Urban ED Research Articles

Limitations of pulmonary embolism ICD-10 codes in emergency department administrative data: let the buyer beware

BackgroundAdministrative data is a useful tool for research and quality improvement; however, validity of research findings based on these data depends on their reliability. Diagnoses assigned by physicians are subsequently converted by nosologists to ICD-10 codes (International Statistical Classification of Diseases and Related Health Problems, 10th Revision). Several groups have reported ICD-9 coding errors in inpatient data that have implications for research, quality improvement, and policymaking, but few have assessed ICD-10 code validity in ambulatory care databases. Our objective was to evaluate pulmonary embolism (PE) ICD-10 code accuracy in our large, integrated hospital system, and the validity of using these codes for operational and health services research using ED ambulatory care databases.MethodsAmbulatory care data for patients (age ≥ 18 years) with a PE ICD-10 code (I26.0 and I26.9) were obtained from the records of four urban EDs between July 2013 to January 2015. PE diagnoses were confirmed by reviewing medical records and imaging reports. In cases where chart diagnosis and ICD-10 code were discrepant, chart review was considered correct. Physicians’ written discharge diagnoses were also searched using ‘pulmonary embolism’ and ‘PE’, and patients who were diagnosed with PE but not coded as PE were identified. Coding discrepancies were quantified and described.ResultsOne thousand, four hundred and fifty-three ED patients had a PE ICD-10 code. Of these, 257 (17.7%) were false positive, with an incorrectly assigned PE code. Among the 257 false positives, 193 cases had ambiguous ED diagnoses such as ‘rule out PE’ or ‘query PE’, while 64 cases should have had non-PE codes. An additional 117 patients (8.90%) with a PE discharge diagnosis were incorrectly assigned a non-PE ICD-10 code (false negative group). The sensitivity of PE ICD-10 codes in this dataset was 91.1% (95%CI, 89.4–92.6) with a specificity of 99.9% (95%CI, 99.9–99.9). The positive and negative predictive values were 82.3% (95%CI, 80.3–84.2) and 99.9% (95%CI, 99.9–99.9), respectively.ConclusionsAmbulatory care data, like inpatient data, are subject to coding errors. This confirms the importance of ICD-10 code validation prior to use. The largest proportion of coding errors arises from ambiguous physician documentation; therefore, physicians and data custodians must ensure that quality improvement processes are in place to promote ICD-10 coding accuracy.

A pre-operative clinical scoring system to distinguish perforation risk with pediatric appendicitis

ImportanceAppendicitis is a common, potentially serious pediatric disease. An important factor in determining management strategy [whether/when to perform appendectomy, duration of antibiotic therapy/hospitalization, etc.] and predicting outcome is distinguishing whether perforation is present. ObjectiveThe objective was to determine efficacy of commonly assessed pre-operative variables in stratifying perforation risk in children with appendicitis. DesignA retrospective analysis of consecutive cases was performed. SettingThe setting was a large urban hospital pediatric emergency department. ParticipantsFour hundred forty-eight consecutive cases of CT [computerized tomography]-confirmed pediatric appendicitis during a 6-year period in an urban pediatric ED [emergency department]: 162 with perforation and 286 non-perforated. Main outcome(s) and measure(s)To determine efficacy of clinical and laboratory variables with distinguishing perforation outcome in children with appendicitis. ResultsRegression analysis identified 3 independently significant variables associated with perforation outcome – and determined their ideal threshold values: duration of symptoms>1day; ED-measured fever [body temperature >38.0 °C]; CBC WBC absolute neutrophil count >13,000/mm3. The resulting multivariate ROC [receiver operating characteristic] curve after applying these threshold values gave an AUC [area under curve] of 89% for perforation outcome [p<0.001]. Risk for perforation was additive with each additional predictive variable exceeding its threshold value, linearly increasing from 7% with no variable present to 85% when all 3 variables are present. ConclusionsA pre-operative scoring system comprised of 3 commonly assessed clinical/laboratory variables is useful in stratifying perforation risk in children with appendicitis.Physicians can utilize these factors to gauge pre-operative risk for perforation in children with appendicitis, which can potentially aid in planning subsequent management strategy. Level of evidenceIII.

LO17: A comparative evaluation of ED crowding metrics and associations with patient mortality

Introduction: Over 700 different input, throughput and output metrics have been used to quantify ED crowding. Of these, only ED length-of-stay (ED LOS) has been shown to be associated with mortality. No comparative evaluation of ED crowding metrics has been performed to determine which ones have the strongest association with patient mortality. The objective of this study was to compare the strength of association of common ED input, throughput and output metrics to patient mortality. Methods: Administrative data from five years of ED visits (2011-2014) at three urban EDs were linked to develop a database of over 900,000 ED visits with patient demographics, electronic time stamps for care processes, dispositions and outcomes. The data were randomly divided into three partitions of equal size. Here we report the findings from one partition of 253,938 ED visits. The remaining two data partitions will be used to validate these findings. Commonly-used crowding metrics were quantified and aggregated by day or by shift (0800-1600, 1600-2400, 2400-0800), and the shift-specific metrics assigned to each patient. The primary outcome was 7-day all-cause mortality. Multilevel logistic regression models were developed for 7-day mortality, with selected ED crowding metrics and a common set of confounders as predictors. The strength of association between the crowding metrics and mortality was compared using Akaike’s Information Criterion (AIC) and the Bayesian Information Criterion (BIC): ED crowding metrics with lower AIC and BIC have stronger associations with 7-day mortality. Results: Of 909,000 ED encounters, 124,679 (16.5%) arrived by EMS, 149,233(19.7%) were admitted, and 3,808 patients (0.5%) died within 7 days of ED arrival. Of input metrics, the model with ED wait-time was better (i.e. had a smaller AIC and BIC) than models for daily census, ED occupancy or LWBS proportion for predicting 7-day mortality. Of throughput metrics, the model with mean ED LOS was better than the model for mean MD care time. Of output metrics, the model with daily inpatient hospital occupancy was better than the model with mean boarding time. Conclusion: Based on one data partition, regression models based on the average wait-time, ED LOS and inpatient occupancy best predicted 7-day mortality. These results will be validated in the two other data partitions to confirm the best-performing ED input, throughput and output metrics.

Describing wait time bottlenecks for ED patients undergoing head CT

Study objectivesFacing increased utilization and subsequent capacity and budget constraints, ED's must better understand bottlenecks and their effect on process flow to improve process efficiency. The primary objective of this study was to identify bottlenecks in obtaining a head CT and investigate patient waiting time based on those bottlenecks. MethodsThis observational study included all patients undergoing a head CT between July 1, 2013 and June 30, 2014 at a large, urban academic ED with over 100,000 visits per year.The primary study outcome was total cycle time, defined as the elapsed time between patient arrival and head CT preliminary report, divided into four components of workflow. Results8312 patients who had a head CT were included in this study. The median cycle time from patient arrival to head CT preliminary report was 3h and 13min with 39min of waiting time resulting from bottlenecks. In the 4-step model (time from patient arrival to head CT order, time from head CT order to head CT scheduled, time from head CT scheduled to head CT completed, and time from head CT completed to head CT preliminary report), each process was the bottleneck 30%, <1%, 27%, and 42% of the time, respectively. ConclusionDemand capacity mismatch in head CT scanning has a significant impact on patient waiting times. This study suggests opportunities to improve wait times through future research to understand the causes of delays in CT ordering, CT completion and timeliness of radiology reports.

LO85: Substantial variation in CTPE ordering patterns and diagnostic yield in a large group of specialty-trained emergency physicians

Introduction: Computerized tomography for pulmonary embolism (CTPE) has come under increased scrutiny with recommendations for evidence-based use found on Choosing Wisely lists in both Canada and the US. However practice variation in ordering patterns and diagnostic yield have not been well-reported for the Canadian context. Our objective was to investigate practice variation in CTPE ordering and rule-in rates within a large group of specialty-trained emergency physicians. Methods: We undertook an analysis of a computerized physician order entry database from four tertiary care EDs covering a 12-month period from August 1, 2016 to July 30, 2016 with 31 419 visits for potential pulmonary embolism (PE) as determined by a previously validated algorithm based on presenting complaints. CTPE utilization and diagnostic yield were determined for 149 physicians who ordered at least 10 studies over that time period. Outcomes of interest included CT utilization as determined by electronic order entry and a confirmed diagnosis of PE based on ICD-10 coding of the emergency visit. Descriptive statistics using medians, IQR and 95% confidence intervals are reported. This study is approved through REB14-0650 and is a component of a larger cluster RCT to improve CTPE utilization. Results: During the study period 2670 CTPE studies were ordered for potential PE patients representing 8.5% of the total with relevant complaints. We observed a 10-fold variation in CTPE ordering among physicians with rates as low as 2.7% and as high as 25%. The median rate of CTPE ordering for potential PE was 8.8% with an IQR of 6.0% to 11.7%. A total of 4146 CTPE studies were ordered during the study period with physicians ordering an average of 28 CTPE studies each; range 10-90. In terms of diagnostic yield, 591/4146 studies, or 14.3% (95% CI 13.2-15.3%) were associated with a diagnosis of PE. Diagnostic yield per physician ranged from 0 to 50%, with a median of 13.5% and an IQR of 7.6% to 21.4%. Conclusion: In this large, robust administrative dataset from four Canadian urban EDs, threshold for CTPE ordering varies widely among physicians as does diagnostic yield. Efforts to improve appropriate utilization are justified with an eye to reducing unnecessary radiation, costs and incidental findings.

MP16: Quality of work life among nurses and physicians in Québec rural emergency departments

Introduction: Recruitment and retention of healthcare staff are difficult in rural communities. Poor quality of work life (QWL) may be an underling factor as rural healthcare professionals are often isolated and work with limited resources. However, QWL data on rural emergency (ED) staff is limited. We assessed QWL among nurses and physicians as part of an ongoing study on ED care in Québec. Methods: We selected EDs offering 24/7 medical coverage, with hospitalization beds, in rural or small towns (Stats Canada definition). Of Québec’s 26 rural EDs, 23 (88%) agreed to participate. The online Quality of Work Life Systemic Inventory (QWLSI, with 1 item per 34 “life domains”), was sent to all non-locum ED nurses and physicians (about 500 potential participants). The QWLSI is used for comparing QWL scores to those of a large international database. We present overall and subscale QWL scores as percentiles (PCTL) of scores in the large database, and comparisons of nurses’ and physicians’ scores (t test). Results: Thirty-three physicians and 84 nurses participated. Mean age was 39.8 years (SD=10.1): physicians=37 (7.7) and nurses=40.9 (10.7). Overall QWL scores for all were in the 32nd PCTL, i.e. low. Nurses were in the 28th PCTL and physicians in the 44nd (p&amp;gt;0.05). For both groups, QWL was below the 25th PCTL i.e. very low, for “sharing workload during absence of an employee”, “working equipment”, “flexibility of work schedule”, “impact of working hours on health”, “possibility of being absent for familial reasons”, “relations with employees”. The groups differed (p&amp;lt;0.05) on only two subscales: remuneration and career path. For remuneration, scores were similar on fringe benefits (nurses 22nd PCTL, physicians 32nd) and income security (nurses 72nd, physicians 74th), but differed on income level (nurses 74th, physicians 93rd). The groups differed on all 3 career path items: advancement possibilities (nurses 53th, physicians 91st), possibilities for transfer (nurses 51nd, physicians 84th) and continuing education (nurses 18th, physicians 49th). Conclusion: Overall QWL among rural ED staff is poor. Groups had similar QWL scores except on career path, with physicians perceiving better long-term prospects. Given difficulties in rural recruitment and retention, these findings suggest that QWL should be assessed in rural and urban EDs nationwide.

De-labelling self-reported penicillin allergy within the emergency department through the use of skin tests and oral drug provocation testing.

Self-reported penicillin allergy is common among patients attending the ED, but is a poor predictor of true immunoglobulin E-mediated hypersensitivity to penicillin. We hypothesise that with a combination of skin testing and drug provocation testing, selected patients can be safely de-labelled of their allergy. This prospective study enrolled a sample of patients presenting to an urban academic ED between 2011 and 2016 with a self-reported allergy to penicillin. Standardised skin prick and intradermal testing with amoxicillin and both major and minor determinants of penicillin was performed in the department. If negative, testing was followed by a graded oral challenge of amoxicillin over 9 days. The primary end point was the allergy status of participants at the end of the study. A total of 100 patients (mean age 42; standard deviation 14 years; 54% women) completed the testing. Of these, 81% (95% confidence interval 71.9-88.2) showed no hypersensitivity to penicillin and were labelled non-allergic. The majority (16/19) of allergies were confirmed by skin testing, with three suspected allergies detected by the oral challenge. Women were more likely than men to have a true penicillin allergy, with odds ratio of 4.0 (95% confidence interval 1.23-13.2). There were no serious adverse events. Selected patients in the ED who self-report an allergy to penicillin can be safely tested there for penicillin allergy, using skin tests and oral drug provocation testing. This testing allows a significant de-labelling of penicillin allergy, with the majority of these patients able to tolerate penicillin without incident.

Marijuana use trajectories among drug-using youth presenting to an urban emergency department: Violence and social influences

AimsThis paper examined longitudinal marijuana use trajectories among drug-using youth presenting to the ED to inform intervention development. MethodsGiven interest in substance use and violence, this study oversampled those presenting with assault injuries. Assault-injured youth (ages 14–24) endorsing past 6-month drug use (n=349), and a sex and age proportionally-sampled comparison group (n=250) endorsing drug use, completed a baseline assessment and follow-ups at 6, 12, 18, and 24 months. Latent class trajectory analyses examined days of marijuana use over 2 years. Multinomial regression analyses examined baseline, 12-month and 24-month factors associated with substance use trajectory groups. ResultsTrajectory analyses identified 5 groups: Low (Low; 28.2%; n=169); Intermittent (INT; 16.2%; n=97); Moderate Decline (MD; 12.0%; n=72); High decline (HD, 13.2%; n=79) and Chronic (C; 30.4%; n=182). At baseline, as compared to the Low group, the other trajectory groups were more likely to be male and have greater levels of physical aggression. At 12- and 24-months, negative and positive peer influences, incarceration and community violence were additional characteristics associated with the greater marijuana use trajectories (as compared to the Low group). ConclusionsInterventions for drug-using youth presenting to the urban ED should address peer influences, physical aggression and community violence exposure, given the association between these characteristics and greater marijuana use trajectories.

Cocaine Versus Methamphetamine Users in the Emergency Department: How Do They Differ?

Background: Stimulant use disorder is a worldwide problem. Users present to the ED for diverse reasons including trauma, chest and abdominal pain, altered mental status, stroke, suicidality, and skin infection. Objective: To determine what differences exist between stimulant users. Methods: We compared Stimulant users presenting to an urban ED Level I trauma center over a 3-month period with toxicology screens positive for cocaine and/or methamphetamine. Results: Of 718 subjects (465 male, 253 female), 610 (85%) were positive for methamphetamine, 80 (11%) cocaine, and 28 (4%) both. Significant racial differences existed, but not for age, gender, and insurance status. Ethanol co-ingestion was higher for cocaine users, otherwise no significant differences were detected for laboratory values and maximum heart rate, and systolic/diastolic blood pressure. For presenting complaint, the proportion of cocaine users was higher for trauma and lower for altered level of consciousness than other subgroups. There was no significant difference in proportion of subjects admitted to the hospital, but cocaine users had a higher rate of elopement and were placed on 72-h psychiatric holds and/or transferred to inpatient psychiatric facilities at a significantly lower rate than the other subgroups. Conclusion: Cocaine users were more likely to present with trauma, elope from the ED, and have alcohol intoxication. Methamphetamine users were more likely to be Caucasian, have altered level of consciousness, be placed on psychiatric holds, or transferred to inpatient psychiatric facilities. These differences may be explained by regional preferences, socialization, personality types, and the unique neuropsychopharmacological differences between cocaine and methamphetamine.

Impact of an education session on clinical handover between medical shifts in an emergency department: A pilot study.

To evaluate the impact of a medical education session on the implementation of a new change of shift medical clinical handover format in an urban hospital ED. This pilot study used a pre- and post-intervention design. The intervention consisted of a 1 h education session to teach a new handover format, SBARM (Situation, Background, Assessment, Recommendation, Medication). Data were collected through observations of doctors performing clinical handover and individual interviews with participants. The educational intervention led to an increased focus on checking medication charts, but had minimal effect on changing other aspects of clinical handover at doctors' change of shift times. Perceived increased time spent on handover using the new system was seen as a major barrier to the implementation of SBARM. The addition of 'M' to 'SBAR' heightened awareness of checking medication and fluid charts. Time pressures need to be taken into consideration when introducing changes to current processes. Also, it is recommended that, in addition to ongoing education, senior clinicians are engaged during the planning and execution stages of changes to practice.

A randomised experiment comparing low-cost ultrasound gel alternative with commercial gel

ObjectivePoint-of-care ultrasound is a portable, relatively low-cost imaging modality with great potential utility in low-resource settings. However, commercially produced ultrasound gel is often cost-prohibitive and unavailable. We investigated whether images...

A determination of emergency department pre-triage times in patients not arriving by ambulance compared to widely used guideline recommendations.

Emergency department (ED) lengths of stay are measured from the time of patient registration or triage. The time that patients wait in line prior to registration and triage has not been well described. We sought to characterize pre-triage wait times and compare them to recommended physician response times, as per the Canadian Triage and Acuity Scale (CTAS). This observational study documented the time that consenting patients entered the ED and the time that they were formally registered and triaged. Participants' CTAS scores were collected from the electronic record. Patients arriving to the ED by ambulance were excluded. A total of 536 participants were timed over 13 separate intervals. Of these, 11 left without being triaged. Participants who scored either CTAS 1 or 2 (n=53) waited a median time of 3.1 (interquartile range [IQR]: 0.43, 11.1) minutes. Patients triaged as CTAS 3 (n=187) waited a median of 11.4 (IQR: 1.6, 24.9) minutes, CTAS 4 (n=139) a median of 16.6 (IQR: 6.0, 29.7) minutes, and CTAS 5 (n=146) a median of 17.5 (IQR: 6.8, 37.3) minutes. Of patients subsequently categorized as CTAS 1 or 2, 20.8% waited longer than the recommended time-to-physician of 15 minutes to be triaged. All urban EDs closely follow patients' wait times, often stratified according to triage category, which are assumed to be time-stamped upon a patient's arrival in the ED. We note that pre-triage times exceed the CTAS recommended time-to-physician in a possibly significant proportion of patients. EDs should consider documenting times to treatment from the moment of patient arrival rather than registration.

Low-acuity presentations to the emergency department in Canada: exploring the alternative attempts to avoid presentation

ObjectiveED visits have been rising year on year worldwide. It has been suggested that some of these visits could be avoided if low-acuity patients had better primary care access. This...

CONSULTUS INTERRUPTUS: UNSCHEDULED INTERACTIONS WITHIN THE EMERGENCY DEPARTMENT

IntroductionThe job of an EM consultant involves multitasking and dealing with multiple unscheduled interactions (UI). The fluid, unpredictable, time pressurised and multi-professional nature of EM makes it particularly susceptible to...

258 Identifying Medical Error in the Evaluation of Low and Intermediate Risk Chest Pain Patients

An ECG is a necessary tool in the evaluation of patients with suspected cardiac disease, although it is rarely diagnostic. We identify a form of medical error in the cardiac evaluation of patients. We performed a retrospective review of patients over the age of 35 receiving a cardiac evaluation in an urban ED from October, 2014 to October, 2015. Patients were identified in 2 cohorts; those with a chief complaint of chest pain (CP cohort) and all others (Atypical cohort) who received a cardiac evaluation (ECG or troponin) during their ED visit. By policy, the CP cohort was mandated to have an ECG ordered at triage. The Atypical cohort had the timing of the ECG left to clinical discretion. Medical error was defined as initiating a cardiac biomarker evaluation without ever obtaining an ECG. In a year, the CP cohort had 4,112 visits, 1,740 patients (42%) had biomarker evaluation, and 6 had a biomarker evaluation without an ECG (0.14% error rate). The Atypical cohort had 29,210 visits with ECG, 12,795 (44%) with biomarker evaluation, and 570 had a biomarker evaluation without an ECG (1.95% error rate), p=0.0001. All medical error in either cohort occurred when the clinician failed to use a chest pain order set. In the CP cohort, the error occurred first in not obtaining an ECG at triage; however, the clinician also failed to use the chest pain order set for evaluation. This data suggests that systematic error can be greatly reduced by the use of standardized CP order sets (in which an ECG is automatically ordered). Although the process error in our sample could be fixed by the use of order sets, measuring and addressing the cognitive error observed is far more difficult. The data calls into question how clinicians are using the ECG in low to intermediate risk CP if they failed to recognize in 2% of the patients that an ECG was never done.

138 Intermountain Risk Score is Highly Predictive of Pulmonary Embolism Mortality

The Intermountain Risk Score (IMRS) has proven to predict mortality in multiple patient groups. We sought to determine if it was predictive of mortality in patients with PE diagnosed in the emergency department. A retrospective chart review was performed on 3500 patients that had a computed tomography pulmonary angiogram (CTPA) performed for the workup of PE in two urban hospital EDs with a combined annual census of ∼120,000 patients between January 2009 and December 2010. We tracked recurrent (venothromboembolic events) VTE at 90-days and death at 90-days and 5-years. A total of 343 patients were enrolled following diagnosis of PE by CTPA in the ED between January 2009 and December 2010. 52% of patients were female and mean age was 55.41. At 90 days, women have mortality rates of 0.0% (0 deaths of n=98), 7.1% (4 deaths of n=56) and 15.0% (3 deaths of n=20) for low-, moderate-, and high-risk IMRS, respectively (p-trend<0.001). At 90 days, men have 0.0% (0 of n=84), 7.4% (4 deaths of n=54), and 11.8% (2 deaths of n=17) for low-, moderate-, and high-risk IMRS, respectively (p-trend=0.005). For recurrent VTE at 90 days the results were 4.2%, 5.6%, and 5.9% for females (p-trend=0.68) and 1.3%, 7.8%, and 5.9% for males (p-trend=0.12) for low-, moderate-, and high-risk IMRS. Mortality for the 5-year follow-up period produced similar results (0%, 11.5%, and 38.7% death for females, p<0.001; and 6.8%, 21.7%, 75.0% death for males, p<0.001). The IMRS is highly predictive of both 90-day and 5-year all cause mortality in PE patients.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Patient Insurance Profiles: A Tertiary Care Compared to Three Freestanding Emergency Departments

BackgroundIt has been speculated that freestanding emergency departments (FEDs) draw more affluent, better-insured patients away from urban hospital EDs. It is believed that this leaves urban hospital−based EDs less financially secure. ObjectiveWe examined whether the distribution of patients with four types of insurance (self-pay, Medicaid, Medicare, and private) at the main ED changed after opening three affiliated FEDs, and whether the insurance type distribution was different between main ED and FEDs and between individual FEDs. MethodsA retrospective analysis of insurance status of all patients presenting to our EDs from July 2006 through August 2013. Insurance was divided into self-pay, Medicare, Medicaid, and private insurance across three time periods, which reflect the sequential opening of each FED. Insurance types for each facility were compared for individual time periods and across time periods. χ2 was used to analyze the data. ResultsIn the three studied time frames (periods B, C, and D), there were less privately insured patients and more self-pay, Medicaid, and Medicare patients at the main than at each FED (p < 0.001). Insurance types were significantly different between each of the three FEDs and the main ED (p < 0.001) and between each of the three FEDs (p < 0.001). ConclusionsThere were less privately insured patients and more self-pay, Medicaid, and Medicare patients at the main ED compared to the FEDs. Privately insured patients decreased at both the FEDs and main ED during the study. Insurance distribution was significantly different between the main ED, and three FEDs, and between individual FEDs.

Suicidal Ideation After Mild Traumatic Brain Injury: A Consecutive Canadian Sample

This study aims to elucidate psychosocial and injury features contributing to SI following concussion or mild traumatic brain injury (mTBI) and the time course for its development. Between 1998 and 2012, a sample of 871 patients referred to a follow-up clinic after concussion treatment in an urban tertiary care ED were consecutively offered enrollment at 3 months post injury. Data from psychiatric and social-demographic assessments were consecutively collected at 2 visits (3 and 6 months after injury) respectively. Chi-square and t-tests were performed to identify associations between variables related with SI. Logistic regression analysis was performed to identify factors independently associated. During the enrolment period, 2,296 patients with mTBI presented to the ED. 871 adults completed psychiatric and social demographic clinic assessments at 3 months, and 500 returned at 6 months. Suicidal ideation was expressed by 6.3% at 3 months and 8.2% at 6 months. Regression models showed SI independently associated with: speaking English as a second language (ESL) and injury mechanism (MVC passenger) at 3 and 6 months; and history of depression and marital status at 3 months only. SI is common 3 months after mTBI, and appears more at 6 month follow up. These findings suggest earlier screening for predisposing factors and closer monitoring of those at risk for suicidality.

LO066: H1-antihistamine administration is associated with a lower likelihood of progression to anaphylaxis among emergency department patients with allergic reactions

Introduction: H1-antihistamines are often used to treat allergic reactions, however, the influence of H1-antihistamines on progression to anaphylaxis remains unclear. Among patients initially presenting with allergic reactions, we investigated whether H1-antihistamines were associated with a lower proportion of patients progressing to anaphylaxis during observation. Methods: This was a retrospective cohort study conducted at two urban EDs from 2007 to 2012. We included adult patients with allergy and excluded those who met criteria of anaphylaxis at first evaluation by medical professionals and/or received antihistamines before the evaluation. Primary outcomes of interest were the number of patients who developed anaphylaxis during observation at ED and/or transportation by EMS. Secondary outcomes were the number of biphasic reactions and severe anaphylaxis (defined as sBP&lt;90; SpO2&lt;92%; and/or confusion, collapse, loss of conscious, or incontinence). Logistic regression was performed comparing primary and secondary outcomes between H1-antihistamine treated and non-treated groups with propensity score adjustment of the baseline covariates. Number needed to treat (NNT) was calculated by adjusted absolute risk reduction of H1-antihistamine compared to non H1-antihistamine use on primary outcome. Results: This study included 1717 patients with allergic reactions, of whom 1228 were treated with H1-antihistamines. In the H1-antihistamine group 1.0% and 0.2% developed anaphylaxis and severe anaphylaxis, respectively; in the non-H1-antihistamine group 2.6% and 0.6% developed anaphylaxis and severe anaphylaxis, respectively. There were no biphasic reactions (0%, 95% confidence interval [CI] 0 to 0.17%). Administration of H1-antihistamines was associated with a lower incidence of subsequent anaphylaxis (adjusted odds ratio [OR] 0.23, 95% CI 0.10 to 0.53; NNT to benefit 49.1, 95% CI 41.6 to 83.3). There were no significant associations between H1-histamines administration and secondary outcomes. Conclusion: Among ED patient with allergic reactions, H1-antihistamine administration was associated with a lower likelihood of progression to anaphylaxis. These findings suggest that H1-antihistamines should be administered early in the care of patients with allergic reactions.

MP025: Does your patient really need intravenous therapy? A multicenter variation analysis of physician practice in low-acuity presentations

Introduction: The decision to treat with parenteral therapy may reflect a variable practice pattern among emergency physicians and represent an opportunity to standardize care. Our objective was to describe physician level practice variation for IV therapies in patients with low-acuity presentations and quantify the contribution of IV therapy to prolonging ED LOS. Methods: Using administrative data merged with computerized physician order entry information we sampled 48 months of patient variables across four urban EDs (Jan 1, 2014 - Dec 22, 2015). Eligible patients: 1. presented with complaints of abdominal pain, nausea and vomiting or diarrhea or had a discharge diagnosis of cellulitis 2.were in a low acuity category (Canadian Triage and Acuity Scale - CTAS 3 or 4) 3.were triaged to non-stretcher zones of the ED and 4.were not admitted to hospital. The primary outcome was the physician-level variation in the decision to order IV therapies for this patient group; namely one or more of the following: IV fluids, opioid analgesia, anti-emetics and antibiotics. Secondary outcomes were a comparison of ED LOS, ED revisits at 7 days and ED revisits resulting in admission at 7 days for the IV and non-IV groups. Results: Our analysis included 31 802 patient visits treated by 185 physicians. The average patient age was 37.8 years with 64.3% being female and the majority triaged as CTAS 3 (82.5%). On average 24% of these visits were treated with IV therapies; 90th percentile; 34%. For physicians seeing in excess of 100 cases, the variation in IV therapy use ranged from 1% to 47%. Patients receiving IV therapies demonstrated a 44% greater average LOS (6.2 hours vs 4.3 hours) and those receiving IV therapies had higher 7-day ED revisit rates (12.0% vs 8.8%) as well as 7-day ED revisits resulting in readmission (2.4% vs 1.0%). 'mso-spacerun:yes'&gt; Secondary outcomes were a comparison of ED LOS, ED revisits at 7 days and ED revisits resulting in admission at 7 days for the IV and non-IV groups. Conclusion: This is the first study to examine physician preference for the use of IV therapies in a low-acuity population and has demonstrated in excess of a 47-fold variation between both extremes of use. Reducing practice variation in this area of ED care by standardizing indications for IV therapies could result in more rational resource utilization and improved throughput.