Increasing utilization of emergency department neuroimaging in Medicare beneficiaries from 1994 to 2015

Trends in non-focal neurological chief complaints and CT angiography utilization among adults in the emergency department

Prudent imaging use is essential for cost reduction and efficient patient triage. Recent efforts have focused on head and neck CTA in patients with emergent concerns for non-focal neurological complaints, but have failed to demonstrate whether increases in utilization have resulted in better care. The objective of this study was to examine trends in head and neck CTA ordering and determine whether a correlation exists between imaging utilization and positivity rates. This is a single-center retrospective observational study at a quaternary referral center. This study includes patients presenting with headache and/or dizziness to the emergency department between January 2017 and December 2021. Patients who received a head and neck CTA were compared to those who did not. The main outcomes included annual head and neck CTA utilization and positivity rates, defined as the percent of scans with attributable acute pathologies. Among 24,892 emergency department visits, 2264 (9.1%) underwent head and neck CTA imaging. The percentage of patients who received a scan over the study period increased from 7.89% (422/5351) in 2017 to 13.24% (662/5001) in 2021, representing a 67.4% increase from baseline (OR, 1.14; 95% CI 1.11-1.18; P < .001). The positivity rate, or the percentage of scans ordered that revealed attributable acute pathology, dropped from 16.8% (71/422) in 2017 to 10.4% (69/662) in 2021 (OR, 0.86; 95% CI 0.79-0.94; P = .001), a 38% reduction in positive examinations. Throughout the study period, there was a 67.4% increase in head and neck CTA ordering with a concomitant 38.1% decrease in positivity rate.

Multisystem factors contributing to redundant intracranial vascular imaging in the ED

PURPOSE

To evaluate the multisystem factors contributing to redundant neurovascular orders in the ED.

METHODS

This was an IRB-approved, retrospective study, performed at a single institution examining a 5-year history of redundant CTA/MRA head and neck (HN) exams performed in the ED for patients with no documented clinical change in mental status/neurological exam necessitating additional imaging. Factors contributing to redundant ordering including provider experience, synchronous order placement, and radiologist recommendations were examined. Additionally, the impact of duplicative imaging in terms of medical cost and ED length of stay was evaluated.

RESULTS

250 patients met inclusion criteria with both CTA/MRA of the HN performed during a single ED encounter (total 500 exams). 190 (76%) redundant exams were not recommended by a radiologist and contributed to an added ED length of stay of 3.6 h on average. Provider experience was not a significant contributing factor. 60 (24%) of redundant exams were recommended by a radiologist and were most frequently CTAs needed to clarify an area of artifact/high-grade stenosis/occlusion on a primary MRA exam.

CONCLUSION

Evaluation of contributing factors to redundant CTA/MRA HN exams ordering has highlighted multiple associated factors including provider experience, recommendations by radiologists for clarification of MRA findings, as well as systems processes related to synchronous CTA/MRA order placement.

Quantifying effects of blood pressure control on neuroimaging utilization in a large multi-institutional healthcare population

OBJECTIVES

Essential hypertension is a common chronic condition that can exacerbate or complicate various neurological diseases that may necessitate neuroimaging. Given growing medical imaging costs and the need to understand relationships between population blood pressure control and neuroimaging utilization, we seek to quantify the relationship between maximum blood pressure recorded in a given year and same-year utilization of neuroimaging CT or MR in a large healthcare population.

METHODS

A retrospective population-based cohort study was performed by extracting aggregate data from a multi-institutional dataset of patient encounters from 2016, 2018, and 2020 using an informatics platform (Cosmos) consisting of de-duplicated data from over 140 academic and non-academic health systems, comprising over 137 million unique patients. A population-based sample of all patients with recorded blood pressures of at least 50 mmHg DBP or 90 mmHg SBP were included. Cohorts were identified based on maximum annual SBP and DBP meeting or exceeding pre-defined thresholds. For each cohort, we assessed neuroimaging CT and MR utilization, defined as the percentage of patients undergoing ≥1 neuroimaging exam of interest in the same calendar year.

RESULTS

The multi-institutional population consisted of >38 million patients for the most recent calendar year analyzed, with overall utilization of 3.8-5.1% for CT and 1.5-2.0% for MR across the study period. Neuroimaging utilization increased substantially with increasing annual maximum BP. Even a modest BP increase to 140 mmHg systolic or 90 mmHg diastolic is associated with 3-4-fold increases in MR and 5-7-fold increases in CT same-year imaging compared to BP values below 120 mmHg / 80 mmHg.

CONCLUSION

Higher annual maximum recorded blood pressure is associated with higher same-year neuroimaging CT and MR utilization rates. These observations are relevant to public health efforts on hypertension management to mitigate costs associated with growing imaging utilization.

Mechanical thrombectomy in patients with acute ischemic stroke in the USA before and after time window expansion

BACKGROUND

In 2018, the time window for mechanical thrombectomy eligibility in patients with acute ischemic stroke increased from within 6 hours to within 24 hours of symptom onset. The purpose of this study was to evaluate the effect of window expansion on procedural and hospital volumes and patient outcomes at a national level.

METHODS

We conducted a retrospective cohort study of patients with acute ischemic stroke undergoing mechanical thrombectomy using data from the National Inpatient Sample. We compared the numbers of mechanical thrombectomy procedures and performing hospitals between 2017 and 2019 in the USA, and the proportion of patients discharged home/self-care, those with in-hospital mortality and post-procedural intracranial hemorrhage (2019 vs 2017) after adjustment for potential confounders.

RESULTS

The number of patients with ischemic stroke who underwent mechanical thrombectomy increased from 16 960 in 2017 to 28 120 in 2019. There was an increase in the number of hospitals performing mechanical thrombectomy (501 in 2017, 585 in 2019) and those performing ≥50 procedures/year (97 in 2017, 199 in 2019; P<0.001). The odds of in-hospital mortality decreased (OR 0.79, 95% CI 0.66 to 0.94, P=0.008) and the odds of intracranial hemorrhage increased (OR 1.18, 95% CI 1.06 to 1.31, P=0.003) in 2019 compared with 2017, with no change in odds of discharge to home.

CONCLUSIONS

The window expansion for mechanical thrombectomy for patients with acute ischemic stroke was associated with an increase in the numbers of mechanical thrombectomy procedures and performing hospitals with a reduction of in-hospital mortality in the USA.

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.

Diagnostic Imaging Utilization in the Emergency Department: Recent Trends in Volume and Radiology Work Relative Value Units

PURPOSE

The aim of this study was to quantify and characterize the recent trend in emergency department (ED) imaging volumes and radiology work relative value units (wRVUs) at level I and level III trauma centers.

METHODS

Total annual diagnostic radiology imaging volumes and wRVUs were obtained from level I and level III trauma centers from January 2014 to December 2021. Imaging volumes were analyzed by modality type, examination code, and location. Total annual patient ED encounters (EDEs), annual weighted Emergency Severity Index, and patient admissions from the ED were obtained. Data were analyzed using annual imaging volume or wRVUs per EDE, and percentage change was calculated.

RESULTS

At the level I trauma center, imaging volumes per EDE increased for chest radiography (5.5%), CT (35.5%), and MRI (56.3%) and decreased for ultrasound (-5.9%) from 2014 to 2021. Imaging volumes per EDE increased for ultrasound (10.4%), CT (74.6%), and MRI (2.0%) and decreased for chest radiography (-4.4%) at the level III trauma center over the same 8-year period. Total wRVUs per EDE increased at both the level I (34.9%) and level III (76.6%) trauma centers over the study period.

CONCLUSIONS

ED imaging utilization increased over the 8-year study period at both level I and level III trauma centers, with an increase in total wRVUs per EDE. There was a disproportionate increased utilization of advanced imaging, such as CT, over time. ED utilization trends suggest that there will be a continued increase in demand for advanced imaging interpretation, including at lower acuity hospitals, so radiology departments should prepare for this increased work demand.

Association of State Share of Nonphysician Practitioners With Diagnostic Imaging Ordering Among Emergency Department Visits for Medicare Beneficiaries

IMPORTANCE

The use of nonphysician practitioners (NPPs) in the emergency department (ED) continues to expand, yet little is known about associations between NPPs and ED imaging use.

OBJECTIVE

To investigate whether the state share of ED visits for which an NPP was the clinician of record is associated with imaging studies ordered, given that state NPP share is associated with state-level NPP scopes of practice.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study compared diagnostic imaging ordering patterns associated with ED visits based on 2005-2020 Medicare claims for a nationally representative 5% sample of fee-for-service beneficiaries. For all 50 states and the District of Columbia, the state NPP share of ED visits by year was used to represent state-specific practice patterns for NPPs and physicians and how those patterns have evolved over time. The analysis controlled for patient demographic characteristics, Charlson Comorbidity Index scores, ED visit severity, year, and principal diagnosis.

EXPOSURES

The share of ED visits in each state in each year (state share) for which an NPP was the evaluation and management clinician.

MAIN OUTCOMES AND MEASURES

The main outcomes were the number and modality of imaging studies associated with ED visits. Analyses were by logistic regression and generalized linear model with γ-distribution and log-link function.

RESULTS

Among 16 922 274 ED visits, 60.0% involved women, and patients' mean (SD) age was 70.3 (16.1) years. The share of all ED visits with an NPP as the clinician increased from 6.1% in 2005 to 16.6% in 2020. Compared with no NPPs, the presence of NPPs in the ED was associated with 5.3% (95% CI, 5.1%-5.5%) more imaging studies per ED visit, including a 3.4% (95% CI, 3.2%-3.5%) greater likelihood of any imaging order per ED visit and 2.2% (95% CI, 2.0%-2.3%) more imaging studies ordered per visit involving imaging.

CONCLUSIONS AND RELEVANCE

In this study, use of NPPs in the ED was associated with higher imaging use compared with the use of only physicians in the ED. Although expanded use of NPPs in the ED may improve patient access, the costs and radiation exposure associated with more imaging warrants additional study.

Updated Trends, Disparities, and Clinical Impact of Neuroimaging Utilization in Ischemic Stroke in the Medicare Population: 2012 to 2019

OBJECTIVE

The purpose of this study was to update trends, investigate sociodemographic disparities, and evaluate the impact on mortality of stroke neuroimaging across the United States from 2012 to 2019.

METHODS

Retrospective cohort study using CMS Medicare 5% Research Identifiable Files, representing consecutive ischemic stroke emergency department or hospitalized patients aged ≥65 years. A total of 85,547 stroke episodes with demographic and clinical information were analyzed using Cochran-Mantel-Haenszel tests and logistic regression. Outcome measures were neuroimaging (CT angiography [CTA], CT perfusion [CTP], MRI, MR angiography [MRA]) utilization, acute treatment (endovascular thrombectomy [EVT] and intravenous thrombolysis [IVT]), and mortality while in the hospital and at 30 days and 1 year post discharge.

RESULTS

Significantly increasing utilization trends for CTA (250%), CTP (428%) and MRI (18%), and a decreasing trend for MRA (-33%) were observed from 2012 to 2019 (P < .0001). Controlling for covariates in the logistic regression models, CTA and CTP were significantly associated with higher EVT and IVT utilization. Although CTA, MRI, and MRA were associated with lower mortality, CTP was associated with higher mortality post discharge. Less neuroimaging was performed in rural patients; older patients (≥80 years) had lower utilization of CTA, MRI, and MRA; female patients had lower rates of CTA; and Black patients had lower utilization of CTA and CTP.

CONCLUSIONS

CTA and CTP utilization increased in the Medicare ischemic stroke population from 2012 to 2019 and both were associated with greater EVT and IVT use. However, disparities exist in neuroimaging utilization across all demographic groups, and further understanding of the root causes of these disparities will be crucial to achieving equity in stroke care.

Trends in the Management of Headache Disorders in US Emergency Departments: Analysis of 2007-2018 National Hospital Ambulatory Medical Care Survey Data

We examined trends in management of headache disorders in United States (US) emergency department (ED) visits. We conducted a cross-sectional study using 2007−2018 National Hospital Ambulatory Medical Care Survey data. We included adult patient visits (≥18 years) with a primary ED discharge diagnosis of headache. We classified headache medications by pharmacological group: opioids, butalbital, ergot alkaloids/triptans, acetaminophen/nonsteroidal anti-inflammatory drugs (NSAIDs), antiemetics, diphenhydramine, corticosteroids, and intravenous fluids. To obtain reliable estimates, we aggregated data into three time periods: 2007−2010, 2011−2014, and 2015−2018. Using multivariable logistic regression, we examined medication, neuroimaging, and outpatient referral trends, separately. Among headache-related ED visits, opioid use decreased from 54.1% in 2007−2010 to 28.3% in 2015−2018 (Ptrend < 0.001). There were statistically significant increasing trends in acetaminophen/NSAIDs, diphenhydramine, and corticosteroids use (all Ptrend < 0.001). Changes in butalbital (6.4%), ergot alkaloid/triptan (4.7%), antiemetic (59.2% in 2015−2018), and neuroimaging (37.3%) use over time were insignificant. Headache-related ED visits with outpatient referral for follow-up increased slightly from 73.3% in 2007−2010 to 79.7% in 2015−2018 (Ptrend = 0.02). Reflecting evidence-based guideline recommendations for headache management, opioid use substantially decreased from 2007 to 2018 among US headache-related ED visits. Future studies are warranted to identify strategies to promote evidence-based treatment for headaches (e.g., sumatriptan, dexamethasone) and appropriate outpatient referral and reduce unnecessary neuroimaging orders in EDs.

Contemporary national trends and disparities for head CT use in emergency department settings: Insights from National Hospital Ambulatory Medical Care Survey (NHAMCS) 2007-2017

BACKGROUND

The exponential growth in CT utilization in emergency department (ED) until 2008 raised concerns regarding cost and radiation exposure. Head CT was one of the commonest studies. This led to mitigating efforts such as appropriate use guidelines, policy and payment reforms. The impact of these efforts is not fully understood. In addition, disparities in outcomes of acute conditions presenting to the ED is well known however recent trends in imaging utilization patterns and disparities are not well understood. In this study, we describe nationwide trends and disparities associated with head CT in ED settings between 2007 and 2014.

METHODS

We analyzed 2007-2017 National Hospital Ambulatory Medical Care Survey (NHAMCS) with the primary goal to assess the rate and patterns of head CT imaging in ED.

RESULTS

There were an estimated 117 million in 2007 and 139 million ED visits in 2017. There was a 4% increase in the any CT use in 2017 compared to 2007. No significant change in head CT utilization rate was seen. The 2007 head CT rate was 6.7% (95% CI: 6.1-7.3) compared to 7.7% (95% CI: 6.8-8.6) in 2017. Trauma, Headache and Dizziness are the top three indications for head CT use in the ED respectively. On adjusted analyses, significantly higher head CT utilization was seen in elderly, (age>65 yrs) and significantly lower utilization rate was seen in Non-Hispanic Black and Medicaid patients, and patients in rural locations.

CONCLUSIONS

Previously reported exponential growth of CT use in ED is no longer seen. In particular, there was no significant change in ED head CT use between 2007 and 2017. Headache and Dizziness remain commonly used indications despite limited utility in most clinical scenarios, indicating continued need for appropriate use of imaging. There is significantly lower CT utilization in Non-Hispanic Black, Medicaid patients and those in rural locations, suggesting disparities in diagnostic work-up in marginalized and rural populations. This underscores the need for standardizing care regardless of race, insurance status and location.

The natural history of non-functioning pituitary adenomas: A meta-analysis of conservatively managed tumors

BACKGROUND

Non-functioning pituitary adenomas (NFPA) are often discovered incidentally. The natural history of NFPA is not well understood, obfuscating evidence-based management decisions. Meta-data of radiographically followed NFPA may help guide conservative versus operative treatment of these tumors.

METHODS

We searched PubMed, Medline, Embase, and Ovid for studies with NFPA managed nonoperatively with radiographic follow-up. Studies on postoperative outcomes after NFPA resection and studies that did not delineate NFPA data from functional pituitary lesions were excluded. NFPA were divided into micro- and macroadenomas based on size at presentation. We performed a meta-analysis of aggregate data for length of follow-up, change in tumor size, rate of apoplexy, and need for resection during follow-up.

RESULTS

Our database search yielded 1787 articles, of which 19 were included for final analysis. The studies included 1057 patients with NFPA followed radiographically. Macroadenomas were significantly more likely to undergo growth (34% vs. 12%; p < 0.01) or apoplexy (5% vs. < 1%; p = 0.01) compared to microadenomas. Resection was performed in 11% of all NFPA patients during follow-up regardless of size at presentation. Meta-regression showed that surgery during follow-up was associated with macroadenomas and negatively associated with microadenomas that decreased in size.

CONCLUSION

Low-quality evidence suggests that NFPA classified as macroadenomas have an increased rate of growth and apoplexy during follow-up compared to microadenomas. A significant minority of all NFPA patients ultimately underwent surgery. In select patients, nonoperative management may be the appropriate strategy for NFPA. Macroadenomas may require closer follow-up.

Head and Neck CTA Utilization: Analysis of Ordering Frequency and Nonroutine Results Communication, With Focus on the Fifty Most Common Emergency Department Clinical Presentations

Background: Utilization of head and neck CTA in the emergency department (ED) has grown disproportionately to other neuroimaging examinations. Objective: To characterize utilization of head and neck CTA in the ED, comparing utilization and frequency of nonroutine results communication among patients' chief concerns. Methods: All adult ED visits for a single healthcare system from January 2014 to December 2017 were retrospectively reviewed. Variables recorded included chief concerns, whether head and neck CTA was performed, and, if so, whether the report documented nonroutine results communication. The fifty chief concerns resulting in the highest number of head and neck CTA examinations were identified. Frequencies of head and neck CTA ordering and of nonroutine results communication were calculated. A subset of reports documenting nonroutine communication were manually reviewed. Results: Head and neck CTA was ordered in 2.5% (17,903) of 708,145 ED visits in 236,476 patients (mean age 48.9±20.5 years; 110,952 male, 125,521 female, 3 unknown sex). Head and neck CTA was ordered for 833 distinct chief concerns. Nonroutine results communication was documented for 17.6% (31,55/17,903) of examinations. Among the fifty chief concerns associated with the highest number of examinations, frequency of ordering head and neck CTA ranged from <0.5% (five concerns) to 55.2% (stroke code), and frequency of nonroutine communication ranged from 5.6% (transient ischemic attack) to 67.5% (unresponsive). Chief concerns not among the fifty most common accounted for 50.0% (8956/17903) of examinations; these exhibited a collective frequency of nonroutine communication of 4.8% (429/8956). Manual review of 11.1% (350/3155) of reports with a nonroutine communication indicated an acute finding related to the indication in 51.1%, non-emergent but potentially explanatory finding in 28.0%, incidental finding in 28.0%, and communication of negative results in 6.9%. Conclusion: Head and neck CTA is ordered in 2.5% of ED visits for a wide range of chief concerns. Frequencies of ordering and of nonroutine results communication are highly variable among chief concerns. Acute indication-related findings account for half of nonroutine radiologist communications. Clinical Impact: Insight into patterns regarding head and neck CTA ordering and nonroutine results may help optimize patient selection and radiologist communications in the ED setting.

Increasing Utilization of Emergency Department Neuroimaging from 2007 to 2017

Background: The volume of emergency department (ED) visits and neuroimaging have grown since the start of the century. Little is known about this growth in the commercially insured and Medicare Advantage populations. Objective: To evaluate changing emergency department utilization of neuroimaging from 2007 to 2017 in both commercially insured and Medicare Advantage enrollees. Methods: Using patient-level claims from Optum's De-identified Clinformatics Data Mart database, which annually includes approximately 12 to 14 million commercial and Medicare Advantage health plan enrollees, annual ED utilization of head computed tomography (CT), head magnetic resonance (MR), head CT angiography (CTA), neck CTA, head MR angiography (MRA), neck MRA, and carotid duplex ultrasound (CDUS) were assessed from 2007 through 2017. To account for an aging sample population, utilization rates were adjusted using annual relative proportions of age groups and stratified by patient demographics, payer type, and provider state. Results: Between 2007 and 2017, age-adjusted ED neuroimaging utilization rates per 1000 ED visits increased 72% overall (compound annual growth rate [CAGR] 5%). This overall increase corresponded to an increase of 69% for head CT (CAGR 5%); 67% for head MRI (CAGR 5%); 1100% for head CTA (CAGR 25%); 1300% for neck CTA (CAGR 27%); 36% for head MRA (CAGR 3%); 52% for neck MRA (CAGR 4%); and a decrease of 8% for CDUS (CAGR -1%). The utilization of head CT and CTA of the head and neck per 1000 ED visits continuously increased in those 65 or older by 48% (CAGR 4%) and 1011% (CAGR 24%). Conclusion: Neuroimaging utilization in the ED grew considerably between 2007 and 2017, with growth of head and neck CTA far outpacing other modalities. Unenhanced head CT remains by far the dominant ED neuroimaging examination. Clinical Impact: The rapid growth of head and neck CTA observed in the fee-for-service Medicare population is also observed in the commercially insured and Medicare Advantage populations. The appropriateness of this growth should be monitored as the indications for CTA expand.

Disproportionate Use in Minor Trauma Is Driving Emergency Department Cervical Spine Imaging: An Injury Severity Score-Based Analysis

PURPOSE

Clinical practice guidelines intended to reduce unnecessary cervical spine imaging have yielded mixed results. We aimed to assess evolving emergency department (ED) cervical spine imaging utilization in patients with trauma by injury severity.

METHODS

Using 2009 to 2018 IBM MarketScan Commercial Databases, we identified ED trauma encounters, associated cervical spine imaging, and related diagnosis codes. We classified encounters by injury severity (minor, intermediate, major) using an International Classification of Disease code-derived Injury Severity Score algorithm and studied evolving imaging utilization using multivariable Poisson regression models.

RESULTS

Of all 11,346,684 ED visits for trauma, 7,753,914 (68.3%), 3,524,250 (31.1%), and 68,520 (0.6%) involved minor, intermediate, and major injuries, respectively. Overall cervical spine imaging increased 5.7% annually (incidence rate ratio [IRR] 1.057, P < .001) with radiography decreasing 2.7% annually (IRR 0.973, P < .001) and CT increasing 10.5% annually (IRR 1.105, P < .001). Radiography utilization remained unchanged for minor injuries (IRR 0.994, P = .14) but decreased for intermediate (IRR 0.928 versus minor, P < .001) and major (IRR 0.931 versus minor, P < .001) injuries. Increases in CT utilization were greatest for minor injuries (IRR 1.109, P < .001) with smaller increases in intermediate (IRR 0.960 versus minor, P < .001) and major (IRR 0.987 versus minor, P = .022) injuries.

CONCLUSIONS

Recent increases in cervical spine imaging in commercially insured patients with trauma seen in the ED have been largely related to increases in CT for patients with only minor injuries, in whom imaging utilization has been historically low. Further study is necessary to assess appropriateness, implications on costs and population radiation dose, and factors influencing ordering decision making.

Accuracy of Brain MRI Interpretation of Emergency Medicine Specialists Versus Radiologist and Neurologist in Suspected Acute Ischemic Stroke Patients; a Diagnostic Accuracy Study

Background: Despite numerous brain magnetic resonance imaging (MRI) utilization in the emergency department (ED), certainly, imaging alone is not enough, and it is necessary to have a correct interpretation by a physician who has sufficient skills in this regard. Objectives: Here, we decided to investigate the accuracy of interpreting brain MRI of suspected acute ischemic stroke (AIS) patients conducted by emergency medicine physicians (EMPs) in comparison with a radiologist and a neurologist. Methods: This diagnostic accuracy study was conducted from April to November 2019 in Tehran, Iran. All attending EMPs of one major educational, medical center, a radiologist, and a neurologist also participated. A set of brain MRI stereotypes related to patients suspected of having a AIS was randomly selected. By reviewing the brain MRI interpretation of EMPs, once in comparison with the radiologist and once in comparison with the neurologist, misinterpretations (presence or absence of findings compatible with the diagnosis of AIS) were extracted. Results: Brain MRI stereotypes of 287 suspected AIS patients were interpreted of these patients, 160 cases (55.7%) were male. The mean age of the study patients was 65.0 ± 14.1 (range of 18 to 98) years. The value of the agreement for diagnosis between EMPs and neurologists was 0.684 (95% CI: 0.580 to 0.787). Considering the neurologist as the gold standard, the accuracy of AIS diagnosis by the EMPs was 0.85% (95% CI: 79.3 to 89.6). The agreement value for diagnosis between EMPs and radiologist was 0.673 (95% CI: 0.553 to 0.794). Considering the radiologist as the gold standard, the accuracy of AIS diagnosis by the EMPs was 86.3% (95% CI: 79.8 to 91.3). The agreement value for diagnosis in these two groups was 0.752 (95% CI: 0.627 to 0.877). Conclusions: The findings of the current study revealed that the accuracy of brain MRI interpretation performed by the EMPs, compared with both neurologist and radiologist was proper.

Acute Kidney Injury in Acute Ischemic Stroke Patients in Clinical Trials

OBJECTIVES

Acute ischemic stroke patients are at risk of acute kidney injury due to volume depletion, contrast exposure, and preexisting comorbid diseases. We determined the occurrence rate and identified predictors associated with acute kidney injury in acute ischemic stroke patients.

SETTING

Multiple specialized ICUs within academic medical centers.

DESIGN

Post hoc analysis of pooled data from prospective randomized clinical trials.

PATIENTS

Acute ischemic stroke patients recruited within 3 hours or within 5 hours of symptom onset.

INTERVENTIONS

IV recombinant tissue plasminogen activator, endovascular treatment, IV albumin, or placebo.

MEASUREMENTS AND MAIN RESULTS

Serum creatinine levels from baseline and within day 5 or discharge were used to classify acute kidney injury classification into stages. Any increase in serum creatinine was seen in 697 (36.1%) and acute kidney injury was seen in 68 (3.5%) of 1,931 patients with acute ischemic stroke. Severity of acute kidney injury was grade I, II, and III in 3.1%, 0.4%, and 0.05% patients, respectively. Patients with albumin (5.5% compared with 2.6%; p = 0.001), preexisting hypertension (4.3% compared with 1.5%; p = 0.0041), and preexisting renal disease (9.1% compared with 3.0%; p < 0.0001) had higher risk of acute kidney injury. The risk of acute kidney injury was lower between those who either underwent CT angiography (2.0% compared with 4.7%; p = 0.0017) or endovascular treatment (1.6% compared with 4.2%; p = 0.0071). In the multivariate analysis, hypertension (odds ratio, 2.6; 95% CI, 1.2-5.6) and renal disease (odds ratio, 3.5; 95% CI, 1.9-6.5) were associated with acute kidney injury. The risk of death was significantly higher among patients with acute kidney injury (odds ratio, 2.7; 95% CI, 1.4-4.9) after adjusting for age and National Institutes of Health Stroke Scale score strata.

CONCLUSIONS

The occurrence rate of acute kidney injury in acute ischemic stroke patients was low and was not higher in patients who underwent CT angiogram or those who received endovascular treatment. Occurrence of acute kidney injury increased the risk of death within 3 months among acute ischemic stroke patients.

Decreasing CT Acquisition Time in the Emergency Department through Lean Management Principles

Background Emergency departments (EDs) rely on advanced imaging such as CT for diagnosis. Owing to increased ED volumes at the authors' institution, CT image acquisition became a significant bottleneck in ED patient throughput. Methods A multidisciplinary team was formed to solve this complex patient flow issue. Lean management principles were leveraged to identify process gaps and institute changes to achieve workflow improvements, remove process wastes, and improve patient throughput in the ED CT scanner. Process metrics such as percentage of CT examinations completed within 120 minutes and monthly median examination turnaround time (TAT) were tracked on a monthly basis. To measure impact, outcome metrics such as time savings from elimination of wasted steps were developed. Interventions Four projects including development of an ideal staffing model, a patient flow worksheet, revision of the CT patient screening form, and examination prioritization efforts were tested. Just-do-it activities such as revision of the CT angiography protocol ordering tool, optimizing scanner utilization, and improving communication and collaboration between the radiology department and ED were also attempted. Results After a phased rollout of changes over 6 months, the percentage of ordered ED CT examinations completed within 120 minutes increased by 10% (61%-71%); however, this improvement was sustained for only 6 weeks. Elimination of process inefficiencies resulted in a monthly median TAT reduction from 90-109 minutes to 82-106 minutes, and approximately 6 weeks (268 hours) of annualized full-time technologist time was saved. Conclusion Lean management tools can be leveraged to solve complex ED CT patient flow issues and reduce TAT. Online supplemental material is available for this article. ^©RSNA, 2021.

Brain Imaging in Patients With Dementia Visiting U.S. Emergency Departments

OBJECTIVE. This article aimed to assess changing use of brain imaging tests among patients with Alzheimer disease and vascular dementia who visited U.S. emergency departments (EDs) between 2006 and 2014. MATERIALS AND METHODS. Using the largest publicly available all-payer ED database, the Nationwide Emergency Department Sample, we identified a weighted cohort of 427,705 individuals with Alzheimer disease and 33,743 individuals with vascular dementia who visited U.S. EDs between 2006 and 2014. Logistic regression analyses were performed to identify factors associated with use. RESULTS. Between 2006 and 2014, ED visits among patients with Alzheimer disease and vascular dementia declined by 24.7% and 20.3%, respectively. However, there was a significant increase in utilization rates of head CT (from 4.4% to 11.1% in patients with Alzheimer disease and from 1.5% to 2.9% in patients with vascular dementia) and brain MRI (from 0.04% to 0.5% in patients with Alzheimer disease and 0.0% to 0.1% in those with vascular dementia) in the same time period. Among patients with Alzheimer disease, age, median income in patient ZIP code, day of the week of the ED visit, hospital teaching status, and hospital geographic region were significant predictors of imaging use. Among patients with vascular dementia, insurance type and hospital classification (urban vs rural) were significant predictors of imaging use. CONCLUSION. Despite declining ED visits, ED brain imaging in patients with Alzheimer disease and vascular dementia has increased. Various patient-specific and hospital-specific factors contribute to differential utilization rates.

Increasing use of CT requested by emergency department physicians in tertiary hospitals in Western Australia 2003-2015: an analysis of linked administrative data

OBJECTIVE

This study aimed to examine trends in number of CT scans requested by tertiary emergency department (ED) physicians in Western Australia (WA) from 2003 to 2015 across broad demographic and presentation characteristics, anatomical areas and presented symptoms.

DESIGN

An observational cross-sectional study over study period from 2003 to 2015.

SETTING

Linked administrative health service data at individual level from WA.

PARTICIPANTS

A total of 1 666 884 tertiary hospital ED presentations of people aged 18 years or older were included in this study MAIN OUTCOME MEASURE: Number of CT scans requested by tertiary ED physicians in an ED presentation.

METHODS

Poisson regression models were used to assess variation and trends in number of CT scans requested by ED physicians across demographic characteristics, clinical presentation characteristics and anatomical areas.

RESULTS

Over the entire study duration, 71 per 1000 ED episodes had a CT requested by tertiary ED physicians. Between 2003 and 2015, the rate of CT scanning almost doubled from 58 to 105 per 1000 ED presentations. After adjusted for all observed characteristics, the rate of CT scans showed a downward trend from 2009 to 2011 and subsequent increase. Males, older individuals, those attending ED as a result of pain, those with neurological symptoms or injury or with higher priority triage code were the most likely to have CT requested by tertiary ED physicians.

CONCLUSIONS

Noticeable changes in the number of CTs requested by tertiary ED physicians corresponded to the time frame of major health reforms happening within WA and nationally.

Increasing and disparate use of neuroimaging for adults and children with non-traumatic headaches in the US emergency departments: Opportunities for improvement

BACKGROUND

Optimization of neuroimaging practices for headache is considered a national priority; however, nationwide patterns and predictors of neuroimaging use for headache in the US emergency departments (EDs) are unknown.

OBJECTIVE

To analyze temporal neuroimaging utilization trends for adults and children with non-traumatic headache in the US EDs and identify factors predictive of neuroimaging use in this patient population.

METHODS

Retrospective cross-sectional study using the Healthcare Cost and Utilization Project Nationwide Emergency Department Sample database for administrative encounter-level data analysis of a nationwide group of adult and pediatric patients with primary diagnosis of headache (ICD-9CM codes 784.0x, 339.xx, 346.xx) visited the US EDs between January 1, 2006 and December 31, 2014. Temporal trends and independent predictors of neuroimaging use (e.g., patient and hospital characteristics, primary payment sources) were determined.

RESULTS

In 2006-2014, a weighted group of 18,146,302 patients with a primary diagnosis of non-traumatic headache visited US EDs. Advanced neuroimaging utilization increased from 18.6% (n = 350,777) to 34.8% (n = 756,895) in the total group, from 18.8% (n = 314,646) to 36.5% (n = 698,080) in the adult subgroup (+94.1%), and from 16.9% (n = 36,131) to 22.0% (n = 58,815) (+30.2%) in the pediatric subgroup (+87.0%) between 2006 and 2014. The strongest predictors of higher neuroimaging utilization were hospital location in the Northeast (OR 3.17, 95% CI 2.67-3.76) or South (OR 2.42, 95% CI 2.03-2.88) regions. Lower utilization of imaging was associated with weekend ED visits (OR 0.92, 95% CI 0.92-0.93), female gender (OR 0.82, 95% CI 0.81-0.83), and Medicare, Medicaid, or self-pay (vs. private insurance) encounters.

CONCLUSION

Neuroimaging utilization in patients with headache in US EDs nearly doubled in 2006-2014, and was used in 34.8% of all ED encounters in 2014. Utilization was higher and increased at faster rates for adults than children. In US EDs, imaging for headache is preferentially performed on commercially insured and male patients, at urban hospitals, in certain geographic regions, and on weekdays, raising concerns regarding disparate imaging use.

Emerging Challenges and Opportunities in the Evolution of Teleradiology

OBJECTIVE. In recent decades, teleradiology has expanded considerably, and many radiology practices now engage in intraorganizational or extraorganizational teleradiology. In this era of patient primacy, optimizing patient care and care delivery is paramount. This article provides an update on recent changes, current challenges, and future opportunities centered around the ability of teleradiology to improve temporal and geographic imaging access. We review licensing and regulations and discuss teleradiology in providing services to rural areas and assisting with disaster response, including the response to the coronavirus disease (COVID-19) pandemic. CONCLUSION. Teleradiology can help increase imaging efficiency and mitigate both geographic and temporal discrepancies in imaging care. Technologic limitations and regulatory hurdles hinder the optimal practice of teleradiology, and future attention to these issues may help ensure broader patient access to high-quality imaging across the United States.

Increasing emergency department utilization of brain imaging in patients with primary brain cancer

PURPOSE

To study changing emergency department (ED) brain imaging utilization in patients with primary brain cancers.

METHODS

Using 2006-2014 data from the Nationwide Emergency Department Sample (NEDS), we identified all patients with primary brain cancers visiting EDs and evaluated trends of head CT and brain MRI utilization. Multivariable logistic regression analyses were used to determine patient- and hospital-specific factors associated with brain imaging utilization.

RESULTS

A weighted cohort of 40,862 ED visits were included (mean age 55; 54% male), increasing from 3932 in 2006 to 5625 in 2014 (+ 43%). A total of 14.4% underwent brain imaging, with 13.2% undergoing CT, 2.3% undergoing MRI, and 1.1% undergoing both modalities. Between 2006 and 2014, there was a 104% increase in the rate of ED brain imaging (from 9.7% in 2006 to 19.8% in 2014). Factors associated with higher utilization of ED brain imaging in adults were non-teaching hospital status and Midwest and Northeast hospital regions (compared with the West). In pediatric patients, higher utilization was associated with older age, higher median household income of patient's ZIP code, and visits in rural, non-teaching hospitals located in the Midwest, South, and Northeast (compared with the West).

CONCLUSION

In US patients with primary brain cancer, the number of ED visits increased annually, and the utilization of ED head imaging examinations doubled in a recent 9-year period. A variety of sociodemographic characteristics are associated with a higher likelihood of imaging in both adult and pediatric patients.

Choosing wisely in emergency medicine: Early results and insights from the ACEP emergency quality network (E-QUAL)

PURPOSE

To characterize performance among ED sites participating in the Emergency Quality Network (E-QUAL) Avoidable Imaging Initiative for clinical targets on the American College of Emergency Physicians Choosing Wisely list.

METHODS

This was an observational study of quality improvement (QI) data collected from hospital-based ED sites in 2017-2018. Participating EDs reported imaging utilization rates (UR) and common QI practices for three Choosing Wisely targets: Atraumatic Low Back Pain, Syncope, or Minor Head Injury.

RESULTS

305 ED sites participated in the initiative. Among all ED sites, the mean imaging UR for Atraumatic Low Back Pain was 34.7% (IQR 26.3%-42.6%) for XR, 19.1% (IQR 11.4%-24.9%) for CT, and 0.09% (IQR 0%-0.9%) for MRI. The mean CT UR for Syncope was 50.0% (IQR 38.0%-61.4%). The mean CT UR for Minor Head Injury was 72.6% (IQR 65.6%-81.7%). ED sites with sustained participation showed significant decreases in CT UR in 2017 compared to 2018 for Syncope (56.4% vs 48.0%; 95% CI: -12.7%, -4.1%) and Minor Head Injury (76.3% vs 72.1%; 95% CI: -7.3%, -1.1%). There was no significant change in imaging UR for Atraumatic Back Pain for XR (36.0% vs 33.3%; 95% CI: -5.9%, -0;5%), CT (20.1% vs 17.7%; 95% CI: -5.1%, -0.4%) or MRI (0.8% vs 0.7%, 95% CI: -0.4%, -0.3%).

CONCLUSIONS

Early data from the E-QUAL Avoidable Imaging Initiative suggests QI interventions could potentially improve imaging stewardship and reduce low-value care. Further efforts to translate the Choosing Wisely recommendations into practice should promote data-driven benchmarking and learning collaboratives to achieve sustained practice improvement.

Redundant Neurovascular Imaging: Who Is to Blame and What Is the Value?

BACKGROUND AND PURPOSE

Excessive use of neurovascular imaging studies such as Doppler ultrasound, CTA, MRA, and DSA adds cost to the evaluation of patients with new neurologic deficits. We sought to determine to what extent redundant neurovascular imaging is generated by radiologists' recommendations and the agreement rates among modalities in this setting.

MATERIALS AND METHODS

The radiology reports of 300 consecutive patients admitted for acute stroke to determine the frequency of the following: 1) >1 neurovascular study performed, 2) recommendation for another study, 3) recommendation made by the radiologist, and 4) agreement rates among these redundant neurovascular imaging studies.

RESULTS

Among the 300 consecutive patients, 125 had redundant neurovascular imaging, accounting for 144 redundant studies. These included 75/125 redundant neurovascular imaging studies after MRA, 48/125 after CTA, and 2/125 after Doppler ultrasound. The radiologist recommended another vascular study in 22/125 (17.6%) patients; the rest of the recommendations were made by clinicians. The second study agreed with the first in 54.6% (12/22) of cases recommended by radiologists and 73.8% (76/103) recommended by clinicians (P value = .06). CTA agreed with MRA, carotid Doppler ultrasound, and DSA in 66.7%, 66.7%, and 55.6%, respectively. MRA agreed with Doppler ultrasound and DSA in 78.3% and 66.7%, respectively.

CONCLUSIONS

Of cases with redundant neurovascular imaging, most were generated by clinicians, but radiologists recommended redundant neurovascular imaging in 17.6% of patients; 81.8% occurred following MRA. Overall, most secondary studies (68.8%) confirmed the findings of the first study. Such low-value, same-result redundant neurovascular imaging was more common when clinicians ordered the studies (73.8%) than when radiologists ordered them (54.6%).

The Introduction and Development of the H-index for Imaging Utilizers: A Novel Metric for Quantifying Utilization of Emergency Department Imaging

OBJECTIVE

The objective was to develop a novel metric for quantifying patient-level utilization of emergency department (ED) imaging.

METHODS

Using 2009 to 2015 Truven Health MarketScan commercial claims and encounters database, all ED visits and associated imaging services were identified. To measure imaging resource intensity, total imaging relative value units (RVUs) were calculated for each patient per ED visit. An individual's annual imaging h-index is defined as the largest number, h, such that h ED visits by that individual in a given year is associated with total medical imaging RVUs of a value of at least h.

RESULTS

Over 7 years, in a sample of 86,506,362 privately insured individuals (232,919,808 person-years) in all 50 states and the District of Columbia, 38,973,716 ED visits were identified. A total of 9.5% of person-years had one ED visit and 2.7% had two or more (the remainder had none). From 2009 to 2015, the percentage of ED patients undergoing imaging increased from 25.1% to 34.6%. Individuals with two or more ED visits each associated with two or more imaging RVUs (ED imaging h-index ≥ 2) comprised 0.2% of the sample and 1.4% of ED visitors; however, they accounted for 4.0% of ED visits and the use of 18.6% of imaging resources. From 2009 to 2015, imaging resource allocation for such patients increased from 16.5% to 21.0%.

CONCLUSIONS

The ED imaging h-index allows identification of patients who undergo significant ED imaging, based on a single-digit patient-specific metric that incorporates both annual ED visit number and medical imaging resource intensity per visit. While ED patients with an ED imaging h-index ≥ 2 represented a minuscule fraction of privately insured individuals, they were associated with one-fifth of all ED imaging resources.

The Increasing Use of Emergency Department Imaging in the United States: Is It Appropriate?

OBJECTIVE. The purpose of this study was to study trends in utilization of imaging in emergency departments (ED) in relation to trends in ED visits and the specialties of the interpreting physicians. MATERIALS AND METHODS. This study was conducted with Medicare Part B Physician/Supplier Procedure Summary Master Files for 2004-2016 and Health Care Cost and Utilization Project (HCUP) data from 2006 to 2014. Yearly utilization was calculated per 1000 Medicare beneficiaries for different noninvasive imaging modalities performed during ED visits, and the specialties of the physicians making the interpretations were recorded. The number of ED visits by Medicare patients was obtained from the HCUP. RESULTS. The number of ED visits by Medicare fee-for-service patients increased 8.0% (from 20.0 million in 2006 to 21.6 million in 2014), and the total number of associated ED imaging examinations increased 38.4% (14.6 million to 20.2 million). The number of imaging examinations per ED visit was 0.73 in 2006, increasing to 0.94 by 2014. Utilization trends per 1000 Medicare fee-for-service enrollees in the ED for the major modalities were as follows: CT +153.0% (77.8 in 2004 to 196.7 in 2016), noncardiac ultrasound +134% (11.2 in 2004 to 26.2 in 2016), and radiography +30% (259 in 2004 to 336 in 2016). Utilization of MRI and nuclear medicine was very low. In 2016, radiologists interpreted 99.5% (CT), 99.2% (MRI), 98.0% (radiography), 87.6% (ultrasound), and 94.5% (nuclear medicine) of imaging examinations. CONCLUSION. Utilization of imaging in EDs is increasing not only in the Medicare population but also per ED visit. Radiologists strongly predominate in interpreting examinations in all modalities.

Current Clinical Practice Patterns of Self-Identified Nuclear Medicine Specialists

OBJECTIVE

The objective of our study was to study patterns of services rendered by U.S. physicians who self-identify as nuclear medicine (NM) specialists.

MATERIALS AND METHODS

Recent Medicare physician claims and demographic files were obtained and linked. NM specialists were defined as physicians self-identifying NM as their primary specialty on claims or as any of their specialties during enrollment. Using other self-identified specialties, we classified physicians as nuclear radiologists, nuclear cardiologists, exclusively NM physicians, or Others. Our primary outcome measure was the percentage of NM effort (in work relative value units [WRVUs]) per physician per specialty group. Secondary outcome measures included physician sociodemographic parameters and most common uniquely rendered services.

RESULTS

Nationally, 1583 physicians self-identified as NM specialists during the calendar years 2012 through 2015. The distribution of WRVUs attributed to NM varied widely by specialty group; most nuclear radiologists and nuclear cardiologists devoted 10% or less of their effort to NM services whereas most NM physicians devoted 90% or more of their effort to NM services. NM specialists were most commonly nuclear radiologists (52.2%) and men (80.3%) and practiced in urban (98.4%) and nonacademic settings (62.9%). NM physicians interpreted more general NM studies, nuclear radiologists interpreted more cross-sectional imaging studies, and nuclear cardiologists interpreted mostly nuclear cardiology studies, with a majority of their overall work attributed to clinical evaluation and management (E/M). E/M services accounted for less than 2% of WRVUs for both nuclear radiologists and NM physicians.

CONCLUSION

The work patterns of U.S. NM specialists is highly variable. Most NM physicians practice 90% or more NM, whereas most nuclear radiologists and nuclear cardiologists practice 10% or less NM. Commonly performed services vary considerably by specialty group.