An all-inclusive model for predicting invasive bacterial infection in febrile infants age 7-60 days

BACKGROUND

Invasive bacterial infections (IBIs) in febrile infants are rare but potentially devastating. We aimed to derive and validate a predictive model for IBI among febrile infants age 7-60 days.

METHODS

Data were abstracted retrospectively from electronic records of 37 emergency departments (EDs) for infants with a measured temperature >=100.4 F who underwent an ED evaluation with blood and urine cultures. Models to predict IBI were developed and validated respectively using a random 80/20 dataset split, including 10-fold cross-validation. We used precision recall curves as the classification metric.

RESULTS

Of 4411 eligible infants with a mean age of 37 days, 29% had characteristics that would likely have excluded them from existing risk stratification protocols. There were 196 patients with IBI (4.4%), including 43 (1.0%) with bacterial meningitis. Analytic approaches varied in performance characteristics (precision recall range 0.04-0.29, area under the curve range 0.5-0.84), with the XGBoost model demonstrating the best performance (0.29, 0.84). The five most important variables were serum white blood count, maximum temperature, absolute neutrophil count, absolute band count, and age in days.

CONCLUSION

A machine learning model (XGBoost) demonstrated the best performance in predicting a rare outcome among febrile infants, including those excluded from existing algorithms.

IMPACT

Several models for the risk stratification of febrile infants have been developed. There is a need for a preferred comprehensive model free from limitations and algorithm exclusions that accurately predicts IBIs. This is the first study to derive an all-inclusive predictive model for febrile infants aged 7-60 days in a community ED sample with IBI as a primary outcome. This machine learning model demonstrates potential for clinical utility in predicting IBI.

Shifts in Diagnostic Testing for Headache in the Emergency Department, 2015 to 2021

Importance

Subarachnoid hemorrhage is typically diagnosed by noncontrast head computed tomography (CT); lumbar puncture is recommended if computed tomography is nondiagnostic, although CT cerebral angiography has been promoted as an alternative to lumbar puncture in this diagnostic pathway. The outcomes of this debate in practice have not been studied.

Objective

To determine whether CT cerebral angiography use has increased in lieu of lumbar puncture among emergency department (ED) patients with headache, with an increase in unruptured intracranial aneurysm detection.

Design, Setting, and Participants

This retrospective cohort study took place in 21 community EDs of an integrated health care system in Northern California between 2015 and 2021. Participants were adult (aged >17 years) health plan members with a chief concern of headache. Exclusions were prior diagnoses of subarachnoid hemorrhage, unruptured intracranial aneurysm, cerebral arteriovenous malformation, or cerebrospinal fluid shunt. Data were analyzed from October to November 2023.

Exposures

CT cerebral angiography and/or lumbar puncture during the ED encounter.

Main Outcomes and Measures

Primary and secondary outcomes were 14-day and 90-day unruptured intracranial aneurysm detection, respectively. Safety outcomes were missed diagnoses of subarachnoid hemorrhage or bacterial meningitis. The annual incidence of unruptured intracranial aneurysm detection was normalized to the incidence of subarachnoid hemorrhage (UIA:SAH ratio). Average annualized percentage changes were quantified using joinpoint regression analysis.

Results

Among 198 109 included ED encounters, the mean (SD) age was 47.5 (18.4) years; 140 001 patients (70.7%) were female; 29 035 (14.7%) were Black or African American, 59 896 (30.2%) were Hispanic or Latino, and 75 602 (38.2%) were White. Per year, CT cerebral angiography use increased (18.8%; 95% CI, 17.7% to 20.3%) and lumbar punctures decreased (-11.1%; 95% CI, -12.0% to -10.4%), with a corresponding increase in the 14-day UIA:SAH ratio (3.5%; 95% CI, 0.9% to 7.4%). Overall, computed tomography cerebral angiography use increased 6-fold relative to lumbar puncture, with a 33% increase in the detection of UIA. Results were similar at 90 days and robust to sensitivity analyses. Subarachnoid hemorrhage (1004 cases) and bacterial meningitis (118 cases) were misdiagnosed in 5% and 18% of cases, respectively, with no annual trends (P = .34; z1003 = .95 and P = .74; z117 = -.34, respectively).

Conclusions and Relevance

In this cohort study of ED patients with headache, increases in CT cerebral angiography use were associated with fewer lumbar punctures and higher detection of unruptured intracranial aneurysms, with no significant change in missed diagnoses of subarachnoid hemorrhage or bacterial meningitis. While this shift in diagnostic strategy appeared safe in the short-term, the long-term consequences remain unclear.

Clinical outcomes in hospitalized plasma and platelet transfusion recipients prior to and following widespread blood donor SARS-CoV-2 infection and vaccination

BACKGROUND

The safety of transfusion of SARS-CoV-2 antibodies in high plasma volume blood components to recipients without COVID-19 is not established. We assessed whether transfusion of plasma or platelet products during periods of increasing prevalence of blood donor SARS-CoV-2 infection and vaccination was associated with changes in outcomes in hospitalized patients without COVID-19.

METHODS

We conducted a retrospective cohort study of hospitalized adults who received plasma or platelet transfusions at 21 hospitals during pre-COVID-19 (3/1/2018-2/29/2020), COVID-19 pre-vaccine (3/1/2020-2/28/2021), and COVID-19 post-vaccine (3/1/2021-8/31/2022) study periods. We used multivariable logistic regression with generalized estimating equations to adjust for demographics and comorbidities to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Among 21,750 hospitalizations of 18,584 transfusion recipients without COVID-19, there were 697 post-transfusion thrombotic events, and oxygen requirements were increased in 1751 hospitalizations. Intensive care unit length of stay (n = 11,683) was 3 days (interquartile range 1-5), hospital mortality occurred in 3223 (14.8%), and 30-day rehospitalization in 4144 (23.7%). Comparing the pre-COVID, pre-vaccine and post-vaccine study periods, there were no trends in thromboses (OR 0.9 [95% CI 0.8, 1.1]; p = .22) or oxygen requirements (OR 1.0 [95% CI 0.9, 1.1]; p = .41). In parallel, there were no trends across study periods for ICU length of stay (p = .83), adjusted hospital mortality (OR 1.0 [95% CI 0.9-1.0]; p = .36), or 30-day rehospitalization (p = .29).

DISCUSSION

Transfusion of plasma and platelet blood components collected during the pre-vaccine and post-vaccine periods of the COVID-19 pandemic was not associated with increased adverse outcomes in transfusion recipients without COVID-19.

Physicians' Perceptions of Clinical Decision Support to Treat Patients With Heart Failure in the ED

Importance

Clinical decision support (CDS) could help emergency department (ED) physicians treat patients with heart failure (HF) by estimating risk, collating relevant history, and assisting with medication prescribing if physicians' perspectives inform its design and implementation.

Objective

To evaluate CDS usability and workflow integration in the hands of ED physician end users who use it in clinical practice.

Design, Setting, and Participants

This mixed-methods qualitative study administered semistructured interviews to ED physicians from 2 community EDs of Kaiser Permanente Northern California in 2023. The interview guide, based on the Usability Heuristics for User Interface Design and the Sociotechnical Environment models, yielded themes used to construct an electronic survey instrument sent to all ED physicians.

Main Outcomes and Measures

Main outcomes were physicians' perceptions of using CDS to complement clinical decision-making, usability, and integration into ED clinical workflow.

Results

Seven key informant physicians (5 [71.4%] female, median [IQR] 15.0 [9.5-15.0] years in practice) were interviewed and survey responses from 51 physicians (23 [45.1%] female, median [IQR] 14.0 [9.5-17.0] years in practice) were received from EDs piloting the CDS intervention. Response rate was 67.1% (51 of 76). Physicians suggested changes to CDS accessibility, functionality, and workflow integration. Most agreed that CDS would improve patient care and fewer than half of physicians expressed hesitation about their capacity to consistently comply with its recommendations, citing workload concerns. Physicians preferred a passive prompt that encouraged, but did not mandate, interaction with the CDS.

Conclusions and Relevance

In this qualitative study of physicians who were using a novel CDS intervention to assist with ED management of patients with acute HF, several opportunities were identified to improve usability as well as several key barriers and facilitators to CDS implementation.

CA FIRST (California Febrile Infant Risk Stratification Tool) Algorithm Development in a Learning Health System

Introduction There is considerable variation in the approach to infants presenting to the emergency department (ED) with fever. The authors' primary aim was to develop a robust set of algorithms using community ED data to inform modifications of broader clinical guidance. Methods The authors report the development of California Febrile Infant Risk Stratification Tool (CA FIRST) using key components of the Roseville Protocol (ROS) and American Academy of Pediatrics (AAP) Clinical Practice Guideline (CPG). Expanded guidance was derived using a retrospective analysis of a cohort of 3527 febrile infants aged 7-90 days presenting to any Kaiser Permanente Northern California ED between 2010 and 2019 who underwent a core febrile infant evaluation. Results Melding ROS and AAP CPG algorithms in infants 7-60 days old, CA FIRST Algorithms had comparable performance characteristics to ROS and AAP CPG. CA FIRST enhancements included guidance on febrile infants 61-90 days old, high-risk infants, infants with bronchiolitis, and infants who received immunizations within the prior 48 hours. This retrospective analysis revealed that of 235 febrile infants 22-90 days old with respiratory syncytial virus and 221 who had fever in the 48 hours following vaccination, there were no cases of invasive bacterial infection. Discussion CA FIRST is a set of 13 algorithms providing a thoughtful and flexible approach to the febrile infant while minimizing unnecessary interventions. Conclusions CA FIRST Algorithms empower clinicians to manage most febrile infants. Algorithms are being modified as new data become available, imparting useful and ever-current educational information within a learning health care system.

Automated analysis of unstructured clinical assessments improves emergency department triage performance: A retrospective deep learning analysis

Objectives

Efficient and accurate emergency department (ED) triage is critical to prioritize the sickest patients and manage department flow. We explored the use of electronic health record data and advanced predictive analytics to improve triage performance.

Methods

Using a data set of over 5 million ED encounters of patients 18 years and older across 21 EDs from 2016 to 2020, we derived triage models using deep learning to predict 2 outcomes: hospitalization (primary outcome) and fast-track eligibility (exploratory outcome), defined as ED discharge with <2 resource types used (eg, laboratory or imaging studies) and no critical events (eg, resuscitative medications use or intensive care unit [ICU] admission). We report area under the receiver operator characteristic curve (AUC) and 95% confidence intervals (CI) for models using (1) triage variables alone (demographics and vital signs), (2) triage nurse clinical assessment alone (unstructured notes), and (3) triage variables plus clinical assessment for each prediction target.

Results

We found 12.7% of patients were hospitalized (n = 673,659) and 37.0% were fast-track eligible (n = 1,966,615). The AUC was lowest for models using triage variables alone: AUC 0.77 (95% CI 0.77-0.78) and 0.70 (95% CI 0.70-0.71) for hospitalization and fast-track eligibility, respectively, and highest for models incorporating clinical assessment with triage variables for both hospitalization and fast-track eligibility: AUC 0.87 (95% CI 0.87-0.87) for both prediction targets.

Conclusion

Our findings highlight the potential to use advanced predictive analytics to accurately predict key ED triage outcomes. Predictive accuracy was optimized when clinical assessments were added to models using simple structured variables alone.

Mortality Following Diagnosis of Nontraumatic Intracerebral Hemorrhage Within an Integrated "Hub-and-Spoke" Neuroscience Care Model: Is Spoke Presentation Noninferior to Hub Presentation?

BACKGROUND

Practice guidelines recommend that patients with intracerebral hemorrhage (ICH) be treated in units with acute neuroscience care experience. However, most hospitals in the United States lack this degree of specialization. We sought to examine outcome differences for patients with nontraumatic ICH presenting to centers with and without advanced neuroscience care specialization.

METHODS

This was a retrospective study of adult patients presenting with nontraumatic ICH between 1/1/2011 and 9/30/2020 across 21 medical centers within Kaiser Permanente Northern California, an integrated care system that employs a "hub-and-spoke" model of neuroscience care in which two centers service as neuroscience "hubs" and the remaining 19 centers service as referral "spokes." Patients presenting to spokes can receive remote consultation (including image review) by neurosurgical or neurointensive care specialists located at hubs. The primary outcome was 90-day mortality. We used hierarchical logistic regression, adjusting for ICH score components, comorbidities, and demographics, to test a hypothesis that initial presentation to a spoke medical center was noninferior to hub presentation [defined as an odds ratio (OR) with an upper 95% confidence interval (CI) limit of 1.24 or less].

RESULTS

A total of 6978 patients were included, with 6170 (88%) initially presenting to spoke medical centers. The unadjusted 90-day mortality for patients initially presenting to spoke versus hub medical centers was 32.2% and 32.7%, respectively. In adjusted analysis, presentation to a spoke medical center was neither noninferior nor inferior for 90-day mortality risk (OR 1.21, 95% CI 0.84-1.74). Sensitivity analysis excluding patients admitted to general wards or lacking continuous health plan insurance during the follow-up period trended closer to a noninferior result (OR 0.99, 95% CI 0.69-1.44).

CONCLUSIONS

Within an integrated "hub-and-spoke" neuroscience care model, the risk of 90-day mortality following initial presentation with nontraumatic ICH to a spoke medical center was not conclusively noninferior compared with initial presentation to a hub medical center. However, there was also no indication that care for selected patients with nontraumatic ICH within medical centers lacking advanced neuroscience specialization resulted in significantly inferior outcomes. This finding may support the safety and efficiency of a "hub-and-spoke" care model for patients with nontraumatic ICH, although additional investigations are warranted.

Clinical decision support to Optimize Care of patients with Atrial Fibrillation or flutter in the Emergency department: protocol of a stepped-wedge cluster randomized pragmatic trial (O'CAFÉ trial)

BACKGROUND

Management of adults with atrial fibrillation (AF) or atrial flutter in the emergency department (ED) includes rate reduction, cardioversion, and stroke prevention. Different approaches to these components of care may lead to variation in frequency of hospitalization and stroke prevention actions, with significant implications for patient experience, cost of care, and risk of complications. Standardization using evidence-based recommendations could reduce variation in management, preventable hospitalizations, and stroke risk.

METHODS

We describe the rationale for our ED-based AF treatment recommendations. We also describe the development of an electronic clinical decision support system (CDSS) to deliver these recommendations to emergency physicians at the point of care. We implemented the CDSS at three pilot sites to assess feasibility and solicit user feedback. We will evaluate the impact of the CDSS on hospitalization and stroke prevention actions using a stepped-wedge cluster randomized pragmatic clinical trial across 13 community EDs in Northern California.

DISCUSSION

We hypothesize that the CDSS intervention will reduce hospitalization of adults with isolated AF or atrial flutter presenting to the ED and increase anticoagulation prescription in eligible patients at the time of ED discharge and within 30 days. If our hypotheses are confirmed, the treatment protocol and CDSS could be recommended to other EDs to improve management of adults with AF or atrial flutter.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05009225 .  Registered on 17 August 2021.

Evaluation of the Emergency Severity Index in US Emergency Departments for the Rate of Mistriage

IMPORTANCE

Accurate emergency department (ED) triage is essential to prioritize the most critically ill patients and distribute resources appropriately. The most used triage system in the US is the Emergency Severity Index (ESI).

OBJECTIVES

To derive and validate an algorithm to assess the rate of mistriage and to identify characteristics associated with mistriage.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study created operational definitions for each ESI level that use ED visit electronic health record data to classify encounters as undertriaged, overtriaged, or correctly triaged. These definitions were applied to a retrospective cohort to assess variation in triage accuracy by facility and patient characteristics in 21 EDs within the Kaiser Permanente Northern California (KPNC) health care system. All ED encounters by patients 18 years and older between January 1, 2016, and December 31, 2020, were assessed for eligibility. Encounters with missing ESI or incomplete ED time variables and patients who left against medical advice or without being seen were excluded. Data were analyzed between January 1, 2021, and November 30, 2022.

EXPOSURES

Assigned ESI level.

MAIN OUTCOMES AND MEASURES

Rate of undertriage and overtriage by assigned ESI level based on a mistriage algorithm and patient and visit characteristics associated with undertriage and overtriage.

RESULTS

A total of 5 315 176 ED encounters were included. The mean (SD) patient age was 52 (21) years; 44.3% of patients were men and 55.7% were women. In terms of race and ethnicity, 11.1% of participants were Asian, 15.1% were Black, 21.4% were Hispanic, 44.0% were non-Hispanic White, and 8.5% were of other (includes American Indian or Alaska Native, Native Hawaiian or other Pacific Islander, and multiple races or ethnicities), unknown, or missing race or ethnicity. Mistriage occurred in 1 713 260 encounters (32.2%), of which 176 131 (3.3%) were undertriaged and 1 537 129 (28.9%) were overtriaged. The sensitivity of ESI to identify a patient with high-acuity illness (correctly assigning ESI I or II among patients who had a life-stabilizing intervention) was 65.9%. In adjusted analyses, Black patients had a 4.6% (95% CI, 4.3%-4.9%) greater relative risk of overtriage and an 18.5% (95% CI, 16.9%-20.0%) greater relative risk of undertriage compared with White patients, while Black male patients had a 9.9% (95% CI, 9.8%-10.0%) greater relative risk of overtriage and a 41.0% (95% CI, 40.0%-41.9%) greater relative risk of undertriage compared with White female patients. High relative risk of undertriage was found among patients taking high-risk medications (30.3% [95% CI, 28.3%-32.4%]) and those with a greater comorbidity burden (22.4% [95% CI, 20.1%-24.4%]) and recent intensive care unit utilization (36.7% [95% CI, 30.5%-41.4%]).

CONCLUSIONS AND RELEVANCE

In this retrospective cohort study of over 5 million ED encounters, mistriage with ESI was common. Quality improvement should focus on limiting critical undertriage, optimizing resource allocation by patient need, and promoting equity.

Using AAP Guidelines for Managing Febrile Infants Without C-Reactive Protein and Procalcitonin

BACKGROUND AND OBJECTIVES

In 2021, the American Academy of Pediatrics (AAP) published the Clinical Practice Guideline (CPG) for management of well-appearing, febrile infants 8 to 60 days old. For older infants, the guideline relies on several inflammatory markers, including tests not rapidly available in many settings like C-reactive protein (CRP) and procalcitonin (PCT). This study describes the performance of the AAP CPG for detecting invasive bacterial infections (IBI) without using CRP and PCT.

METHODS

This retrospective cohort study included infants aged 8 to 60 days old presenting to Kaiser Permanente Northern California emergency departments between 2010 and 2019 with temperatures ≥38°C who met AAP CPG inclusion criteria and underwent complete blood counts, blood cultures, and urinalyses. Performance characteristics for detecting IBI were calculated for each age group.

RESULTS

Among 1433 eligible infants, there were 57 (4.0%) bacteremia and 9 (0.6%) bacterial meningitis cases. Using absolute neutrophil count >5200/mm3 and temperature >38.5°C as inflammatory markers, 3 (5%) infants with IBI were misidentified. Sensitivities and specificities for detecting infants with IBIs in each age group were: 8 to 21 days: 100% (95% confidence interval [CI] 83.9%-100%) and 0% (95% CI 0%-1.4%); 22 to 28 days: 88.9% (95% CI 51.8%-99.7%) and 40.4% (95% CI 33.2%- 48.1%); and 29 to 60 days: 93.3% (95% CI 77.9%-99.2%) and 32.1% (95% CI 29.1%- 35.3%). Invasive interventions were recommended for 100% of infants aged 8 to 21 days; 58% to 100% of infants aged 22 to 28 days; and 0% to 69% of infants aged 29 to 60 days.

CONCLUSIONS

When CRP and PCT are not available, the AAP CPG detected IBI in young, febrile infants with high sensitivity but low specificity.

Management and Outcomes of Adults Diagnosed with Acute Pulmonary Embolism in Primary Care: Community-Based Retrospective Cohort Study

BACKGROUND

The management and outcomes of patients diagnosed with acute pulmonary embolism in primary care have not been characterized.

OBJECTIVE

To describe 30-day outcomes stratified by initial site-of-care decisions DESIGN: Multicenter retrospective cohort study PARTICIPANTS: Adults diagnosed with acute pulmonary embolism in primary care in a large, diverse community-based US health system (2013-2019) MAIN MEASURES: The primary outcome was a composite of 30-day serious adverse events (recurrent venous thromboembolism, major bleeding, and all-cause mortality). The secondary outcome was 7-day pulmonary embolism-related hospitalization, either initial or delayed.

KEY RESULTS

Among 652 patient encounters (from 646 patients), median age was 64 years; 51.5% were male and 70.7% identified as non-Hispanic white. Overall, 134 cases (20.6%) were sent home from primary care and 518 cases (79.4%) were initially referred to the emergency department (ED) or hospital. Among the referred, 196 (37.8%) were discharged home from the ED without events. Eight patients (1.2%; 95% CI 0.5-2.4%) experienced a 30-day serious adverse event: 4 venous thromboemboli (0.6%), 1 major bleed (0.2%), and 3 deaths (0.5%). Seven of these patients were initially hospitalized, and 1 had been sent home from primary care. All 3 deaths occurred in patients with known metastatic cancer initially referred to the ED, hospitalized, then enrolled in hospice following discharge. Overall, 328 patients (50.3%) were hospitalized within 7 days: 322 at the time of the index diagnosis and 6 following initial outpatient management (4 clinic-only and 2 clinic-plus-ED patients).

CONCLUSIONS

Patients diagnosed with acute pulmonary embolism in this primary care setting uncommonly experienced 30-day adverse events, regardless of initial site-of-care decisions. Over 20% were managed comprehensively by primary care. Delayed 7-day pulmonary embolism-related hospitalization was rare among the 51% treated as outpatients. Primary care management of acute pulmonary embolism appears to be safe and could have implications for cost-effectiveness and patient care experience.

Barriers and Opportunities Regarding Implementation of a Machine Learning-Based Acute Heart Failure Risk Stratification Tool in the Emergency Department

Hospital admissions for patients with acute heart failure (AHF) remain high. There is an opportunity to improve alignment between patient risk and admission decision. We recently developed a machine learning (ML)-based model that stratifies emergency department (ED) patients with AHF based on predicted risk of a 30-day severe adverse event. Prior to deploying the algorithm and paired clinical decision support, we sought to understand barriers and opportunities regarding successful implementation. We conducted semi-structured interviews with eight front-line ED providers and surveyed 67 ED providers. Audio-recorded interviews were transcribed and analyzed using thematic analysis, and we had a 65% response rate to the survey. Providers wanted decision support to be streamlined into workflows with minimal disruptions. Most providers wanted assistance primarily with ED disposition decisions, and secondarily with medical management and post-discharge follow-up care. Receiving feedback on patient outcomes after risk tool use was seen as an opportunity to increase acceptance, and few providers (<10%) had significant hesitations with using an ML-based tool after education on its use. Engagement with key front-line users on optimal design of the algorithm and decision support may contribute to broader uptake, acceptance, and adoption of recommendations for clinical decisions.

Risk adjusted 30‐day mortality and serious adverse event rates among a large, multi‐center cohort of emergency department patients with acute heart failure

Background

Admission rates for emergency department (ED) patients with acute heart failure (AHF) remain elevated. Use of a risk stratification tool could improve disposition decision making by identifying low‐risk patients who may be safe for outpatient management.

Methods

We performed a secondary analysis of a retrospective, multi‐center cohort of 26,189 ED patients treated for AHF from January 1, 2017 to December 31, 2018. We applied a 30‐day risk model we previously developed and grouped patients into 4 categories (low, low/moderate, moderate, and high) of predicted 30‐day risk of a serious adverse event (SAE). SAE consisted of death or cardiopulmonary resuscitation (CPR), intra‐aorta balloon pump, endotracheal intubation, renal failure requiring dialysis, or acute coronary syndrome. We measured the 30‐day mortality and composite SAE rates among patients by risk category according to ED disposition: direct discharge, discharge after observation, and hospital admission.

Results

The observed 30‐day mortality and total SAE rates were less than 1% and 2%, respectively, among 25% of patients in the low and low/moderate risk groups. These rates did not vary significantly by ED disposition. An additional 23% of patients were moderate risk and experienced an approximate 2% 30‐day mortality rate.

Conclusion

Use of a risk stratification tool could help identify lower risk AHF patients who may be appropriate for ED discharge. These findings will help inform prospective testing to determine how this risk tool can augment ED decision making.

Higher intensity of 72-h noninvasive cardiac test referral does not improve short-term outcomes among emergency department patients with chest pain

BACKGROUND

It is unclear whether referral for cardiac noninvasive testing (NIT) following emergency department (ED) chest pain encounters improves short-term outcomes.

METHODS

This was a retrospective cohort study of patients presenting with chest pain, without ST-elevation myocardial infarction or myocardial injury by serum troponin testing, between 2013 and 2019 to 21 EDs within an integrated health care system. We examined the association between NIT referral (within 72 h of the ED encounter) and a primary outcome of 60-day major adverse cardiac events (MACE). Secondary outcomes were 60-day MACE without coronary revascularization (MACE-CR) and 60-day all-cause mortality. To account for confounding by indication for NIT, we grouped patient encounters into ranked tertiles of NIT referral intensity based on the likelihood of 72-h NIT referral associated with the initially assigned emergency physician, relative to local peers and within discrete time periods. Associations between NIT referral-intensity tertile and outcomes were assessed using risk-adjusted multivariable logistic regression.

RESULTS

Among 210,948 eligible patient encounters, 72-h NIT referral frequency was 11.9%, 18.3%, and 25.9% in low, intermediate, and high NIT referral-intensity encounters, respectively. Compared with the low referral-intensity tertile, there was a higher risk of 60-day MACE within the high referral-intensity tertile (odds ratio [OR] = 1.11, 95% confidence interval [CI] = 1.04 to 1.17) due to more coronary revascularizations without corresponding differences in MACE-CR or all-cause mortality. In analyses stratified by patients' estimated risk (HEART score; 50.5% lower risk, 38.7% moderate risk, 10.8% higher risk), the difference in 60-day MACE was primarily attributable to moderate-risk encounters (OR = 1.15, 95% CI = 1.08 to 1.24), with no differences among either lower- (OR = 1.10, 95% CI = 0.92 to 1.31) or higher- (OR = 1.01, 95% CI = 0.90 to 1.14) risk encounters.

CONCLUSION

Higher referral intensity for 72-h NIT was associated with higher risk of coronary revascularization but no difference in adverse events within 60 days. These findings further call into question the urgency of NIT among ED patients without objective evidence of myocardial injury.

Graded Coronary Risk Stratification for Emergency Department Patients With Chest Pain: A Controlled Cohort Study

Background Resource utilization among emergency department (ED) patients with possible coronary chest pain is highly variable. Methods and Results Controlled cohort study amongst 21 EDs of an integrated healthcare system examining the implementation of a graded coronary risk stratification algorithm (RISTRA-ACS [risk stratification for acute coronary syndrome]). Thirteen EDs had access to RISTRA-ACS within the electronic health record (RISTRA sites) beginning in month 24 of a 48-month study period (January 2016 to December 2019); the remaining 8 EDs served as contemporaneous controls. Study participants had a chief complaint of chest pain and serum troponin measurement in the ED. The primary outcome was index visit resource utilization (observation unit or hospital admission, or 7-day objective cardiac testing). Secondary outcomes were 30-day objective cardiac testing, 60-day major adverse cardiac events (MACE), and 60-day MACE-CR (MACE excluding coronary revascularization). Difference-in-differences analyses controlled for secular trends with stratification by estimated risk and adjustment for risk factors, ED physician and facility. A total of 154 914 encounters were included. Relative to control sites, 30-day objective cardiac testing decreased at RISTRA sites among patients with low (≤2%) estimated 60-day MACE risk (-2.5%, 95% CI -3.7 to -1.2%, P<0.001) and increased among patients with non-low (>2%) estimated risk (+2.8%, 95% CI +0.6 to +4.9%, P=0.014), without significant overall change (-1.0%, 95% CI -2.1 to 0.1%, P=0.079). There were no statistically significant differences in index visit resource utilization, 60-day MACE or 60-day MACE-CR. Conclusions Implementation of RISTRA-ACS was associated with better allocation of 30-day objective cardiac testing and no change in index visit resource utilization or 60-day MACE. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03286179.

Clinical characteristics of COVID-19 patients evaluated in the emergency department: A retrospective cohort study of 801 cases

BACKGROUND

Coronavirus disease 2019 (COVID-19), the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has extracted devastating tolls. Despite its pervasiveness, robust information on disease characteristics in the emergency department (ED) and how that information predicts clinical course remain limited.

METHODS

We conducted a retrospective cohort study of the first ED visit from SARS-CoV-2-positive patients in our health system, from February 21, 2020 to April 5, 2020. We reviewed each patient's ED visit(s) and included the first visit with symptoms consistent with COVID-19. We collected demographic, clinical, and treatment variables from electronic health records and structured manual chart review. We used multivariable logistic regression to examine the association between patient characteristics and 2 primary outcomes: a critical outcome and hospitalization from index visit. Our critical outcome was defined as death or advanced respiratory support (high flow nasal cannula or greater) within 21 days.

RESULTS

Of the first 1030 encounters, 801 met our inclusion criteria: 15% were over age 75 years, 47% were female, and 24% were non-Hispanic white. We found 161 (20%) had a critical outcome and 393 (49%) were hospitalized. Independent predictors of a critical outcome included a history of hypertension, abnormal chest x-ray, elevated neutrophil to lymphocyte ratio, elevated blood urea nitrogen (BUN), measured fever, and abnormal respiratory vital signs (respiratory rate, oxygen saturation). Independent predictors of hospitalization included abnormal pulmonary auscultation, elevated BUN, measured fever, and abnormal respiratory vital signs.

CONCLUSIONS

In this large, diverse study of ED patients with COVID-19, we have identified numerous clinical characteristics that have independent associations with critical illness and hospitalization.

Outcomes among acute heart failure emergency department patients by preserved vs. reduced ejection fraction

Aims

This study aimed to assess short‐term outcomes among emergency department (ED) patients with acute heart failure (AHF) by preserved (≥50%) vs. reduced (<50%) ejection fraction (EF).

Methods and results

We conducted a retrospective, multicentre study of adult ED patients with AHF from 2017 to 2018 in an integrated healthcare system with 21 hospitals. Among patients with known EF, our primary outcome was 30 day all‐cause mortality, comparing patients with heart failure with preserved EF (HFpEF) and heart failure with reduced EF (HFrEF), adjusted for known risk factors. We ran separate multivariate regression models to compare 30 day mortality between HFpEF and HFrEF patients stratified by ED disposition (admit, observe, and discharge). Our secondary outcomes were adjusted 30 day all‐cause return hospital admission and rates of non‐fatal serious adverse events, including new intra‐aorta balloon pump, endotracheal intubation, renal failure requiring dialysis, myocardial infarction, or coronary revascularization. We conducted a sensitivity analysis among patients with EF ≤ 40% and compared our primary and secondary outcomes among patients with EF ≤ 40% with those with EF ≥ 50%. Among the 26 050 total ED encounters for AHF, 15 275 (58.6%) had known EF and 62.4% had HFpEF. The mean age was 76, 49.6% were women, and 60.5% were white. We found that 62.4% of patients were admitted, 18.3% were observed, and 19.3% were discharged from the ED. The 30 day all‐cause mortality rate was lowest among discharged patients (3.9%), intermediate among observed patients (5.9%), and highest among admitted patients (13.9%). Overall, the adjusted 30 day mortality rate was significantly higher among HFpEF patients compared with HFrEF patients (10.2% vs. 8.4%, P = 0.0004). HFpEF patients had higher mortality regardless of ED disposition, although the difference was only significant among admitted patients. The adjusted 30 day return hospital admission rates were not significantly different between HFpEF and HFrEF patients (17.9% vs. 17.8%, P = 0.89). The adjusted 30 day non‐fatal serious adverse event rates were significantly higher among HFrEF patients compared with HFpEF patients (13.7% vs. 11.1%, P < 0.0001), driven by myocardial infarction and coronary revascularization. We found that 3692 patients had EF ≤ 40%. Patients with EF ≥ 50% had significantly higher adjusted 30 day mortality rates compared with those with EF ≤ 40% (10.2% vs. 8.4%, P < 0.05).

Conclusion

In a contemporary population, almost three quarters of ED patients with AHF and known EF have HFpEF. These patients have higher 30 day adjusted mortality compared with those with HFrEF. Further studies might evaluate the underlying factors associated with this difference and target interventions to improve outcomes.

Prospective Validation and Comparative Analysis of Coronary Risk Stratification Strategies Among Emergency Department Patients With Chest Pain

Background

Coronary risk stratification is recommended for emergency department patients with chest pain. Many protocols are designed as “rule‐out” binary classification strategies, while others use graded‐risk stratification. The comparative performance of competing approaches at varying levels of risk tolerance has not been widely reported.

Methods and Results

This is a prospective cohort study of adult patients with chest pain presenting between January 2018 and December 2019 to 13 medical center emergency departments within an integrated healthcare delivery system. Using an electronic clinical decision support interface, we externally validated and assessed the net benefit (at varying risk thresholds) of several coronary risk scores (History, ECG, Age, Risk Factors, and Troponin [HEART] score, HEART pathway, Emergency Department Assessment of Chest Pain Score Accelerated Diagnostic Protocol), troponin‐only strategies (fourth‐generation assay), unstructured physician gestalt, and a novel risk algorithm (RISTRA‐ACS). The primary outcome was 60‐day major adverse cardiac event defined as myocardial infarction, cardiac arrest, cardiogenic shock, coronary revascularization, or all‐cause mortality. There were 13 192 patient encounters included with a 60‐day major adverse cardiac event incidence of 3.7%. RISTRA‐ACS and HEART pathway had the lowest negative likelihood ratios (0.06, 95% CI, 0.03–0.10 and 0.07, 95% CI, 0.04–0.11, respectively) and the greatest net benefit across a range of low‐risk thresholds. RISTRA‐ACS demonstrated the highest discrimination for 60‐day major adverse cardiac event (area under the receiver operating characteristic curve 0.92, 95% CI, 0.91–0.94, P<0.0001).

Conclusions

RISTRA‐ACS and HEART pathway were the optimal rule‐out approaches, while RISTRA‐ACS was the best‐performing graded‐risk approach. RISTRA‐ACS offers promise as a versatile single approach to emergency department coronary risk stratification.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03286179.

Predictors of Acute Atrial Fibrillation and Flutter Hospitalization across 7 U.S. Emergency Departments: A Prospective Study

INTRODUCTION

International rates of hospitalization for atrial fibrillation and flutter (AFF) from the emergency department (ED) vary widely without clear evidence to guide the identification of high-risk patients requiring inpatient management. We sought to determine (1) variation in hospital admission and (2) modifiable factors associated with hospitalization of AFF patients within a U.S. integrated health system.

METHODS

This multicenter prospective observational study of health plan members with symptomatic AFF was conducted using convenience sampling in 7 urban community EDs from 05/2011 to 08/2012. Prospective data collection included presenting symptoms, characteristics of atrial dysrhythmia, ED physician impression of hemodynamic instability, comorbid diagnoses, ED management, and ED discharge rhythm. All centers had full-time on-call cardiology consultation available. Additional variables were extracted from the electronic health record. We identified factors associated with hospitalization and included predictors in a multivariate Poisson Generalized Estimating Equations regression model to estimate adjusted relative risks while accounting for clustering by physician.

RESULTS

Among 1,942 eligible AFF patients, 1,074 (55.3%) were discharged home and 868 (44.7%) were hospitalized. Hospitalization rates ranged from 37.4% to 60.4% across medical centers. After adjustment, modifiable factors associated with increased hospital admission from the ED included non-sinus rhythm at ED discharge, no attempted cardioversion, and heart rate reduction.

DISCUSSION

Within an integrated health system, we found significant variation in AFF hospitalization rates and identified several modifiable factors associated with hospital admission. Standardizing treatment goals that specifically address best practices for ED rate reduction and rhythm control may reduce hospitalizations.

Use of Machine Learning to Develop a Risk-Stratification Tool for Emergency Department Patients With Acute Heart Failure

STUDY OBJECTIVE

We use variables from a recently derived acute heart failure risk-stratification rule (STRATIFY) as a basis to develop and optimize risk prediction using additional patient clinical data from electronic health records and machine-learning models.

METHODS

Using a retrospective cohort design, we identified all emergency department (ED) visits for acute heart failure between January 1, 2017, and December 31, 2018, among adult health plan members of a large system with 21 EDs. The primary outcome was any 30-day serious adverse event, including death, cardiopulmonary resuscitation, balloon-pump insertion, intubation, new dialysis, myocardial infarction, or coronary revascularization. Starting with the 13 variables from the STRATIFY rule (base model), we tested whether predictive accuracy in a different population could be enhanced with additional electronic health record-based variables or machine-learning approaches (compared with logistic regression). We calculated our derived model area under the curve (AUC), calculated test characteristics, and assessed admission rates across risk categories.

RESULTS

Among 26,189 total ED encounters, mean patient age was 74 years, 51.7% were women, and 60.7% were white. The overall 30-day serious adverse event rate was 18.8%. The base model had an AUC of 0.76 (95% confidence interval 0.74 to 0.77). Incorporating additional variables led to improved accuracy with logistic regression (AUC 0.80; 95% confidence interval 0.79 to 0.82) and machine learning (AUC 0.85; 95% confidence interval 0.83 to 0.86). We found that 11.1%, 25.7%, and 48.9% of the study population had predicted serious adverse event risk of less than or equal to 3%, less than or equal to 5%, and less than or equal to 10%, respectively, and 28% of those with less than or equal to 3% risk were admitted.

CONCLUSION

Use of a machine-learning model with additional variables improved 30-day risk prediction compared with conventional approaches.

Automated Retrospective Calculation of the EDACS and HEART Scores in a Multicenter Prospective Cohort of Emergency Department Chest Pain Patients

OBJECTIVES

Coronary risk scores are commonly applied to emergency department patients with undifferentiated chest pain. Two prominent risk score-based protocols are the Emergency Department Assessment of Chest pain Score Accelerated Diagnostic Protocol (EDACS-ADP) and the History, ECG, Age, Risk factors, and Troponin (HEART) pathway. Since prospective documentation of these risk determinations can be challenging to obtain, quality improvement projects could benefit from automated retrospective risk score classification methodologies.

METHODS

EDACS-ADP and HEART pathway data elements were prospectively collected using a Web-based electronic clinical decision support (eCDS) tool over a 24-month period (2018-2019) among patients presenting with chest pain to 13 EDs within an integrated health system. Data elements were also extracted and processed electronically (retrospectively) from the electronic health record (EHR) for the same patients. The primary outcome was agreement between the prospective/eCDS and retrospective/EHR data sets on dichotomous risk protocol classification, as assessed by kappa statistics (ĸ).

RESULTS

There were 12,110 eligible eCDS uses during the study period, of which 66 and 47% were low-risk encounters by EDACS-ADP and HEART pathway, respectively. Agreement on low-risk status was acceptable for EDACS-ADP (ĸ = 0.73, 95% confidence interval [CI] = 0.72 to 0.75) and HEART pathway (ĸ = 0.69, 95% CI = 0.68 to 0.70) and for the continuous scores (interclass correlation coefficients = 0.87 and 0.84 for EDACS and HEART, respectively).

CONCLUSIONS

Automated retrospective determination of low risk status by either the EDACS-ADP or the HEART pathway provides acceptable agreement compared to prospective score calculations, providing a feasible risk adjustment option for use in large data set analyses.

Diagnostic Performance of Emergency Physician Gestalt for Predicting Acute Appendicitis in Patients Age 5 to 20 Years

OBJECTIVES

Pediatric appendicitis remains a challenging diagnosis in the emergency department (ED). Available risk prediction algorithms may contribute to excessive ED imaging studies. Incorporation of physician gestalt assessment could help refine predictive tools and improve diagnostic imaging decisions.

METHODS

This study was a subanalysis of a parent study that prospectively enrolled patients ages 5 to 20.9 years with a chief complaint of abdominal pain presenting to 11 community EDs within an integrated delivery system between October 1, 2016, and September 30, 2018. Prior to diagnostic imaging, attending emergency physicians enrolled patients with ≤5 days of right-sided or diffuse abdominal pain using a Web-based application embedded in the electronic health record. Predicted risk (gestalt) of acute appendicitis was prospectively entered using a sliding scale from 1% to 100%. As a planned secondary analysis, we assessed the performance of gestalt via c-statistics of receiver operating characteristic (ROC) curves; tested associations between gestalt performance and patient, physician, and facility characteristics; and examined clinical characteristics affecting gestalt estimates.

RESULTS

Of 3,426 patients, 334 (9.8%) had confirmed appendicitis. Physician gestalt had excellent ROC curve characteristics (c-statistic = 0.83, 95% confidence interval = 0.81 to 0.85), performing particularly well in the low-risk strata (appendicitis rate = 1.1% in gestalt 1%-10% range, negative predictive value of 98.9% for appendicitis diagnosis). Physicians with ≥5 years since medical school graduation demonstrated improved gestalt performance over those with less experience (p = 0.007). All clinical characteristics tested, except pain <24 hours, were significantly associated with physician gestalt value (p < 0.05).

CONCLUSION

Physician gestalt for acute appendicitis diagnosis performed well, especially in low-risk patients and when employed by experienced physicians.

Hospitalization Is Less Common in Ambulatory Patients With Acute Pulmonary Embolism Diagnosed Before Emergency Department Referral Than After Arrival

BACKGROUND

Emergency department (ED) patients with acute pulmonary embolism (PE) may undergo diagnostic pulmonary imaging as an outpatient before referral to the ED for definitive management. This population has not been well characterized.

METHODS

This retrospective cohort study included ambulatory adults with acute objectively confirmed PE across 21 EDs in an integrated health care system from January 1, 2013, through April 30, 2015. We excluded patients arriving by ambulance. We compared outpatients with diagnostic pulmonary imaging in the 12 hours prior to ED arrival (the clinic-based cohort) with those receiving imaging for PE only after ED arrival. We reported adjusted odds ratio (aOR) with 95% confidence intervals (CIs) for hospitalization, adjusted for race, presyncope or syncope, proximal clot location, and PE Severity Index class.

RESULTS

Among 2,352 eligible ED patients with acute PE, 344 (14.6%) had a clinic-based diagnosis. This cohort had lower PE Severity Index classification and were less likely to be hospitalized than their counterparts with an ED-based diagnosis: 80.8% vs. 92.0% (p < 0.0001). The inverse association with hospitalization persisted after adjusting for the above patient characteristics with aOR of 0.36 (95% CI = 0.26 to 0.50).

CONCLUSION

In the study setting, ambulatory outpatients with acute PE are commonly diagnosed before ED arrival. A clinic-based diagnosis of PE identifies ED patients less likely to be hospitalized. Research is needed to identify which patients with a clinic-based PE diagnosis may not require transfer to the ED before home discharge.

Presyncope Is Associated with Intensive Care Unit Admission in Emergency Department Patients with Acute Pulmonary Embolism

Introduction

Syncope is common among emergency department (ED) patients with acute pulmonary embolism (PE) and indicates a higher acuity and worse prognosis than in patients without syncope. Whether presyncope carries the same prognostic implications has not been established. We compared incidence of intensive care unit (ICU) admission in three groups of ED PE patients: those with presyncope; syncope; and neither.

Methods

This retrospective cohort study included all adults with acute, objectively confirmed PE in 21 community EDs from January 2013–April 2015. We combined electronic health record extraction with manual chart abstraction. We used chi-square test for univariate comparisons and performed multivariate analysis to evaluate associations between presyncope or syncope and ICU admission from the ED, reported as adjusted odds ratios (aOR) with 95% confidence intervals (CI).

Results

Among 2996 PE patients, 82 (2.7%) had presyncope and 109 (3.6%) had syncope. ICU admission was similar between groups (presyncope 18.3% vs syncope 25.7%) and different than their non-syncope counterparts (either 22.5% vs neither 4.7%; p<0.0001). On multivariate analysis, both presyncope and syncope were independently associated with ICU admission, controlling for demographics, higher-risk PE Severity Index (PESI) class, ventilatory support, proximal clot location, and submassive and massive PE classification: presyncope, aOR 2.79 (95% CI, 1.40, 5.56); syncope, aOR 4.44 (95% CI 2.52, 7.80). These associations were only minimally affected when excluding massive PE from the model. There was no significant interaction between either syncope or presyncope and PESI, submassive or massive classification in predicting ICU admission.

Conclusion

Presyncope appears to carry similar strength of association with ICU admission as syncope in ED patients with acute PE. If this is confirmed, clinicians evaluating patients with acute PE may benefit from including presyncope in their calculus of risk assessment and site-of-care decision-making.

Validation of the Pediatric Appendicitis Risk Calculator (pARC) in a Community Emergency Department Setting

STUDY OBJECTIVE

The pediatric Appendicitis Risk Calculator (pARC) is a validated clinical tool for assessing a child's probability of appendicitis. Our objective was to assess the performance of the pARC in community emergency departments (EDs) and to compare its performance with that of the Pediatric Appendicitis Score (PAS).

METHODS

We conducted a prospective validation study from October 1, 2016, to April 30, 2018, in 11 community EDs serving general populations. Patients aged 5 to 20.9 years and with a chief complaint of abdominal pain and less than or equal to 5 days of right-sided or diffuse abdominal pain were eligible for study enrollment. Our primary outcome was the presence or absence of appendicitis within 7 days of the index visit. We reported performance characteristics and secondary outcomes by pARC risk strata and compared the receiver operator characteristic (ROC) curves of the PAS and pARC.

RESULTS

We enrolled 2,089 patients with a mean age of 12.4 years, 46% of whom were male patients. Appendicitis was confirmed in 353 patients (16.9%), of whom 55 (15.6%) had perforated appendixes. Fifty-four percent of patients had very low (<5%) or low (5% to 14%) predicted risk, 43% had intermediate risk (15% to 84%), and 4% had high risk (≥85%). In the very-low- and low-risk groups, 1.4% and 3.0% of patients had appendicitis, respectively. The area under the ROC curve was 0.89 (95% confidence interval 0.87 to 0.92) for the pARC compared with 0.80 (95% confidence interval 0.77 to 0.82) for the PAS.

CONCLUSION

The pARC accurately assessed appendicitis risk for children aged 5 years and older in community EDs and the pARC outperformed the PAS.

Discriminatory Value of the Ascending Aorta Diameter in Suspected Acute Type A Aortic Dissection

OBJECTIVE

The objective was to determine if ascending aorta (AscAo) diameters measured by noncontrast computed tomography (CT) allow for meaningful discrimination between patients with and without type A aortic dissection (TAAD), ideally with 100% sensitivity.

METHODS

This study was a retrospective analysis of cases of TAAD, as well as controls, undergoing evaluation for TAAD with CT aortography, presenting to 21 emergency departments within an integrated health system between 2007 and 2015. AscAo diameters were determined using axial noncontrast CT images at the level of the right main pulmonary artery by two readers. AscAo diameters were additionally normalized for age, sex, and body surface area (assessed by a Z-score, which is the number of standard deviations between the observed and expected AscAo diameters). Overall model discrimination was assessed using the area under the receiver operating characteristic curve (AUC). Comparative discrimination was assessed using both the change in AUC (∆AUC) and the continuous net reclassification index (NRI).

RESULTS

A total of 230 cases of TAAD and 325 controls were included in the study. The median ages for cases and controls were 65 and 62 years, and the median AscAo diameters were 50 and 35 mm, respectively. The raw and normalized AscAo diameters demonstrated similarly excellent discrimination (AUCs of 0.96 vs. 0.97, respectively; ∆AUC = 0.01, p = 0.09) and an NRI of 0.30 (95% confidence interval [CI] = 0.13-0.47), both indicating small incremental improvements in classification with the use of the normalized AscAo measures. A raw AscAo diameter of 34 mm and a normalized Z-score of 1.84 both yielded 100% sensitivity for TAAD, with respective specificities of 35% (95% CI = 29.6%-40.2%) and 67% (95% CI = 61.7%-72.2%).

CONCLUSIONS

Nearly all patients with TAAD appear to have enlarged AscAo diameters as measured by noncontrast CT, whereas most patients with suspected but absent TAAD have relatively normal AscAo diameters. Both raw and normalized AscAo measures provided relatively comparable discriminatory value. If validated, these data may be useful in adjudicating risk among patients with suspected TAAD in whom a criterion standard test is unavailable, nondiagnostic, or contraindicated.

Long-Term Outcomes Among Patients Discharged From the Hospital With Moderate Anemia: A Retrospective Cohort Study

BACKGROUND

Randomized clinical trial findings support decreased red blood cell (RBC) transfusion and short-term tolerance of in-hospital anemia. However, long-term outcomes related to changes in transfusion practice have not been described.

OBJECTIVE

To describe the prevalence of anemia at and after hospital discharge and associated morbidity and mortality events.

DESIGN

Retrospective cohort study.

SETTING

Integrated health care delivery system with 21 hospitals serving 4 million members.

PARTICIPANTS

445 371 surviving adults who had 801 261 hospitalizations between January 2010 and December 2014.

MEASUREMENTS

Hemoglobin levels and RBC transfusion, rehospitalization, and mortality events within 6 months of hospital discharge. Generalized estimating equations were used to examine trends over time, accounting for correlated observations and patient-level covariates.

RESULTS

From 2010 to 2014, the prevalence of moderate anemia (hemoglobin levels between 7 and 10 g/dL) at hospital discharge increased from 20% to 25% (P < 0.001) and RBC transfusion declined by 28% (39.8 to 28.5 RBC units per 1000 patients; P < 0.001). The proportion of patients whose moderate anemia had resolved within 6 months of hospital discharge decreased from 42% to 34% (P < 0.001), and RBC transfusion and rehospitalization within 6 months of hospital discharge decreased from 19% to 17% and 37% to 33%, respectively (P < 0.001 for both). During this period, the adjusted 6-month mortality rate decreased from 16.1% to 15.6% (P = 0.004) in patients with moderate anemia, in parallel with that of all others.

LIMITATION

Possible unmeasured confounding.

CONCLUSION

Anemia after hospitalization increased in parallel with decreased RBC transfusion. This increase was not accompanied by a rise in subsequent RBC use, rehospitalization, or mortality within 6 months of hospital discharge. Longitudinal analyses support the safety of practice recommendations to limit RBC transfusion and tolerate anemia during and after hospitalization.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute.

Increasing Safe Outpatient Management of Emergency Department Patients With Pulmonary Embolism: A Controlled Pragmatic Trial

BACKGROUND

Many low-risk patients with acute pulmonary embolism (PE) in the emergency department (ED) are eligible for outpatient care but are hospitalized nonetheless. One impediment to home discharge is the difficulty of identifying which patients can safely forgo hospitalization.

OBJECTIVE

To evaluate the effect of an integrated electronic clinical decision support system (CDSS) to facilitate risk stratification and decision making at the site of care for patients with acute PE.

DESIGN

Controlled pragmatic trial. (ClinicalTrials.gov: NCT03601676).

SETTING

All 21 community EDs of an integrated health care delivery system (Kaiser Permanente Northern California).

PATIENTS

Adult ED patients with acute PE.

INTERVENTION

Ten intervention sites selected by convenience received a multidimensional technology and education intervention at month 9 of a 16-month study period (January 2014 to April 2015); the remaining 11 sites served as concurrent controls.

MEASUREMENTS

The primary outcome was discharge to home from either the ED or a short-term (<24-hour) outpatient observation unit based in the ED. Adverse outcomes included return visits for PE-related symptoms within 5 days and recurrent venous thromboembolism, major hemorrhage, and all-cause mortality within 30 days. A difference-in-differences approach was used to compare pre-post changes at intervention versus control sites, with adjustment for demographic and clinical characteristics.

RESULTS

Among 881 eligible patients diagnosed with PE at intervention sites and 822 at control sites, adjusted home discharge increased at intervention sites (17.4% pre- to 28.0% postintervention) without a concurrent increase at control sites (15.1% pre- and 14.5% postintervention). The difference-in-differences comparison was 11.3 percentage points (95% CI, 3.0 to 19.5 percentage points; P = 0.007). No increases were seen in 5-day return visits related to PE or in 30-day major adverse outcomes associated with CDSS implementation.

LIMITATION

Lack of random allocation.

CONCLUSION

Implementation and structured promotion of a CDSS to aid physicians in site-of-care decision making for ED patients with acute PE safely increased outpatient management.

PRIMARY FUNDING SOURCE

Garfield Memorial National Research Fund and The Permanente Medical Group Delivery Science and Physician Researcher Programs.

Thromboprophylaxis for Patients with High-risk Atrial Fibrillation and Flutter Discharged from the Emergency Department

Introduction

Many patients with atrial fibrillation or atrial flutter (AF/FL) who are high risk for ischemic stroke are not receiving evidence-based thromboprophylaxis. We examined anticoagulant prescribing within 30 days of receiving dysrhythmia care for non-valvular AF/FL in the emergency department (ED).

Methods

This prospective study included non-anticoagulated adults at high risk for ischemic stroke (ATRIA score ≥7) who received emergency AF/FL care and were discharged home from seven community EDs between May 2011 and August 2012. We characterized oral anticoagulant prescribing patterns and identified predictors of receiving anticoagulants within 30 days of the index ED visit. We also describe documented reasons for withholding anticoagulation.

Results

Of 312 eligible patients, 128 (41.0%) were prescribed anticoagulation at ED discharge or within 30 days. Independent predictors of anticoagulation included age (adjusted odds ratio [aOR] 0.89 per year, 95% confidence interval [CI] 0.82–0.96); ED cardiology consultation (aOR 1.89, 95% CI [1.10–3.23]); and failure of sinus restoration by time of ED discharge (aOR 2.65, 95% CI [1.35–5.21]). Reasons for withholding anticoagulation at ED discharge were documented in 139 of 227 cases (61.2%), the most common of which were deferring the shared decision-making process to the patient’s outpatient provider, perceived bleeding risk, patient refusal, and restoration of sinus rhythm.

Conclusion

Approximately 40% of non-anticoagulated AF/FL patients at high risk for stroke who presented for emergency dysrhythmia care were prescribed anticoagulation within 30 days. Physicians were less likely to anticoagulate older patients and those with ED sinus restoration. Opportunities exist to improve rates of thromboprophylaxis in this high-risk population.

Short-Term Outcomes and Factors Associated With Adverse Events Among Adults Discharged From the Emergency Department After Treatment for Acute Heart Failure

BACKGROUND

Although 80% of patients with heart failure seen in the emergency department (ED) are admitted, less is known about short-term outcomes and demand for services among discharged patients.

METHODS AND RESULTS

We examined adult members of a large integrated delivery system who visited an ED for acute heart failure and were discharged from January 1, 2013, through September 30, 2014. The primary outcome was a composite of repeat ED visit, hospital admission, or death within 7 days of discharge. We identified multivariable baseline patient-, provider-, and facility-level factors associated with adverse outcomes within 7 days of ED discharge using logistic regression. Among 7614 patients, mean age was 77.2 years, 51.9% were women, and 28.4% were people of color. Within 7 days of discharge, 75% had outpatient follow-up (clinic, telephone, or e-mail), 7.1% had an ED revisit, 4.7% were hospitalized, and 1.2% died. Patients who met the primary outcome were more likely to be older, smokers, have a history of hemorrhagic stroke, hypothyroidism, and dementia, and less likely to be treated in a facility with an observation unit. In multivariable analysis, higher comorbidity scores and history of smoking were associated with a higher odds of the primary outcome, whereas treatment in a facility with an observation unit and presence of outpatient follow-up within 7 days were associated with a lower odds.

CONCLUSIONS

We identified selected hospital and patient characteristics associated with short-term adverse outcomes. Further understanding of these factors may optimize safe outpatient management in ED-treated patients with heart failure.

Outcomes Following Possible Undiagnosed Aneurysmal Subarachnoid Hemorrhage: A Contemporary Analysis

OBJECTIVES

Existing literature suggests that patients with aneurysmal subarachnoid hemorrhage (aSAH) and "sentinel" aSAH symptoms prompting healthcare evaluations prior to aSAH diagnosis are at increased risk of unfavorable neurologic outcomes and death. Accordingly, these encounters have been presumed to be unrecognized opportunities to diagnose aSAH and the worse outcomes representative of the added risks of delayed diagnoses. We sought to reinvestigate this paradigm among a contemporary cohort of patients with aSAH.

METHODS

A case-control cohort was retrospectively assembled among patients diagnosed with aSAH between January 1, 2007 and June 30, 2013 within an integrated healthcare delivery system. Patients with a discrete clinical evaluation for headache or neck pain within 14 days prior to formal aSAH diagnosis were identified as cases, and the remaining patients served as controls. Modified Rankin Scale scores at 90 days and 1 year were determined by structured chart review. Multivariable logistic regression controlling for age, sex, ethnicity, presence of intracerebral or intraventricular hemorrhage at diagnosis, and aneurysm size was used to compare adjusted outcomes. Sensitivity analyses were performed using varying definitions of favorable neurologic outcomes, a restricted control subgroup of patients with normal mental status at hospital admission, inclusion of additional cases that were diagnosed outside of the integrated health system, and exclusion of patients without evidence of subarachnoid blood on initial noncontrast cranial computed tomography (CT) at the diagnostic encounter (i.e. "CT-negative" SAH).

RESULTS

A total of 450 patients with aSAH were identified, 46 (10%) of whom had clinical evaluations for possible aSAH-related symptoms in the 14 days preceding formal diagnosis (cases). In contrast to prior reports, no differences were observed among cases compared to control patients in adjusted odds of death or unfavorable neurologic status at 90 days (0.35, 95% confidence interval [CI] = 0.11-1.15; 0.59, 95% CI = 0.22-1.60, respectively) or at 1 year (0.58, 95% CI = 0.19-1.73; 0.52, 95% CI = 0.18-1.51, respectively). Likewise, neither restricting the analysis to a control subgroup of patients with normal mental status at hospital admission, varying the dichotomous definition of unfavorable neurologic outcome, inclusion of cases diagnosed outside the integrated health system, or exclusion of patients with CT-negative SAH resulted in significant adjusted outcome differences.

CONCLUSION

In a contemporary cohort of patients with aSAH, we observed no statistically significant increase in the adjusted odds of death or unfavorable neurologic outcomes among patients with clinical evaluations for possible aSAH-related symptoms in the 14 days preceding formal diagnosis of aSAH. While these findings cannot exclude a smaller risk difference than previously reported, they can help refine decision analyses and testing threshold determinations for patients with possible aSAH.

Use of Traumatic Brain Injury Prediction Rules With Clinical Decision Support

OBJECTIVES

We determined whether implementing the Pediatric Emergency Care Applied Research Network (PECARN) traumatic brain injury (TBI) prediction rules and providing risks of clinically important TBIs (ciTBIs) with computerized clinical decision support (CDS) reduces computed tomography (CT) use for children with minor head trauma.

METHODS

Nonrandomized trial with concurrent controls at 5 pediatric emergency departments (PEDs) and 8 general EDs (GEDs) between November 2011 and June 2014. Patients were <18 years old with minor blunt head trauma. Intervention sites received CDS with CT recommendations and risks of ciTBI, both for patients at very low risk of ciTBI (no Pediatric Emergency Care Applied Research Network rule factors) and those not at very low risk. The primary outcome was the rate of CT, analyzed by site, controlling for time trend.

RESULTS

We analyzed 16 635 intervention and 2394 control patients. Adjusted for time trends, CT rates decreased significantly (P < .05) but modestly (2.3%-3.7%) at 2 of 4 intervention PEDs for children at very low risk. The other 2 PEDs had small (0.8%-1.5%) nonsignificant decreases. CT rates did not decrease consistently at the intervention GEDs, with low baseline CT rates (2.1%-4.0%) in those at very low risk. The control PED had little change in CT use in similar children (from 1.6% to 2.9%); the control GED showed a decrease in the CT rate (from 7.1% to 2.6%). For all children with minor head trauma, intervention sites had small decreases in CT rates (1.7%-6.2%).

CONCLUSIONS

The implementation of TBI prediction rules and provision of risks of ciTBIs by using CDS was associated with modest, safe, but variable decreases in CT use. However, some secular trends were also noted.

Optimizing Clinical Decision Support in the Electronic Health Record. Clinical Characteristics Associated with the Use of a Decision Tool for Disposition of ED Patients with Pulmonary Embolism

OBJECTIVE

Adoption of clinical decision support (CDS) tools by clinicians is often limited by workflow barriers. We sought to assess characteristics associated with clinician use of an electronic health record-embedded clinical decision support system (CDSS).

METHODS

In a prospective study on emergency department (ED) activation of a CDSS tool across 14 hospitals between 9/1/14 to 4/30/15, the CDSS was deployed at 10 active sites with an on-site champion, education sessions, iterative feedback, and up to 3 gift cards/clinician as an incentive. The tool was also deployed at 4 passive sites that received only an introductory educational session. Activation of the CDSS - which calculated the Pulmonary Embolism Severity Index (PESI) score and provided guidance - and associated clinical data were collected prospectively. We used multivariable logistic regression with random effects at provider/facility levels to assess the association between activation of the CDSS tool and characteristics at: 1) patient level (PESI score), 2) provider level (demographics and clinical load at time of activation opportunity), and 3) facility level (active vs. passive site, facility ED volume, and ED acuity at time of activation opportunity).

RESULTS

Out of 662 eligible patient encounters, the CDSS was activated in 55%: active sites: 68% (346/512); passive sites 13% (20/150). In bivariate analysis, active sites had an increase in activation rates based on the number of prior gift cards the physician had received (96% if 3 prior cards versus 60% if 0, p<0.0001). At passive sites, physicians < age 40 had higher rates of activation (p=0.03). In multivariable analysis, active site status, low ED volume at the time of diagnosis and PESI scores I or II (compared to III or higher) were associated with higher likelihood of CDSS activation.

CONCLUSIONS

Performing on-site tool promotion significantly increased odds of CDSS activation. Optimizing CDSS adoption requires active education.

False-negative Interpretations of Cranial Computed Tomography in Aneurysmal Subarachnoid Hemorrhage

OBJECTIVES

Prior studies examining the sensitivity of cranial computed tomography (CT) for the detection of subarachnoid hemorrhage (SAH) have used the final radiology report as the reference standard. However, optimal sensitivity may have been underestimated due to misinterpretation of reportedly normal cranial CTs. This study aims to estimate the incidence of missed CT evidence of SAH among a cohort of patients with aneurysmal SAH (aSAH).

METHODS

We performed a retrospective chart review of emergency department (ED) encounters within an integrated health delivery system between January 2007 and June 2013 to identify patients diagnosed with aSAH. All initial noncontrast CTs from aSAH cases diagnosed by lumbar puncture (LP) and angiography following a reportedly normal noncontrast cranial CT (CT-negative aSAH) were then reviewed in a blinded, independent fashion by two board-certified neuroradiologists to assess for missed evidence of SAH. Reviewers rated the CT studies as having definite evidence of SAH, probable evidence of SAH, or no evidence of SAH. Control patients who underwent a negative evaluation for aSAH based on cranial CT and LP results were also included at random in the imaging review cohort.

RESULTS

A total of 452 cases of aSAH were identified; 18 (4%) were cases of CT-negative aSAH. Of these, seven (39%) underwent cranial CT within 6 hours of headache onset, and two (11%) had their initial CTs formally interpreted by board-certified neuroradiologists. Blinded independent CT review revealed concordant agreement for either definite or probable evidence of SAH in nine of 18 (50%) cases overall and in five of the seven (71%) CTs performed within 6 hours of headache onset. Inter-rater agreement was 83% for definite SAH and 72% for either probable or definite SAH.

CONCLUSIONS

CT evidence of SAH was frequently present but unrecognized according to the final radiology report in cases of presumed CT-negative aSAH. This finding may help explain some of the discordance between prior studies examining the sensitivity of cranial CT for SAH.

Implementation of Computerized Physician Order Entry Is Associated With Increased Thrombolytic Administration for Emergency Department Patients With Acute Ischemic Stroke

STUDY OBJECTIVE

Electronic health record systems with computerized physician order entry and condition-specific order sets are intended to standardize patient management and minimize errors of omission. However, the effect of these systems on disease-specific process measures and patient outcomes is not well established. We seek to evaluate the effect of computerized physician order entry electronic health record implementation on process measures and short-term health outcomes for patients hospitalized with acute ischemic stroke.

METHODS

We conducted a quasi-experimental cohort study of patients hospitalized for acute ischemic stroke with concurrent controls that took advantage of the staggered implementation of a comprehensive computerized physician order entry electronic health record across 16 medical centers within an integrated health care delivery system from 2007 to 2012. The study population included all patients admitted to the hospital from the emergency department (ED) for acute ischemic stroke, with an initial neuroimaging study within 2.5 hours of ED arrival. We evaluated the association between the availability of a computerized physician order entry electronic health record and the rates of ED intravenous tissue plasminogen activator administration, hospital-acquired pneumonia, and inhospital and 90-day mortality, using doubly robust estimation models to adjust for demographics, comorbidities, secular trends, and concurrent primary stroke center certification status at each center.

RESULTS

Of 10,081 eligible patients, 6,686 (66.3%) were treated in centers after the computerized physician order entry electronic health record had been implemented. Computerized physician order entry was associated with significantly higher rates of intravenous tissue plasminogen activator administration (rate difference 3.4%; 95% confidence interval 0.8% to 6.0%) but not with significant rate differences in pneumonia or mortality.

CONCLUSION

For patients hospitalized for acute ischemic stroke, computerized physician order entry use was associated with increased use of intravenous tissue plasminogen activator.

Sensitivity of a Clinical Decision Rule and Early Computed Tomography in Aneurysmal Subarachnoid Hemorrhage

Introduction

Application of a clinical decision rule for subarachnoid hemorrhage, in combination with cranial computed tomography (CT) performed within six hours of ictus (early cranial CT), may be able to reasonably exclude a diagnosis of aneurysmal subarachnoid hemorrhage (aSAH). This study’s objective was to examine the sensitivity of both early cranial CT and a previously validated clinical decision rule among emergency department (ED) patients with aSAH and a normal mental status.

Methods

Patients were evaluated in the 21 EDs of an integrated health delivery system between January 2007 and June 2013. We identified by chart review a retrospective cohort of patients diagnosed with aSAH in the setting of a normal mental status and performance of early cranial CT. Variables comprising the SAH clinical decision rule (age ≥40, presence of neck pain or stiffness, headache onset with exertion, loss of consciousness at headache onset) were abstracted from the chart and assessed for inter-rater reliability.

Results

One hundred fifty-five patients with aSAH met study inclusion criteria. The sensitivity of early cranial CT was 95.5% (95% CI [90.9–98.2]). The sensitivity of the SAH clinical decision rule was also 95.5% (95% CI [90.9–98.2]). Since all false negative cases for each diagnostic modality were mutually independent, the combined use of both early cranial CT and the clinical decision rule improved sensitivity to 100% (95% CI [97.6–100.0]).

Conclusion

Neither early cranial CT nor the SAH clinical decision rule demonstrated ideal sensitivity for aSAH in this retrospective cohort. However, the combination of both strategies might optimize sensitivity for this life-threatening disease.

Timing of discharge follow-up for acute pulmonary embolism: retrospective cohort study

Introduction

Historically, emergency department (ED) patients with pulmonary embolism (PE) have been admitted for several days of inpatient care. Growing evidence suggests that selected ED patients with PE can be safely discharged home after a short length of stay. However, the optimal timing of follow up is unknown. We hypothesized that higher-risk patients with short length of stay (<24 hours from ED registration) would more commonly receive expedited follow up (≤3 days).

Methods

This retrospective cohort study included adults treated for acute PE in six community EDs. We ascertained the PE Severity Index risk class (for 30-day mortality), facility length of stay, the first follow-up clinician encounter, unscheduled return ED visits ≤3 days, 5-day PE-related readmissions, and 30-day all-cause mortality. Stratifying by risk class, we used multivariable analysis to examine age- and sex-adjusted associations between length of stay and expedited follow up.

Results

The mean age of our 175 patients was 63.2 (±16.8) years. Overall, 93.1% (n=163) of our cohort received follow up within one week of discharge. Fifty-six patients (32.0%) were sent home within 24 hours and 100 (57.1%) received expedited follow up, often by telephone (67/100). The short and longer length-of-stay groups were comparable in age and sex, but differed in rates of low-risk status (63% vs 37%; p<0.01) and expedited follow up (70% vs 51%; p=0.03). After adjustment, we found that short length of stay was independently associated with expedited follow up in higher-risk patients (adjusted odds ratio [aOR] 3.5; 95% CI [1.0–11.8]; p=0.04), but not in low-risk patients (aOR 2.2; 95% CI [0.8–5.7]; p=0.11). Adverse outcomes were uncommon (<2%) and were not significantly different between the two length-of-stay groups.

Conclusion

Higher-risk patients with acute PE and short length of stay more commonly received expedited follow up in our community setting than other groups of patients. These practice patterns are associated with low rates of 30-day adverse events.