randomized clinical trial included unconscious adults with return of spontaneous circulation and a peripheral oxygen saturation (Spo2) of at least 95% while receiving 100% oxygen. The trial was conducted in 2 emergency medical services and 15 hospitals in Victoria and South Australia, Australia, between December 11, 2017, and August 11, 2020, with data collection from ambulance and hospital medical records (final follow-up date, August 25, 2021). The trial enrolled 428 of a planned 1416 patients. Interventions: Patients were randomized by paramedics to receive oxygen titration to achieve an oxygen saturation of either 90% to 94% (intervention; n = 216) or 98% to 100% (standard care; n = 212) until arrival in the intensive care unit. Main Outcomes and Measures: The primary outcome was survival to hospital discharge. There were 9 secondary outcomes collected, including hypoxic episodes (Spo2 <90%) and prespecified serious adverse events, which included hypoxia with rearrest. Results: The trial was stopped early due to the COVID-19 pandemic. Of the 428 patients who were randomized, 425 were included in the primary analysis (median age, 65.5 years; 100 [23.5%] women) and all completed the trial. Overall, 82 of 214 patients (38.3%) in the intervention group survived to hospital discharge compared with 101 of 211 (47.9%) in the standard care group (difference, -9.6% [95% CI, -18.9% to -0.2%]; unadjusted odds ratio, 0.68 [95% CI, 0.46-1.00]; P = .05). Of the 9 prespecified secondary outcomes collected during hospital stay, 8 showed no significant difference. A hypoxic episode prior to intensive care was observed in 31.3% (n = 67) of participants in the intervention group and 16.1% (n = 34) in the standard care group (difference, 15.2% [95% CI, 7.2%-23.1%]; OR, 2.37 [95% CI, 1.49-3.79]; P < .001). Conclusions and Relevance: Among patients achieving return of spontaneous circulation after out-of-hospital cardiac arrest, targeting an oxygen saturation of 90% to 94%, compared with 98% to 100%, until admission to the intensive care unit did not significantly improve survival to hospital discharge. Although the trial is limited by early termination due to the COVID-19 pandemic, the findings do not support use of an oxygen saturation target of 90% to 94% in the out-of-hospital setting after resuscitation from cardiac arrest. Trial Registration: ClinicalTrials.gov Identifier: NCT03138005.

Development and Validation of a Hospital Indicator of Activity-Based Costs for Injury Admissions.

OBJECTIVES: To develop a hospital indicator of resource use for injury admissions. METHODS: We focused on resource use for acute injury care and therefore adopted a hospital perspective. We included patients ≥16 years old with an Injury Severity Score >9 admitted to any of the 57 trauma centers of an inclusive Canadian trauma system from 2014 to 2018. We extracted data from the trauma registry and hospital financial reports and estimated resource use with activity-based costing. We developed risk-adjustment models by trauma center designation level (I/II and III/IV) for the whole sample, traumatic brain injuries, thoraco-abdominal injuries, orthopedic injuries, and patients ≥65 years old. Candidate variables were selected using bootstrap resampling. We performed benchmarking by comparing the adjusted mean cost in each center, obtained using shrinkage estimates, to the provincial mean. RESULTS: We included 38 713 patients. The models explained between 12% and 36% (optimism-corrected r2) of the variation in resource use. In the whole sample and in all subgroups, we identified centers with higher- or lower-than-expected resource use across level I/II and III/IV centers. CONCLUSIONS: We propose an algorithm to produce the indicator using data routinely collected in trauma registries to prompt targeted exploration of potential areas for improvement in resource use for injury admissions. The r2 of our models suggest that between 64% and 88% of the variation in resource use for injury care is dictated by factors other than patient baseline risk.

Cardiac arrests in general practice clinics or witnessed by emergency medical services: a 20-year retrospective study.

OBJECTIVE: To compare the frequency and outcomes of cardiac arrests in general practice clinics with those of paramedic-witnessed cardiac arrests. DESIGN, SETTING: Retrospective study; analysis of Victorian Ambulance Cardiac Arrest Registry data, 1 January 2000 - 30 December 2019. PARTICIPANTS: Patients with non-traumatic cardiac arrests whom emergency medical services staff attempted to resuscitate. MAIN OUTCOME MEASURES: Survival to hospital discharge. RESULTS: 6363 cases of cardiac arrest were identified: 216 in general practice clinics (3.4%) and 6147 witnessed by paramedics (96.6%). The proportion of patients presenting with initial shockable rhythms was larger in clinic (126 patients, 58.3%) than paramedic-witnessed cases (1929, 31.4%). The proportion of general practice clinic cases in which defibrillation was provided in the clinic increased from 2 of 37 in 2000-2003 (5%) to 19 of 57 patients in 2016-2019 (33%); survival increased from 7 of 37 (19%) to 23 of 57 patients (40%). For patients with initial shockable rhythms, 57 of 126 in clinic cases (45%) and 1221 of 1929 people in paramedic-witnessed cases (63.3%) survived to hospital discharge; of 47 general practice patients defibrillated by clinic staff, 27 survived (57%). For patients with initial shockable rhythms, the odds of survival were greater following paramedic-witnessed events (adjusted odds ratio [aOR], 3.39; 95% CI, 2.08-5.54) or general clinic arrests with defibrillation by clinic staff (aOR, 2.23; 95% CI, 1.03-4.83) than for general practice clinic arrests in which arriving paramedics provided defibrillation. CONCLUSION: Emergency medical services should be alerted as soon as possible after people experience heart attack warning symptoms. Automated external defibrillators should be standard equipment in general practice clinics, enabling prompt defibrillation, which may substantially reduce the risk of death for people in cardiac arrest.

Long-Term Outcomes after Severe Traumatic Brain Injury in Older Adults. A Registry-based Cohort Study.

Rationale: Older adults (≥65 yr old) account for an increasing proportion of patients with severe traumatic brain injury (TBI), yet clinical trials and outcome studies contain relatively few of these patients.Objectives: To determine functional status 6 months after severe TBI in older adults, changes in this status over 2 years, and outcome covariates.Methods: This was a registry-based cohort study of older adults who were admitted to hospitals in Victoria, Australia, between 2007 and 2016 with severe TBI. Functional status was assessed with Glasgow Outcome Scale Extended (GOSE) 6, 12, and 24 months after injury. Cohort subgroups were defined by admission to an ICU. Features associated with functional outcome were assessed from the ICU subgroup.Measurements and Main Results: The study included 540 older adults who had been hospitalized with severe TBI over the 10-year period; 428 (79%) patients died in hospital, and 456 (84%) died 6 months after injury. There were 277 patients who had not been admitted to an ICU; at 6 months, 268 (97%) had died, 8 (3%) were dependent (GOSE 2-4), and 1 (0.4%) was functionally independent (GOSE 5-8). There were 263 patients who had been admitted to an ICU; at 6 months, 188 (73%) had died, 39 (15%) were dependent, and 32 (12%) were functionally independent. These proportions did not change over longer follow-up. The only clinical features associated with a lower rate of functional independence were Injury Severity Score ≥25 (adjusted odds ratio, 0.24 [95% confidence interval, 0.09-0.67]; P = 0.007) and older age groups (P = 0.017).Conclusions: Severe TBI in older adults is a condition with very high mortality, and few recover to functional independence.

Low-value injury admissions in an integrated Canadian trauma system: A multicentre cohort study.

BACKGROUND: Injury represents 260 000 hospitalisations and $27 billion in healthcare costs each year in Canada. Evidence suggests that there is significant variation in the prevalence of hospital admissions among emergency department presentations between countries and providers, but we lack data specific to injury admissions. We aimed to estimate the prevalence of potentially low-value injury admissions following injury in a Canadian provincial trauma system, identify diagnostic groups contributing most to low-value admissions and assess inter-hospital variation. METHODS: We conducted a retrospective multicentre cohort study based on all injury admissions in the Québec trauma system (2013-2018). Using literature and expert consultation, we developed criteria to identify potentially low-value injury admissions. We used a multilevel logistic regression model to evaluate inter-hospital variation in the prevalence of low-value injury admissions with intraclass correlation coefficients (ICC). We stratified our analyses by age (1-15; 16-64; 65-74; 75+ years). RESULTS: The prevalence of low-value injury admissions was 16% (n = 19 163) among all patients, 26% (2136) in children, 11% (4695) in young adults and 19% (12 345) in older adults. Diagnostic groups contributing most to low-value admissions were mild traumatic brain injury in children (48% of low-value paediatric injury admissions; n = 922), superficial injuries (14%, n = 660) or minor spinal injuries (14%, n = 634) in adults aged 16-64 and superficial injuries in adults aged 65+ (22%, n = 2771). We observed strong inter-hospital variation in the prevalence of low-value injury admissions (ICC = 37%). CONCLUSION: One out of six hospital admissions following injury may be of low value. Children with mild traumatic brain injury and adults with superficial injuries could be good targets for future research efforts seeking to reduce healthcare services overuse. Inter-hospital variation indicates there may be an opportunity to reduce low-value injury admissions with appropriate interventions targeting modifications in care processes.