York University Emergency Department Algorithm Research Articles

Concordance in Medical Urgency Classification of Discharge Diagnoses and Reasons for Visit

Current policies to divert emergency department (ED) visits for less medically urgent conditions to more cost-effective settings rely on retrospective adjudication of discharge diagnoses. However, patients present to the ED with concerns, making it challenging for clinicians. To characterize ED visits based on the medical urgency of the presenting reasons for visit and to explore the concordance between discharge diagnoses and reasons for visit. In this retrospective, cross-sectional study, a nationwide sample of ED visits by adults (aged ≥18 years) in the US from the 2018 and 2019 calendar years' ED data of the National Hospital Ambulatory Medical Care Survey was used. An algorithm to probabilistically assign ED visits into medical urgency categories based on the presenting reason for visit was developed. A 3-step, look-back method was applied using an updated version of the New York University ED algorithm, and a map of all possible discharge diagnoses to the same reasons for visit was developed. Analyses were conducted in July and August 2023. The main outcome was probabilistic medical urgency classification of reasons for visits and discharge diagnoses and their concordance. We analyzed 27 068 ED visits (mean age, 48.2% years [95% CI, 47.5%-48.9% years]) representing 190.7 million visits nationwide. Women (mean, 57.0% [95% CI, 55.9%-58.1%]) and patients with public health insurance coverage, including Medicare (mean, 24.9% [95% CI, 21.9%-28.0%]) and Medicaid (mean, 25.1% [95% CI, 21.0%-29.2%]), accounted for the largest share of ED visits, and a mean of 13.2% (95% CI, 11.4%-15.0%) of all visits resulted in a hospital admission. Overall, about 38.5% and 53.9% of all ED visits were classified with 100% and 75% probabilities, respectively, as injury related, emergency care needed, emergent but primary care treatable, nonemergent, or mental health or substance use disorders related based on discharge diagnosis compared with 0.4% and 12.4%, respectively, of all encounters based on patients' reason for visit. Among discharge diagnoses assigned with high certainty to only 1 urgency category using the New York University ED algorithm, between 38.0% (95% CI, 36.3%-39.6%) and 57.4% (95% CI, 56.0%-58.8%) aligned with the probabilistic categorical assignments of their corresponding reasons for visit. In this cross-sectional study of 190.7 million ED visits among adults aged 18 years or older, a smaller percentage of reasons for visit could be prospectively categorized with high accuracy to a specific medical urgency category compared with all visits based on discharge diagnoses, and a limited concordance between reasons for visit and discharge diagnoses was found. Alternative methods are needed to identify the medical necessity of ED encounters more accurately.

Association of the affordable care act with racial and ethnic disparities in uninsured emergency department utilization

BackgroundDisparities in uninsured emergency department (ED) use are well documented. However, a comprehensive analysis evaluating how the Affordable Care Act (ACA) may have reduced racial and ethnic disparities is lacking. The goal was to assess the association of the ACA with racial and ethnic disparities in uninsured ED use.MethodsThis study used data from the Healthcare Cost and Utilization Project (HCUP) State Emergency Department Databases (SEDD) for Georgia, Florida, Massachusetts, and New York from 2011 to 2017. Participants include non-elderly adults between 18 and 64 years old. Outcomes include uninsured rates of ED visits by racial and ethnic groups and stratified by medical urgency using the New York University ED algorithm. Visits were aggregated to year-quarter ED visits per 100,000 population and stratified for non-Hispanic White, non-Hispanic Black, and Hispanic non-elderly adults. Quasi-experimental difference-in-differences and triple differences regression analyses to identify the effect of the ACA and the separate effect of the Medicaid expansion were used comparing uninsured ED visits by race and ethnicity groups pre-post ACA.ResultsThe ACA was associated with a 14% reduction in the rate of uninsured ED visits per 100,000 population (from 10,258 pre-ACA to 8,877 ED visits per 100,000 population post-ACA) overall. The non-Hispanic Black compared to non-Hispanic White disparity decreased by 12.4% (-275.1 ED visits per 100,000) post-ACA. About 60% of the decline in the Black-White disparity was attributed to disproportionate declines in ED visit rates for conditions classified as not-emergent (-93.2 ED visits per 100,000), and primary care treatable/preventable (-64.1 ED visits per 100,000), while the disparity in ED visit rates for injuries and not preventable conditions also declined (-106.57 ED visits per 100,000). All reductions in disparities were driven by the Medicaid expansion. No significant decrease in Hispanic-White disparity was observed.ConclusionsThe ACA was associated with fewer uninsured ED visits and reduced the Black-White ED disparity, driven mostly by a reduction in less emergent ED visits after the ACA in Medicaid expansion states. Disparities between Hispanic and non-Hispanic White adults did not decline after the ACA. Despite the positive momentum of declining disparities in uninsured ED visits, disparities, especially among Black people, remain.

Geographic proximity to primary care providers as a risk-assessment criterion for quality performance measures.

Previous studies have found a mixed association between Patient-Centered Medical Home (PCMH) designation and improvements in primary care quality indicators, including avoidable pediatric emergency department (ED) encounters. Whether these associations persist after accounting for the geographic locations of providers relative to where patients reside is unknown. To examine the association between geographic proximity to primary care providers versus hospitals and risk of avoidable and potentially avoidable ED visits among children with pre-existing diagnosis of attention-deficit/hyperactivity disorder or asthma. Retrospective cohort study of a panel of pediatric Medicaid claims data from the South Carolina from 2016-2018 for 2,959 beneficiaries having a pre-existing diagnosis of attention-deficit/hyperactivity disorder (ADD, ages 6-12) and 6,390 beneficiaries with asthma (MMA, ages 5-18), as defined using Healthcare Effectiveness Data and Information Set (HEDIS) performance measures. We calculated differences in avoidable and potentially avoidable ED visits by the beneficiary's PCMH attribution type and in relation to differences in proximity to their primary care providers versus hospitals. Outcomes were defined using the New York University Emergency Department Algorithm (NYU-EDA). Differences in ED visit risk were assessed using generalized estimation equations and compared using marginal effects models. The 2.4 percentage point reduction in risk of avoidable ED visits among children in the ADD cohort who attended a PCMH versus those who did not increased to 3.9 to 7.2 percentage points as relative proximity to primary care providers versus hospitals improved (p < 0.01). Children in the ADD and MMA cohorts that were enrolled in a medical home, but did not attend one for primary care services exhibited a 5.4 and 3.0 percentage point increase in avoidable ED visit compared to children who were unenrolled and did not attend medical homes (p < 0.05), but these differences were only observed when geographic proximity to hospitals was more convenient than primary care providers. Mixed findings were observed for potentially avoidable visits. In several health care performance evaluations, patient-centered medical homes have not been found to reduce differences in hospital utilization for conditions that are treatable in primary care settings among children with chronic illnesses. Analytical approaches that also consider geographic proximity to health care services can identify performance benefits of medical homes. Expanding risk-adjustment models to also include geographic data would benefit ongoing quality improvement initiatives.

Association of Medicaid Expansion With Emergency Department Visits by Medical Urgency

Relatively little is known about the association of the Medicaid eligibility expansion under the Patient Protection and Affordable Care Act with emergency department (ED) visits categorized by medical urgency. To estimate the association between state Medicaid expansions and ED visits by the urgency of presenting conditions. This cross-sectional study used the Healthcare Cost and Utilization Project State Emergency Department Databases from January 2011 to December 2017 for 2 states that expanded Medicaid in 2014 (New York and Massachusetts) and 2 states that did not (Florida and Georgia). Difference-in-differences regression models were used to estimate the changes in ED visits overall and further stratified by the urgency of the conditions using an updated version of the New York University ED algorithm between the states that expanded Medicaid and those that did not, before and after the expansion. Data were analyzed between June 7 and December 12, 2021. State-level Medicaid eligibility expansion. Emergency department visits per 1000 population overall and stratified by medical urgency of the conditions. In total, 80.6 million ED visits by 26.0 million individuals were analyzed. Emergency department visits were concentrated among women (59.3%), non-Hispanic Black individuals (28.3%), non-Hispanic White individuals (47.8%), and those aged 18 to 34 years (47.5%) and 35 to 44 years (20.4%). The rates of ED visits increased by a mean of 2.4 visits in nonexpansion states and decreased by a mean of 2.2 visits in expansion states after 2014, resulting in a significant regression-adjusted decrease of 4.7 visits per 1000 population (95% CI, -7.7 to -1.5; P = .003) in expansion states. Most of this decrease was associated with decreases in ED visits by conditions classified as not emergent (-1.5 visits; 95% CI, -2.4 to -0.7; P < .001), primary care treatable (-1.1 visits; 95% CI, -1.6 to -0.5; P < .001), and potentially preventable (-0.3 visits; 95% CI, -0.5 to -0.1; P = .02). No significant changes were observed for ED visits related to injuries and conditions classified as not preventable (-1.4; 95% CI, -3.1 to 0.3; P = .10), as well as for substance use and mental health disorders (0.0; 95% CI, -0.2 to 0.2; P = .94). The findings of this study suggest that Medicaid expansion was associated with decreases in ED visits, for which decreases in ED visits for less medically emergent ED conditions may have been a factor.

Evaluating the utility of rule OP-35 to define preventability of ED visits for oncology patients at an academic cancer center.

272 Background: Rule OP-35, which characterizes treatment-related complications of patients receiving outpatient chemotherapy that result in a potentially avoidable emergency department (ED) visit or hospitalization, was developed to encourage practices to build treatment models that reduce such events. However, defining visits as potentially avoidable based on symptoms may not capture the complexity of caring for oncology patients. We aim to evaluate the effectiveness of OP-35 in identifying preventable ED visits by real world standards at an academic institution. Methods: A retrospective analysis was performed reviewing ED visits at the Sidney Kimmel Cancer Center (SKCC) at Thomas Jefferson University for oncology patients from 10/1/2020 to 1/31/2021. Each patient received care at SKCC had received intravenous or oral chemotherapy in the preceding 30 days, and each encounter was classified as potentially avoidable by OP-35 criteria. Two investigators independently conducted chart reviews to determine whether these visits were potentially avoidable, recording whether the patient attempted to contact their care team prior to the ED encounter and assessing if the concern could have been managed in a timely manner in an outpatient setting. The two records were then compared, and the principal investigator served as an arbiter for determining if a visit was potentially avoidable in instances where the investigators disagreed. Results: We reviewed 144 total encounters and excluded events from patients with either acute leukemia or breast cancer on hormone therapy only, leaving 107 encounters for analysis. After evaluating the clinical circumstances, we determined that 29% of these ED encounters were potentially avoidable. Applying New York University Emergency Department Algorithm (NYU-EDA) criteria, 69% of encounters were considered potentially avoidable. Patients called for advice before seeking ED care in 53% of unavoidable encounters compared to 26% of potentially avoidable encounters. An additional 14% of visits deemed unavoidable were from patients sent directly from clinic. For potentially avoidable encounters, 60% of patients were discharged directly from the ED. In comparison, 8% of unavoidable encounters led to discharge from the ED. Pain was the most common reason for encounters and 53% of these visits were considered potentially avoidable. Conclusions: We found that approximately 30% of ED encounters deemed avoidable by OP-35 criteria were considered potentially avoidable following clinician review. In the majority of cases patients were referred to the ED following initial outpatient attempts at management. NYU-EDA criteria for preventability did not correlate with OP-35 nor clinician consensus regarding potentially avoidable encounters. More work remains in refining tools to identify potentially avoidable ED visits for oncology patients.

High incidence of potentially preventable emergency department visits after major elective colorectal surgery.

Emergency department (ED) visits after surgery represent a significant cost burden on the healthcare system. Furthermore, many ED visits are related to issues of healthcare delivery services and may be avoidable. Few studies have assessed the reasons for ED visits after colorectal surgery. The main objectives of this study were to: (1) identify the reasons why patients presented to the ED within 30 postoperative days and (2) determine if these visits were potentially preventable. A retrospective chart review was conducted on elective major colorectal surgery cases performed in a single center between 01/2017 and 07/2019. Data collected included demographics, medical history, intraoperative details, postoperative complications, ED visits within 30 postoperative days, and readmissions. Each ED visit was assessed by two reviewers and graded on a scale adapted from the New York University ED algorithm. The gradings were: (1) non-emergent, (2) emergent but treatable in an ambulatory setting, (3) emergent/ED-care required but preventable if timely outpatient care was available, and (4) emergent/ED-care required and non-preventable. Grades 1-3 were deemed potentially preventable. Logistic regression identified independent predictors of potentially preventable visits. Six hundred and twenty five patients were included in the final analysis. 110 (17.6%) patients presented to the ED within 30days. The most common cause of ED visit were ileus/small bowel obstruction (SBO) (16.4%), superficial wound infection (15.5%), genitourinary issues (10.9%), and non-infectious gastrointestinal issues (nausea, malnutrition, diarrhea, high output stomas) (10.9%). After review, 51.8% of visits were considered potentially preventable (Grade 1-3). The most common causes of preventable ED visits were superficial wound infection (24.6%), non-infectious gastrointestinal issues (19.3%), and minor bleeding (14.0%). Creation of a new stoma was the only independent risk factor for potentially preventable ED visits (OR 2.14, 95%CI 1.03-4.47). Approximately half of ED visits within 30days of discharge were potentially preventable. These findings indicate a need to improve access to outpatient care to reduce preventable ED visits after elective colorectal surgery.

NYU-EDA in modelling the effect of COVID-19 on patient volumes in a Finnish emergency department

BackgroundEmergency departments (EDs) worldwide have been in the epicentre of the novel coronavirus disease (COVID-19). However, the impact of the pandemic and national emergency measures on the number of non-COVID-19 presentations and the assessed acuity of those presentations remain uncertain.MethodsWe acquired a retrospective cohort containing all ED visits in a Finnish secondary care hospital during years 2018, 2019 and 2020. We compared the number of presentations in 2020 during the national state of emergency, i.e. from March 16 to June 11, with numbers from 2018 and 2019. Presentations were stratified using localized New York University Emergency Department Algorithm (NYU-EDA) to evaluate changes in presentations with different acuity levels.ResultsA total of 27,526 presentations were observed. Compared to previous two years, total daily presentations were reduced by 23% (from 113 to 87, p < .001). In NYU-EDA classes, Non-Emergent visits were reduced the most by 42% (from 18 to 10, p < .001). Emergent presentations were reduced by 19 to 28% depending on the subgroup (p < .001). Number of injuries were reduced by 25% (from 27 to 20, p < .001). The NYU-EDA distribution changed statistically significantly with 4% point reduction in Non-Emergent visits (from 16 to 12%, p < .001) and 0.9% point increase in Alcohol-related visits (from 1.6 to 2.5%, p < .001).ConclusionsWe observed a significant reduction in total ED visits in the course of national state of emergency. Presentations were reduced in most of the NYU-EDA groups irrespective of the assessed acuity. A compensatory increase in presentations was not observed in the course of the 3 month lockdown. This implies either reduction in overall morbidity caused by decreased societal activity or widespread unwillingness to seek required medical advice.

Pathways to reduced emergency department and urgent care center use: Lessons from the comprehensive primary care initiative.

To determine the association between a large-scale, multi-payer primary care redesign-the Comprehensive Primary Care (CPC) Initiative-on outpatient emergency department (ED) and urgent care center (UCC) use and to identify the types of visits that drive the overall trends observed. Medicare claims data capturing characteristics and outcomes of 565674 Medicare fee-for-service (FFS) beneficiaries attributed to 497 CPC practices and 1165284 beneficiaries attributed to 908 comparison practices. We used an adjusted difference-in-differences framework to test the association between CPC and beneficiaries' ED and UCC use from October 2012 through December 2016. Regression models controlled for baseline practice and patient characteristics and practice-level clustering of standard errors. Our key outcomes were all-cause and primary care substitutable (PC substitutable) outpatient ED and UCC visits, and potentially primary care preventable (PPC preventable) ED visits, categorized by the New York University Emergency Department Algorithm. We used a propensity score-matched comparison group of practices that were similar to CPC practices before CPC on multiple dimensions. Both groups of practices had similar growth in ED and UCC visits in the two-year period before CPC. Comprehensive Primary Care practices had 2% (P=.06) lower growth in all-cause ED visits than comparison practices. They had 3% (P=.02) lower growth in PC substitutable ED visits, driven by lower growth in weekday PC substitutable visits (4%, P=.002). There was 3% (P=.04) lower growth in PPC preventable ED visits with no weekday/nonweekday differential. As expected, our falsification test showed no difference in ED visits for injuries. UCC visits had 9% lower growth for both all-cause (P=.08) and PC substitutable visits (P=.07). Our results suggest that greater access to the practice and more effective primary care both contributed to the lower growth in ED and UCC visits during the initiative.

The Comprehensive Primary Care Initiative and Emergency Department and Urgent Care Center Use

Improved access to quality primary care is considered a key element in reducing unnecessary visits to emergency departments (EDs) and urgent care clinics (UCCs) and in reducing expenditures. The Comprehensive Primary Care (CPC) initiative tested large‐scale payment and delivery reform in 497 primary care practices in seven regions. Practices received enhanced payment, data feedback, and learning support to improve outcomes. In this study, we analyze the effect of CPC on ED and UCC visits October 2012‐December 2016. We expect the greatest changes to occur with those types of visits most amenable to improved primary care‐primary care substitutable visits (for conditions treatable in a primary care setting), and potentially primary care preventable ED visits (for conditions whose symptoms and exacerbations can be mitigated with effective primary care). We disaggregated visits by day of week to study whether changes were concentrated during regular business days (via increased same‐day/next‐day appointments and more responsiveness during weekdays by the care team) versus weekends and holidays. We expect access improvements to have greater effects on weekdays.We estimated CPC’s four‐year effects on Medicare fee‐for‐service (FFS) beneficiaries’ all‐cause and primary care substitutable (PCS) outpatient ED and UCC use and on potentially primary care preventable (PPCP) ED visits. To categorize visits, we adapted the commonly used claims‐based New York University Emergency Department Algorithm. We estimated difference‐in‐differences regressions comparing changes in outcomes between before CPC began (baseline) and the four years of CPC for attributed Medicare FFS beneficiaries in CPC practices, with changes over the same period for beneficiaries attributed to propensity‐score‐matched comparison practices. Regressions controlled for baseline practice, patient characteristics, and clustering.565,674 Medicare FFS beneficiaries attributed to 497 CPC practices, and 1,165,284 beneficiaries attributed to 908 similar comparison practices.CPC practices had 2 percent decreased growth in all‐cause ED visits, and 3 percent lower growth in both PCS (P = .02) and PPCP ED visits (P = .04), relative to comparison practices. Lower growth in weekday visits (4 percent, P = .002) drove the PCS ED results. UCC visits had 9 percent lower growth for both all‐cause (P = .08) and PCS (P = .07). As expected, there was no difference in ED visits for injuries—which is an excellent falsification test.CPC was associated with lower growth in outpatient ED and UCC visits, driven by reductions in weekday PCS visits (likely reflecting improved access to the practice), and PPCP ED visits (suggesting the importance of improved primary care more generally).Large‐scale initiatives to improve access to quality primary care, such as CPC, hold promise for reducing visits to EDs and UCCs. More research in understanding the contributions of specific care delivery changes, from same‐day appointments to improved health status of patients, primary care practice transformation, and the related response of attributed beneficiaries could help explain the differential impacts on visits by weekday versus nonweekday.Centers for Medicare and Medicaid Services.

A revised classification algorithm for assessing emergency department visit severity of populations.

Analyses of emergency department (ED) use require visit classification algorithms based on administrative data. Our objectives were to present an expanded and revised version of an existing algorithm and to use this tool to characterize patterns of ED use across US hospitals and within a large sample of health plan enrollees. Observational study using National Hospital Ambulatory Medical Care Survey ED public use files and hospital billing data for a health plan cohort. Our Johns Hopkins University (JHU) team classified many uncategorized diagnosis codes into existing New York University Emergency Department Algorithm (NYU-EDA) categories and added 3 severity levels to the injury category. We termed this new algorithm the NYU/JHU-EDA. We then compared visit distributions across these 2 algorithms and 2 other previous revised versions of the NYU-EDA using our 2 data sources. Applying the newly developed NYU/JHU-EDA, we classified 99% of visits. Based on our analyses, it is evident that an even greater number of US ED visits than categorized by the NYU-EDA are nonemergent. For the first time, we provide a more complete picture of the level of severity among patients treated for injuries within US hospital EDs, with about 86% of such visits being nonsevere. Also, both the original and updated classification tools suggest that, of the 38% of ED visits that are clinically emergent, the majority either do not require ED resources or could have been avoided with better primary care. The updated NYU/JHU-EDA taxonomy appears to offer cogent retrospective inferences about population-level ED utilization.

Association between Practice Participation in a Pediatric-focused Medical Home Learning Collaborative and Reduction of Preventable Emergency Department Visits by Publicly-insured Children in Massachusetts.

Introduction:This study evaluates the impact of practice participation in a pediatric patient-centered medical home learning collaborative on preventable emergency department (ED) visits among children in MassHealth (Massachusetts Medicaid/Children’s Health Insurance Program).Methods:Claims and enrollment data were extracted for child MassHealth members (aged 3–18) comprising 2 groups: members enrolled in a group of 13 child-serving practices that participated in an intensive, 29-month long patient-centered medical home learning collaborative (intervention group), and members enrolled in a group of 12 comparison practices with roughly similar panel size, type, and geographic location (comparison group). Preventable ED visits were identified using a modified version of the New York University ED algorithm. Two analyses were then conducted: (1) a repeat cross-sectional analysis among children enrolled in intervention or comparison group practices during baseline (first half of 2011) and follow-up (second half of 2013) periods; and (2) a longitudinal analysis among a subset of children enrolled for the full study period (2011–2013). Both analyses tested whether the effect of the intervention differed for children with versus without chronic conditions (effect modification).Results:Preventable ED visits declined from baseline to follow-up among children in both intervention and comparison practices. In the cross-sectional analysis, the decrease was the same in both practice groups, and for children with versus without chronic conditions. The longitudinal analysis shows a statistically significantly greater decrease among children with chronic conditions enrolled in the intervention practices (P = 0.02).Conclusion:Children with chronic conditions might receive the greatest benefit from receiving care in a medical home setting.

Characterising emergency centre encounters in Mbour, Senegal as emergent-emergency care, emergent-primary care or non-emergent.

IntroductionEmergency medicine is a relatively new specialty in Africa, with the first emergency medicine training programme only started in South Africa in 2004. Continued emergency centre development and preparedness relies on a better understanding of the quantity and category of emergency centre encounters within the various African regions.MethodsThis study was conducted over four, consecutive months in 2014 using a retrospective chart review, aimed to examine the types of visits made to one emergency centre at the Grande Mbour Hospital in Mbour, Senegal. The New York University Emergency Department Algorithm was used to classify emergency centre encounters. Each diagnosis included in this study was classified per the algorithm as non-emergent; emergent but primary care treatable; emergent with emergency centre care needed but avoidable/preventable; and emergent with emergency centre care needed and not avoidable/preventable. The algorithm also categorised diagnoses of injury, mental health problems, alcohol, or substance abuse.ResultsThis study included 1268 diagnoses from the emergency centre. The most common presentations in Mbour, Senegal were injuries, with 302 cases (33%), and from the category: emergent but primary care treatable, with 303 cases (33%). In total, 174 cases (19%) were classified as: non-emergent. While only 93 cases (10%) were considered: emergency care needed/preventable or avoidable, a substantial number (n = 218, 24%) were categorised as: emergent with emergency centre care needed and not avoidable/preventable.ConclusionThis study provides the first description of patients presenting for care in the emergency centre of Mbour’s hospital and demonstrates the wide range of illnesses and types of trauma that the emergency centre must accommodate while contending with the limited resources available in the area. Understanding the burden of disease will help prioritise resources appropriately.

The Role of Charity Care and Primary Care Physician Assignment on ED Use in Homeless Patients

ObjectiveHomeless patients are a vulnerable population with a higher incidence of using the emergency department (ED) for noncrisis care. Multiple charity programs target their outreach toward improving the health of homeless patients, but few data are available on the effectiveness of reducing ED recidivism. The aim of this study is to determine whether inappropriate ED use for nonemergency care may be reduced by providing charity insurance and assigning homeless patients to a primary care physician (PCP) in an outpatient clinic setting. MethodsA retrospective medical records review of homeless patients presenting to the ED and receiving treatment between July 2013 and June 2014 was completed. Appropriate vs inappropriate use of the ED was determined using the New York University ED Algorithm. The association between patients with charity care coverage, PCP assignment status, and appropriate vs inappropriate ED use was analyzed and compared. ResultsFollowing New York University ED Algorithm standards, 76% of all ED visits were deemed inappropriate with approximately 77% of homeless patients receiving charity care and 74% of patients with no insurance seeking noncrisis health care in the ED (P=.112). About 50% of inappropriate ED visits and 43.84% of appropriate ED visits occurred in patients with a PCP assignment (P=.019). ConclusionsBoth charity care homeless patients and those without insurance coverage tend to use the ED for noncrisis care resulting in high rates of inappropriate ED use. Simply providing charity care and/or PCP assignment does not seem to sufficiently reduce inappropriate ED use in homeless patients.

Travel distance and sociodemographic correlates of potentially avoidable emergency department visits in California, 2006-2010: an observational study.

IntroductionUse of the hospital emergency department (ED) for medical conditions not likely to require immediate treatment is a controversial topic. It has been faulted for ED overcrowding, increased expenditures, and decreased quality of care. On the other hand, such avoidable ED utilization may be a manifestation of barriers to primary care access.MethodsA random 10% subsample of all ED visits with unmasked variables, or approximately 7.2% of all ED visits in California between 2006 and 2010 are used in the analysis. Using panel data methods, we employ linear probability and fractional probit models with hospital fixed effects to analyze the associations between avoidable ED utilization in California and observable patient characteristics. We also test whether shorter estimated road distances to the hospital ED are correlated with non-urgent ED utilization, as defined by the New York University ED Algorithm. We then investigate whether proximity of a Federally Qualified Health Center (FQHC) is correlated with reductions in non-urgent ED utilization among Medicaid patients.ResultsWe find that relative to the reference group of adults aged 35–64, younger patients generally have higher scores for non-urgent conditions and lower scores for urgent conditions. However, elderly patients (≥65) use the ED for conditions more likely to be urgent. Relative to male and white patients, respectively, female patients and all identified racial and ethnic minorities use the ED for conditions more likely to be non-urgent. Patients with non-commercial insurance coverage also use the ED for conditions more likely to be non-urgent. Medicare and Medicaid patients who live closer to the hospital ED have higher probability scores for non-emergent visits. However, among Medicaid enrollees, those who live in zip codes with an FQHC within 0.5 mile of the zip code population centroid visit the ED for medical conditions less likely to be non-emergent.ConclusionsThese patterns of ED utilization point to potential barriers to care among historically vulnerable groups, observable even when using rough estimates of travel distances and avoidable ED utilization.Electronic supplementary materialThe online version of this article (doi:10.1186/s12939-015-0158-y) contains supplementary material, which is available to authorized users.

An Analysis of the New York University Emergency Department Algorithm’s Suitability for Use in Gauging Changes in ED Usage Patterns

The Emergency Department Algorithm (EDA) developed at New York University uses administrative discharge data to distill hundreds of International Classification of Diseases-9 codes for emergency department (ED) visits into 4 categories, making it attractive to researchers and policy makers. The EDA has been used to analyze patterns of ED visits in a wide variety of locations and populations. However, there are concerns regarding the validity and use of the EDA for research and policy. To explain the findings of previous EDA users that it appears to lack sensitivity in detecting changes in ED utilization patterns. Mathematical simulation was used to analyze and explain the performance of the EDA in detecting differences in utilization patterns across hypothetical ED populations. Sensitivity analysis was used to illustrate the magnitude of changes in EDA outputs relative to changes in ED populations using a national sample of actual ED patients. The vast majority of possible EDA outputs are clustered so tightly as to show no significant change in outputs between different hypothetical populations. Sensitivity analysis shows that changes in EDA outputs are not nearly as great as the magnitude of the input differences across real-world populations. The EDA categorizes a very large variety of ED visits into a relatively small group of outputs. Its operating characteristics suggest that the EDA is insufficiently sensitive to changes in ED utilization patterns to be useful in assessing interventions to change them. This finding should caution potential users to consider the EDA's limitations before using it.

Emergency Room Use and Access to Primary Care: Evidence from Houston, Texas

To cope with the rising number of uninsured, communities around the country are pursuing a variety of strategies to expand local health care safety nets. One measure that has been suggested to evaluate what is working is primary care-related emergency department (ED) visits. In this paper, we evaluate the applicability of this measure as an access indicator by examining its correlation with other indicators of medical under-service. We obtained ED visit data from safety net hospitals in Houston, Texas and applied the New York University ED Algorithm to estimate the rate of visits that were primary care-related. We then examined at the ZIP code level the correlation of primary care-related ED visits per 1,000 population with the federal government's Index of Medical Underservice (IMU), the poverty rate, and the uninsurance rate. Primary care-related ED visits were found to be weakly correlated with the IMU and strongly correlated with the rate of uninsurance and poverty. These findings suggest that the combination of this indicator with other measures of access could be used to monitor and evaluate local initiatives designed to expand care and coverage to the medically underserved.