Introduction: Selecting appropriate patients for hospitalization following emergency department (ED) evaluation of syncope is critical for serious adverse event (SAE) identification. The primary objective of this study is to determine the association of hospitalization and SAE detection using propensity score (PS) matching. The secondary objective was to determine if SAE identification with hospitalization varied by the Canadian Syncope Risk Score (CSRS) risk-category. Methods: This was a secondary analysis of two large prospective cohort studies that enrolled adults (age ≥ 16 years) with syncope at 11 Canadian EDs. Patients with a serious condition identified during index ED evaluation were excluded. Outcome was a 30-day SAE identified either in-hospital for hospitalized patients or after ED disposition for discharged patients and included death, ventricular arrhythmia, non-lethal arrhythmia and non-arrhythmic SAE (myocardial infarction, structural heart disease, pulmonary embolism, hemorrhage). Patients were propensity matched using age, sex, blood pressure, prodrome, presumed ED diagnosis, ECG abnormalities, troponin, heart disease, hypertension, diabetes, arrival by ambulance and hospital site. Multivariable logistic regression assessed the interaction between CSRS and SAE detection and we report odds ratios (OR). Results: Of the 8183 patients enrolled, 743 (9.0%) patients were hospitalized and 658 (88.6%) were PS matched. The OR for SAE detection for hospitalized patients in comparison to those discharged from the ED was 5.0 (95%CI 3.3, 7.4), non-lethal arrhythmia 5.4 (95%CI 3.1, 9.6) and non-arrhythmic SAE 6.3 (95%CI 2.9, 13.5). Overall, the odds of any SAE identification, and specifically non-lethal arrhythmia and non-arrhythmia was significantly higher in-hospital among hospitalized patients than those discharged from the ED (p < 0.001). There were no significant differences in 30-day mortality (p = 1.00) or ventricular arrhythmia detection (p = 0.21). The interaction between ED disposition and CSRS was significant (p = 0.04) and the probability of 30-day SAEs while in-hospital was greater for medium and high risk CSRS patients. Conclusion: In this multicenter prospective cohort, 30-day SAE detection was greater for hospitalized compared with discharged patients. CSRS low-risk patients are least likely to have SAEs identified in-hospital; out-patient monitoring for moderate risk patients requires further study.

Introduction: Wide variability exists in emergency department (ED) syncope management. The Canadian Syncope Risk Score (CSRS) was derived and validated to predict the probability of 30-day serious outcomes after ED disposition. The objective was to identify barriers and facilitators among physicians for CSRS use to stratify risk and guide disposition decisions Methods: We conducted semi-structured interviews with physicians involved in ED syncope care at 8 Canadian sites. We used purposive sampling, contacting ED physicians, cardiologists, internists, and hospitalists until theme saturation was reached. Interview questions were designed to understand whether the CSRS recommendations are consistent with current practice, barriers and facilitators for application into practice, and intention for future CSRS use. Interviews were conducted via telephone or videoconference. Two independent raters coded interviews using an inductive approach to identify themes, with discrepancies resolved through consensus. Our methods were consistent with the Knowledge to Action Framework, which highlights the need to assess barriers and facilitators for knowledge use and for adapting new interventions into local contexts. Results: We interviewed 14 ED physicians, 7 cardiologists, and 10 hospitalists/internists across 8 sites. All physicians reported the use of electrocardiograms for patients with syncope, a key component in the CSRS criteria. Almost all physicians reported that the low risk recommendation (discharge without specific follow-up) was consistent with current practice, while less consistency was seen for moderate (15 days outpatient monitoring) and high risk recommendations (outpatient monitoring and/or admission). Key barriers to following the CSRS included a lack of access to outpatient monitoring and uncertainty over timely follow-up care. Other barriers included patient/family concerns, social factors, and necessary bloodwork. Facilitators included assisting with patient education, reassurance of their clinical gestalt, and optimal patient factors (e.g. reliability to return, support at home, few comorbidities). Conclusion: Physicians are receptive to using the CSRS tool for risk stratification and decision support. Implementation should address identified barriers, and adaptation to local settings may involve modifying the recommended clinical actions based on local resources and feasibility.

Introduction: Emergency department (ED) syncope management is extremely variable. We developed practice recommendations based on the validated Canadian Syncope Risk Score (CSRS) and outpatient cardiac monitoring strategy with physician input. Methods: We used a 2-step approach. Step-1: We pooled data from the derivation and validation prospective cohort studies (with adequate sample size) conducted at 11 Canadian sites (Sep 2010 to Apr 2018). Adults with syncope were enrolled excluding those with serious outcome identified during index ED evaluation. 30-day adjudicated serious outcomes were arrhythmic (arrhythmias, unknown cause of death) and non-arrhythmic (MI, structural heart disease, pulmonary embolism, hemorrhage)]. We compared the serious outcome proportion among risk categories using Cochran-Armitage test. Step-2: We conducted semi-structured interviews using observed risk to develop and refine the recommendations. We used purposive sampling of physicians involved in syncope care at 8 sites from Jun-Dec 2019 until theme saturation was reached. Two independent raters coded interviews using an inductive approach to identify themes; discrepancies were resolved by consensus. Results: Of the 8176 patients (mean age 54, 55% female), 293 (3.6%; 95%CI 3.2-4.0%) experienced 30-day serious outcomes; 0.4% deaths, 2.5% arrhythmic, 1.1% non-arrhythmic outcomes. The serious outcome proportion significantly increased from low to high-risk categories (p < 0.001; overall 0.6% to 27.7%; arrhythmic 0.2% to 17.3%; non-arrhythmic 0.4% to 5.9% respectively). C-statistic was 0.88 (95%CI0.86–0.90). Non-arrhythmia risk per day for the first 2 days was 0.5% for medium-risk, 2% for high-risk and very low thereafter. We recruited 31 physicians (14 ED, 7 cardiologists, 10 hospitalists/internists). 80% of physicians agreed that low risk patients can be discharged without specific follow-up with inconsistencies around length of ED observation. For cardiac monitoring of medium and high-risk, 64% indicated that they don't have access; 56% currently admit high-risk patients and an additional 20% agreed to this recommendation. A deeper exploration led to following refinement: discharge without specific follow-up for low-risk, a shared decision approach for medium-risk and short course of hospitalization for high-risk patients. Conclusion: The recommendations were developed (with online calculator) based on in-depth feedback from key stakeholders to improve uptake during implementation.

Serotonin is well known to affect the multifaceted construct of impulsivity. Lowering brain serotonin levels is shown to increase impulsive choice in delay-discounting tasks (1) but improves response inhibition in stop-signal paradigms. (2) Administration of the antidepressant citalopram in healthy people increases tendency to perform go choices in a Go/No-Go task independent of outcome valence (3). It is rather unclear thought how serotonergic neurotransmission affects several aspects of cognition. We administered a single dose of 20 mg escitalopram, a selective serotonin reuptake inhibitor, to 66 healthy participants, aged 18–45 years old, in a double-blind, randomized, placebo-controlled, parallel-groups study. Acute escitalopram administration had a beneficial effect on inhibitory control with reduced stop-signal reaction time observed in the treatment group. Participants made significantly more errors in a probabilistic learning task and had lower accuracy during the discrimination stage in an instrumental learning task thus indicating a learning impairment. More errors in the CANTAB intra-extra dimensional set shift task were also observed in the escitalopram-treated group. Our findings following acute administration of a clinically relevant dose of escitalopram show a dissociate role for serotonin in modulating cognition mediated by a potentially differential modulation of fronto-striatal loops.

The role of silicon (Si) in alleviating the effects of biotic and abiotic stresses, including defence against insect herbivores, in plants is widely reported. Si defence against insect herbivores is overwhelmingly studied in grasses (especially the cereals), many of which are hyper-accumulators of Si. Despite being neglected, legumes such as soybean (Glycine max) have the capacity to control Si accumulation and benefit from increased Si supply. We tested how Si supplementation via potassium, sodium or calcium silicate affected a soybean pest, the native budworm Helicoverpa punctigera Wallengren (Lepidoptera: Noctuidae). Herbivory reduced leaf biomass similarly in Si-supplemented (+Si) and non-supplemented (–Si) plants (c. 29 and 23%, respectively) relative to herbivore-free plants. Both Si supplementation and herbivory increased leaf Si concentrations. In relative terms, herbivores induced Si uptake by c. 19% in both +Si and –Si plants. All Si treatments reduced H. punctigera relative growth rates (RGR) to a similar extent for potassium (−41%), sodium (−49%) and calcium (−48%) silicate. Moreover, there was a strong negative correlation between Si accumulation in leaves and herbivore RGR. To our knowledge, this is only the second report of Si-based herbivore defence in soybean; the rapid increase in leaf Si following herbivory being indicative of an induced defence. Taken together with the other benefits of Si supplementation of legumes, Si could prove an effective herbivore defence in legumes as well as grasses.

Introduction: Concussions are one of the most common sports-related injuries presenting to emergency departments (EDs), and are particularly frequent among players of contact sports such as ice hockey (hockey). Studies of youth hockey players report increased concussion incidence when participating in levels of hockey that allow body-checking. In 2016, an Edmonton minor hockey organization implemented a policy to remove body checking from play for non-elite levels of Bantam (13-14 years) and Midget (15-17 years). This study aimed to evaluate the effect of this policy on occurrence of concussions in male minor hockey players. Methods: Alberta Health Services Sport and Recreation codes (SR = 54) were used to identify Bantam and Midget hockey players presenting to Edmonton Zone emergency departments (ED) during the 2013/2014 to 2016/2017 hockey seasons from the National Ambulatory Care Record System. Injured hockey players with a concussion were identified using International Classification of Diseases 10-CA diagnosis code S06.0. Odds ratios (OR) of concussions among total hockey injuries before (2013-2016) and after (2016-2017) the policy are reported with 95% confidence intervals (CIs). Differences were assessed using Pearson's χ2 test. Results: During the study period, 1978 minor hockey players presented to an Edmonton Zone ED with a hockey-related injury, including 272 players with a concussion (14%). Most of the injuries occurred to Midget players (n = 1274). The proportions of concussion were similar before and after the policy change for players of all ages (OR = 0.78; 95% CI: 0.37 to 0.92) and for injured Bantam players (OR = 0.97; 95% CI: 0.59 to 1.55); however, there was a significant reduction in concussions as a proportion of all injuries for Midget players before and after the policy change (OR = 0.61; 95% CI: 0.36 to 1.00). Conclusion: In the initial year of implementation, the policy to limit body-checking to elite levels of play had mixed results. While the policy change did not result in a significant reduction in concussions overall, or for Bantam players, Midget players did experience a significant reduction in concussions after the policy change. The reasons behind these age-related differences require further investigation. Moreover, further evaluation of the policy using additional years of post-policy data, as well as hockey registration numbers, is needed to evaluate the sustainability of its effect.

Introduction: Variation in image ordering exists across Alberta emergency departments (EDs). Evidence-based, pocket-sized knowledge dissemination tools were developed for two conditions (acute asthma [AA] and benign headache [BHA]) for which imaging (chest x-ray [CXR] and computed tomography [CT], respectively) has limited utility. This study explored tool acceptability among ED patients and emergency physicians (EPs). Methods: Tool feedback was provided by EPs, via online survey, and adult patients with AA and BHA via in-person survey. EPs qualitative interviews further explored communication tools. Preliminary descriptive analyses of survey responses and content analysis of interview data were conducted. Results: Overall, 55 EPs (55/192; 29%) and 38 consecutive patients participated in the AA study; 73 EPs (73/192; 38%) and 160 patients participated in the BHA study. In both studies, approximately 50% of EPs felt comfortable using the tool; however, they suggested including radiation risk details and imaging indications and removing references to imaging variation and health system cost. In the BHA study, EPs opposed the four Choosing Wisely® campaign questions fearing they would increase imaging expectations. In both conditions, most patients ( >90%) understood the content and 68% felt the information applied to them. Less than half (AA:45%; BHA: 38%) agreed that they now knew more about when a patient should have imaging workup done. Following tool review, 71% of AA and 50% of BHA patients stated they would discuss their imaging needs with their ED care provider today or during a future presentation. Both patient groups suggested including: additional imaging details (i.e., indications, risk, clinical utility), removing imaging overuse references, and including instructions that encourage patients to ask their EP questions. EP interviews (n = 12) identified preferences for personalized and interactive tools. Tensions were perceived around ED time pressure as well as remuneration schemes that fail to prioritize patient conversation. Tool centralization, easy access, and connection with outpatient support were also key themes. Conclusion: Both patients and EPs provided valuable information on how to improve ED knowledge dissemination tools, using two chronic conditions to demonstrate how these changes would improve tool utility. Implementing these recommendations, and considering preferences of EPs and patients, may improve future tool uptake and impact.

Introduction: Variation in medication management and image ordering for HA presentation to emergency departments (ED) has been documented. This study examined benign HA (i.e., migraine, cluster, tension) management in order to identify the consistency and appropriateness of HA management in EDs in Alberta. Methods: Patients were identified by primary discharge diagnosis in the National Ambulatory Care Reporting System using ICD-10-CA codes for benign HA (G43, G44, R51). Patients presenting to study sites from January 1, 2017 to September 30, 2017 were eligible for inclusion, provided they were adults (≥18 years), were not transferred from another institution or directly admitted to a service, and had an active HA at presentation. One hundred eligible patients were randomly selected for chart review. Data were extracted on standardized forms. Preliminary data on 50 patients (n = 150) from three Edmonton study sites is presented. Results: Most patients arrived to the ED via personal transportation (93%) and were assigned a Canadian Triage and Acuity Scale (CTAS) score of 3 (71%). The majority of patients were female (75%); mean age was 45 years (standard deviation: 18). Triage pain score was not documented for 21%. When documented, pain scores were most frequently between 4 and 7 (49%). Nearly 10% of patients left without being seen. For those who were assessed, physicians most frequently used ketorolac and metoclopramide as first or second line treatments or as a combination treatment. Consults were infrequent (14%). Nearly half of the patients (47%). had computed tomography (CT) in the ED. Pain re-assessment was completed for 69% of patients. Most patients were discharged from the ED (88%) and given some form of discharge instruction (78%). The most common instructions were to return to ED as needed (45%) and follow-up with their primary care physician (28%). Across all patients, 13% returned to the ED with headache within 30 days. Conclusion: Physicians treat patients with benign headaches appropriately and hospitalization is infrequent; however, one in eight patients relapse. Missing pain scale documentation reveals a potential problem for ED clinicians in assessing management effectiveness and ensuring patients leave the ED following pain relief. Half of the patients received a CT scan, highlighting the urgent need for an intervention to address CT overuse for patients with benign HA within this geographic region.

Introduction: Asthma and/or chronic obstructive pulmonary disease (COPD) exacerbations often result in emergency department (ED) visits. This study examined the health-related personnel providing regular care to patients with asthma and/or COPD, as well as, explored the coordination of care between the ED and outpatient settings. Methods: Descriptive cross-sectional examination of patients presenting with asthma and/or COPD exacerbations to two EDs in Edmonton between August and December 2017. Using patient interview methods information on demographics, established health care connections and health system use was collected; information on consultations, disposition and referrals was collected through chart review methods. Results: A total of 50 patients were recruited (14 patients with asthma and 36 patients with COPD). Most of the patients with asthma were female (64%) and their median age was 36 years (interquartile range [IQR]: 29, 46); sex was evenly distributed among the patients with COPD and their median age was 68 years (IQR: 61, 78). The majority reported having a family doctor (86% of the patients with asthma and 94% of the patients with COPD). On the day of admission to the ED, 29% of the patients with asthma visited their family doctor while 42% of the patients with COPD visited their Respirologist; these doctors referred >70% of the patients to the ED. While in the ED, consultations were requested in 21% of the patients with asthma (all to Pulmonary) and in 78% of the patients with COPD (evenly divided between Medicine and Pulmonary). Transition coordinators and social workers were involved in the ED care of <15% of the patients with COPD. Most patients with asthma were discharged home (86%) and 64% of the patients with COPD were hospitalized. After discharge, 14% of the patients with asthma and 50% of the patients with COPD were referred to specialized care. Conclusion: While the study patients with asthma and COPD had different health professionals providing regular care to their respiratory conditions, they both sought care before presenting to the ED. More health professionals were involved in the ED care of patients with COPD than of those with asthma. This study provided important information to support further research projects exploring ways to effectively and efficiently improve the delivery, comprehensiveness and utilization of health care services.

Introduction: Emergency Department (ED) Transition Coordinators (TC) have been introduced to many EDs. In Alberta, the EDTC role was designed to evaluate the home needs of senior patients (75 years of age) to enable safe return home after an ED visit, thereby mitigating admissions and return ED visits. The effectiveness of this role at achieving its objectives has received limited evaluation. Methods: TCs assess all ED patients 75 years old, and physicians request TC assessment for patients <75 years. The TC assessment includes completing a Transitional Assessment Referral (TAR) form that collects information on comorbidities, living arrangements, connections to community and homecare services, independence in activities of daily living (ADLs), and referrals, and disposition. Trained research staff extracted data from consecutive TARs for patients presenting during April 2017 into a REDCap database. The proportions of patients seen by TCs who were admitted, had an unplanned return to the ED within the study period, or received a new homecare referral were assessed. Categorical variables are reported as proportions; continuous variables are reported as mean and standard deviation (SD) or median and interquartile range (IQR), as appropriate. Results: In April 2017, there were 9849 visits to the ED; of these, TCs assessed 478 patients during 500 visits. The mean age was 82 (SD=11.2) and 41% were male; 22 patients presented twice during April 2017. Patients had a median of 2 (IQR: 1, 5) co-morbidities and 40 (8%) patients reported falls in the past 90 days (median=1; IQR: 1, 2). Overall, 144 (29%) patients lived in a care facility, while 204 (41%) lived at home; residence was unclear or not documented for 152 (30%). Patients reported being independent in a median of 9/14 (IQR: 3, 13) ADLs. An existing homecare connection or receipt of homecare services was documented for 185 patients (37%). Finally, 59 (12%) visits included a new or updated homecare referral, while 200 (33%) ED visits ended in admission. Conclusion: Elderly patients seen in the ED assessed by EDTCs are complex, and despite being well connected, they frequently need hospitalization. In a small proportion of cases, additional or new home care resources are required prior to ED discharge; however, few patients returned to the same ED during the one month study period. Given the high proportion of patients assessed, further evaluation of outcomes is warranted.

Introduction: Increase in functional decline of older adults after discharge from the emergency department (ED) has been reported; however, evaluations of interventions to mitigate this problem are infrequent. Data collected in the ED on older adults may document functional status, yet their utility for research is unknown. This study aimed to assess the usability of data collected by ED Transition Coordinators (EDTC) during routine assessments for functional decline research. Methods: EDTCs assess all patients 75 years old presenting to the ED and complete a standardized Transitional Assessment Referral (TAR) form that documents patients independence and daily functioning. To measure the utility of these forms for research purposes, trained research staff evaluated the TARs completed in April 2017 by TCs in the University of Alberta Hospital ED by extracting data from the TARs into a purpose-built REDCap database. Researchers selected and assessed for completeness and clarity the following variables unique to the TARs: facility vs. non-facility living, goals of care and personal directive, fall history, falls in the past 90 days, independence in 14 activities of daily living (ADLs)/instrumental activities of daily living (IADLS), community services in place, and homecare referrals for discharged patients. The proportion of TARs with data for each variable and the proportion of forms with unambiguous responses in each section are reported. Results: Overall, 500 forms were analysed; patients were 41% male with a mean age of 82 (SD=11.2). Homecare referrals, facility vs. non-facility living, and independence with 14 ADLs/IADLs were the most frequently documented variables (81%, 78%, and 79%, respectively); however for ADLs/IADLs, 59% of the 79% had one or more missing components. While fall history was reported in 301 forms (60%), only 107/301 (36%) reported the number of falls in the last 90 days. The referral to homecare variable was complete in 217/268 (81%) forms; however, 99% of files were missing data about goals of care, personal directives, and receipt of community services. Conclusion: Although some information on elderly patients is consistently reported, many of the social service/human factors associated with functional decline are not recorded. While data on the TARs may be useful for studying functional decline in the ED, exploring the barriers to form completion may improve adherence thereby increasing their research utility.

Introduction: Unnecessary care is an increasingly commonly used term in medicine. Previous survey research suggests that definitions of unnecessary care vary within and among professional and patient groups. This research explores how emergency physicians and administrators understand the term unnecessary care. Methods: Site chiefs and emergency physicians in an Alberta region were recruited through email and online surveys respectively for a qualitative study. One hour one-on-one in-depth interviews explored understandings of unnecessary care within the emergency department (ED) context. Interview transcripts underwent thematic analysis. Results: Five physicians and seven site chiefs completed interviews. Two key themes emerged. First, interviewees conceptualized unnecessary care as inappropriate or non-urgent presentations. This patient-centric view raised non-urgent ED presentations as a health system problem with complex components, including: lack of public knowledge of healthcare resources, shrinking comfort and scope of community providers and patient willingness to utilize other resources. Despite concerns over non-urgent visits, interviewees expressed that these patients still need to be seen, assessed and managed. The second conceptualization focused on over-investigation (and to lesser extent, treatment). This physician-centric conceptualization identified issues around: variation in physician risk tolerance, established decision rules with the allowable miss rates, patient expectation for testing or physician feeling that the patient was owed something or that patient would not accept their diagnosis/treatment without testing. Additionally, interviewees described patient characteristics that may initiate more aggressive investigation (e.g., patient reliability, follow-up care access, etc.). An overarching concern about the connection between unnecessary care and wasted resources was identified. Additionally, interviewees emphasized that patient conversations are outside the scope of unnecessary care despite their possible implications for limited time resources. Conclusion: A range of concepts surrounding unnecessary care in the ED were identified. Further exploring nuances of these conceptualizations may inform and improve the effectiveness of campaigns seeking to improve efficiency in practice and reduce inappropriate care. Additionally, this work provides an impetus for developing clearer concepts of care within the ED.

Introduction: Introduction: Transitions in care (TiC) interventions have been proposed to improve the management and outcomes of patients in emergency departments (ED). The objective of this review was to examine the effectiveness of ED-based TiC interventions to improve outcomes for adult patients presenting to an ED with acute atrial fibrillation or flutter (AFF). Methods: Methods: A comprehensive search of eight electronic databases and various grey literature sources was conducted. Comparative studies assessing the effectiveness of interventions to improve TiC for patients presenting to the ED with acute AFF were eligible. Two independent reviewers completed study selection, quality assessment, and data extraction. When applicable, relative risks (RR) with 95% confidence intervals (CIs) were calculated using a random effects model and heterogeneity was reported among studies using I-square (I2) statistics. Results: Results: From 744 citations, seven studies were included, consisting of three randomized controlled trials (RCT), three before-after (B/A) studies, and one cohort study. Study quality ranged from unclear to low for the RCTs according to the risk of bias tool, moderate in the BA trials according to the BA quality assessment tool, and high quality of the cohort study according to the Newcastle Ottawa scale. The majority of interventions were set within-ED (n=5), including three clinical pathways/management guidelines and two within-ED observation units. Post-ED interventions (n=2) included patient education and general practitioner referral. Four studies reported a decreased overall hospital length of stay (LoS) for AFF patients undergoing TiC interventions compared to control, ranging from 26.4 to 53 hours; however, incomplete and non-standardized outcome reporting precluded meta-analysis. An increase in conversion to normal sinus rhythm among TiC intervention patients was noted, which may be related to increased utilization of electrical cardioversion among the RCTs (RR=2.16; 95% CI: 1.42, 3.30; I2=%), B/A studies (RR=2.69, 95% CI: 2.17, 3.33), and cohort study (RR=1.39; 95% CI: 1.24, 1.56). Conclusion: Conclusions: Within-ED TiC interventions may reduce hospital LoS and increase use of electrical cardioversion. However, no clear recommendations to implement such interventions in EDs can be generated from this systematic review and more efforts are required to improve TiC for patients with AFF.

Introduction: Despite the provision of evidence-based care, approximately 15% of patients discharged from the emergency department (ED) after being treated for asthma exacerbations will relapse within two weeks. This study summarizes the evidence regarding relapses and factors associated with increased relapse in patients discharged from EDs after being treated for asthma exacerbations. Methods: Comprehensive literature searches were conducted in seven electronic databases; manual and grey literature searches were performed. Studies tracking outcomes for adults after ED management and discharge were included. Methodological quality was assessed using the Newcastle-Ottawa Scale (NOS) and the Risk of Bias (RoB) tools. Studies were summarized using medians and interquartile ranges (IQR) or mean and standard deviation (±SD), as appropriate. Results: From 793 potentially relevant citations, 178 articles underwent full text review and 10 studies involving 32,923 patients were included. The majority of the studies were of high quality according to NOS and RoB tools. Relapse proportions were 8±3%, 12±4%, and 14±6% at one, two, and four weeks, respectively. Female sex was the most common statistically significant reported factor associated with an increased risk of relapse within 4 weeks of ED discharge for acute asthma. Other factors significantly associated with relapse were past healthcare utilization and symptom duration. Conclusion: After ED management and discharge of acute asthma, a considerable proportion of patients will relapse within the first four weeks. Factors such as female sex, past healthcare utilization, and symptom duration were commonly and significantly associated with relapse occurrence. Identifying patients with these features could provide guidance to clinicians during the ED-discharge decision-making.

Introduction: Patients with asthma frequently present to the emergency department (ED) with exacerbations; however, a select number of patients require admission to hospital. The objective of this study was to summarize the evidence regarding asthma-related hospital admissions and factors associated with these admissions following ED presentation. Methods: Comprehensive literature searches were conducted in seven electronic databases (database inception to 2015); manual and grey literature searches were also performed. Studies reporting disposition for adults after ED presentation were included. Study quality was assessed using the Newcastle-Ottawa Scale (NOS); standardized data-collection forms were used for data extraction. Admission proportions and factors associated with admission at a statistical significance level (p<0.05) were reported. Results: Out of an initial 5865 identified articles, 37 articles met full inclusion criteria. Admission proportions were reported in 25/37 studies, ranged from 1% to 37%, and collectively demonstrated a decline of ~9% in admissions between 1993 and 2012. Studies including a >50% Caucasian ethnicity were found to have a median admission proportion of 13% (interquartile range [IQR]= 7, 20) versus studies with >50% non-Caucasian ethnicity at 22% (IQR=20, 28). Age, female sex, and previous hospitalizations for asthma exacerbation were the most individually identifiable factors associated with admission. Presenting features and medication profile were the most frequent domains associated with admission. Conclusion: Admission rates have decreased approximately 9% in a nearly 20-year span and seem to be higher in studies involving mostly non-Caucasian ethnic groups. Demographic factors, markers of severity obtained by history or at ED presentation, and medication profile could be assessed by ED clinicians to effectively discern patients at high risk for admission.