Health Services Research: A Review for the Interventional Radiologist.

Health services research (HSR) is a multidisciplinary field which studies access to drivers of health care service utilization, the quality and cost of services, and their outcomes on groups of patients. Since its foundations in the 1960s, there has been a large focus on HSR and using large data sets to study real-world care. Because interventional radiology (IR) is a dynamic field with foundations in innovation, research often focuses on small-scale projects. This review will discuss HSR including data sources, focus areas, methodologies, limitations, and opportunities for future directions in IR.

Association of Incomplete Neurovascular Imaging After Emergency Department Encounters for Transient Ischemic Attack and Odds of Subsequent Stroke: A National Medicare Analysis.

BACKGROUND. Multisociety guidelines recommend urgent brain and neurovascular imaging for patients with transient ischemic attack (TIA), to identify and treat modifiable stroke risk factors. Prior research suggests that most patients with TIA who present to the emergency department (ED) do not receive prompt neurovascular imaging. OBJECTIVE. The purpose of this study was to evaluate the association between incomplete neurovascular imaging workup during ED encounters for TIA and the odds of subsequent stroke. METHODS. This retrospective study obtained data from the Medicare Standard Analytical Files for calendar years 2016 and 2017; these files contain 100% samples of claims for Medicare beneficiaries. Information was extracted using ICD 10th revision (ICD-10) and CPT codes. Those patients who were discharged from an ED encounter with a TIA diagnosis and who underwent brain CT or brain MRI during or within 2 days of the encounter were identified. Patients were considered to have complete neurovascular imaging if they underwent cross-sectional vascular imaging of both the brain (brain CTA or brain MRA) and neck (neck CTA, neck MRA, or carotid ultrasound) during or within 2 days of the encounter. The association between incomplete neurovascular imaging and a new stroke diagnosis within the subsequent 90 days was tested by multivariable logistic regression analysis. RESULTS. The sample included 111,417 patients (47,370 men, 64,047 women; 26.0% older than 84 years) who had TIA ED encounters. A total of 37.3% of patients (41,592) had an incomplete neurovascular imaging workup. A new stroke diagnosis within 90 days of the TIA ED encounter occurred in 4.4% (3040/69,825) of patients with complete neurovascular imaging versus 7.0% (2898/41,592) of patients with incomplete neurovascular imaging. Incomplete neurovascular imaging was associated with increased likelihood of stroke within 90 days (OR, 1.30 [95% CI, 1.23-1.38]) after adjustment for patient characteristics (age, sex, race and ethnicity, high-risk comorbidities, median county household income) and hospital characteristics (region, rurality, number of beds, major teaching hospital designation). CONCLUSION. TIA ED encounters with incomplete neurovascular imaging were associated with higher odds of subsequent stroke occurring within 90 days. CLINICAL IMPACT. Increased access to urgent neurovascular imaging for patients with TIA may represent a target that could facilitate detection and treatment of modifiable stroke risk factors.

Views of Diagnostic Radiology Residency Program Directors Regarding Methods to Increase Female and Under-Represented in Medicine Residents: A Cross-sectional Study.

RATIONALE AND OBJECTIVES: Diagnostic radiology remains one of the least diverse medical specialties. Recent reports have found that the number of female and under-represented in medicine (URiM) residents have not increased despite efforts to increase representation over the last decade. Given the critical role of residency program directors in selecting diverse applicants, this study was performed to identify which strategies were most preferred to increase the number of female and/or URiM residents by directors of diagnostic radiology residency training programs. MATERIALS AND METHODS: This was an anonymous, cross-sectional study of diagnostic radiology residency program directors that included a survey about program characteristics, demographics, and strategies to increase the number of female and/or URiM residents. RESULTS: The questionnaire was submitted to 181 potential participants with a 19.9% response rate. The most preferred strategies to increase diversity involved directly recruiting medical students, promoting mentorship, increasing the number of diverse teaching faculty, and unconscious bias training. The least supported strategies included deemphasizing exam scores, accepting more international graduates, accepting a minimum number of female and/or URiM applicants, and de-identifying applications. Female and/or URiM program directors indicated a statistically significant preference for medical student recruitment and providing an opportunity to discuss workplace issues for female and/or URiM trainees (p < 0.05). CONCLUSION: Diagnostic radiology residency program directors endorsed a wide variety of strategies to increase diversity. Recruitment of female and/or URiM medical students and promoting the number of diverse faculty members and mentorship of trainees by these faculty appear to be the most preferred strategies to increase female and/or URiM residents. Female and/or URiM program directors placed a greater importance on recruiting diverse applicants and supporting safe discussion of workplace issues faced by female and/or URiM radiology residents.

Healthcare Disparities in Interventional Radiology.

Racial, ethnic, and sex-based healthcare disparities have been documented for the past several decades. Nonetheless, disparities remain firmly entrenched in our care delivery systems, with multiple contributing factors, including patient interactions with care providers, systemic barriers to access, and socioeconomic determinants of health. Interventional radiology is also subject to these drivers of health inequity. In this review, documented disparities for the most common conditions being addressed by interventional radiologists are summarized; their magnitude is quantified where relevant, and underlying drivers are identified. Specific examples are provided to illustrate how medical, cultural, and socioeconomic factors interact to produce unequal outcomes. By outlining known disparities and common contributors, this review aims to motivate future efforts to mitigate them.

A Practical Guide to Use of Publicly Available Data Sets for Observational Research in Interventional Radiology.

Observational data research studying access, utilization, cost, and outcomes of image-guided interventions using publicly available "big data" sets is growing in the interventional radiology (IR) literature. Publicly available data sets offer insight into real-world care and represent an important pillar of IR research moving forward. They offer insights into how IR procedures are being used nationally and whether they are working as intended. On the other hand, large data sources are aggregated using complex sampling frames, and their strengths and weaknesses only become apparent after extensive use. Unintentional misuse of large data sets can result in misleading or sometimes erroneous conclusions. This review introduces the most commonly used databases relevant to IR research, highlights their strengths and limitations, and provides recommendations for use. In addition, it summarizes methodologic best practices pertinent to all data sets for planning and executing scientifically rigorous and clinically relevant observational research.

Lost to Follow-Up: A Nationwide Analysis of Patients With Transient Ischemic Attack Discharged From Emergency Departments With Incomplete Imaging.

PURPOSE: Imaging guidelines for transient ischemic attack (TIA) recommend that patients undergo urgent brain and neurovascular imaging within 48 hours of symptom onset. Prior research suggests that most patients with TIA discharged from the emergency department (ED) do not complete recommended TIA imaging workup during their ED encounters. The purpose of this study was to determine the nationwide percentage of patients with TIA discharged from EDs with incomplete imaging workup who complete recommended imaging after discharge. METHODS: Patients discharged from EDs with the diagnosis of TIA were identified from the Medicare 5% sample for 2017 and 2018 using International Classification of Diseases, tenth rev, Clinical Modification codes. Imaging performed was identified using Current Procedural Terminology codes. Incomplete imaging workup was defined as a TIA encounter without cross-sectional brain, brain-vascular, and neck-vascular imaging performed within the subsequent 30 days of the initial ED encounter. Patient- and hospital-level factors associated with incomplete TIA imaging were analyzed in a multivariable logistic regression. RESULTS: In total, 6,346 consecutive TIA encounters were analyzed; 3,804 patients (59.9%) had complete TIA imaging workup during their ED encounters. Of the 2,542 patients discharged from EDs with incomplete imaging, 761 (29.9%) completed imaging during the subsequent 30 days after ED discharge. Among patients with TIA imaging workup completed after ED discharge, the median time to completion was 5 days. For patients discharged from EDs with incomplete imaging, the odds of incomplete TIA imaging at 30 days after discharge were highest for black (odds ratio, 1.84; 95% confidence interval, 1.27-2.66) and older (≥85 years of age; odds ratio, 2.41; 95% confidence interval, 1.78-3.26) patients. Reference values were age cohort 65 to 69 years; male gender; white race; no co-occurring diagnoses of hypertension, hyperlipidemia, or diabetes mellitus; household income > $63,029; hospital in the Northeast region; urban hospital location; hospital size > 400 beds; academically affiliated hospital; and facility with access to MRI. CONCLUSIONS: Most patients discharged from EDs with incomplete TIA imaging workup do not complete recommended imaging within 30 days after discharge.

Changes in the National Endovascular Management of Femoropopliteal Arterial Disease: An Analysis of the 2011-2019 Medicare Data.

PURPOSE: To describe national trends in the utilization of endovascular approaches (including balloon angioplasty, atherectomy, and stent placement) for the management of femoropopliteal peripheral arterial disease (PAD). MATERIALS AND METHODS: The Medicare Physician/Supplier Procedure Summary dataset containing 100% of Part B claims was interrogated for years 2011-2019. The Current Procedural Terminology codes specific for femoropopliteal angioplasty, stent placement, and atherectomy were used to create summary statistics for utilization by year, place of service (hospital inpatient, hospital outpatient, and office-based laboratory), and provider specialty (cardiology, radiology, and surgery). RESULTS: The use of atherectomy increased from 34,732 (33%) procedures in 2011 to 75,435 (53%) procedures in 2019, and atherectomy became the dominant treatment strategy for femoropopliteal PAD. The relative utilization of stent placement (36,793 [35%] to 28,899 [20%]) and angioplasty only (34,398 [32%] to 38,228 [27%]) decreased concomitantly from 2011 to 2019. By 2019, the use of atherectomy was twofold higher in office-based laboratories than in the outpatient hospital setting (44,767 and 20,901, respectively). Treatment strategy varied by provider specialty in 2011 when cardiologists used atherectomy most frequently (17,925 [43%]), whereas radiologists used angioplasty alone (5,928 [6%]) and surgeons stented (18,009 [37%]) most frequently. By 2019, all specialties utilized atherectomy most frequently (29,564 [59%] for cardiology, 10,912 [58%] radiology, and 33,649 [47%] surgery). CONCLUSIONS: The national approach to endovascular management of femoropopliteal PAD has changed since 2011 toward an implant-free strategy, including a multifold increase in the use of atherectomy. Discordant rates of atherectomy use between the ambulatory hospital and office-based settings highlight the need for comparative effectiveness studies to guide management.

High Prevalence of Transjugular Intrahepatic Portosystemic Shunt Creation Without Prior Endoscopy During Acute Variceal Bleeding Hospitalization in the United States.

Current clinical guidelines by both American Association for the Study of Liver Disease and European Association for the Study of the Liver recommend endoscopy in all patients admitted with acute variceal bleeding within 12 hours of admission. Transjugular intrahepatic portosystemic shunt (TIPS) creation may be considered in patients at high risk if hemorrhage cannot be controlled endoscopically. We conducted a cross-sectional observational study to assess how frequently TIPS is created for acute variceal bleeding in the United States without preceding endoscopy. Adult patients undergoing TIPS creation for acute variceal bleeding in the United States (n = 6,297) were identified in the last 10 available years (2007-2016) of the National Inpatient Sample. Hierarchical logistic regression was used to examine the relationship between endoscopy nonutilization and hospital characteristics, controlling for patient demographics, income level, insurance type, and disease severity. Of 6,297 discharges following TIPS creation for acute variceal bleeding in the United States, 31% (n = 1,924) did not receive first-line endoscopy during the same encounter. Rates of "no endoscopy" decreased with increasing population density of the hospital county (nonmicropolitan counties 43%, n = 114; mid-size metropolitan county 35%, n = 513; and central county with >1 million population 23%, n = 527) but not by hospital teaching status (n = 1,465, 32% teaching vs. n = 430, 26% nonteaching; P = 0.10). Higher disease mortality risk (odds ratio, 0.42; 95% confidence interval, 0.22-0.80; P = 0.02) was associated with lower odds of noncompliance. Conclusion: One third of all patients undergoing TIPS creation for acute variceal bleeding in the United States do not receive first-line endoscopy during the same encounter. Patients admitted to urban hospitals are more likely to receive guideline-concordant care.

Redundant Imaging in Transient Ischemic Attack: Evidence From the Nationwide Emergency Department Sample.

PURPOSE: Increasing emergency department (ED) compliance with transient ischemic attack (TIA) imaging guidelines has previously been demonstrated, along with a substantial rise in imaging utilization over the past decade. The purpose of this study was to characterize the most commonly used combinations of imaging studies during ED workup of TIA and to quantify prevalence of redundant imaging (RI). METHODS: TIA discharges from EDs in the United States from 2006 to 2017 were identified in the Nationwide Emergency Department Sample. Brain and neurovascular imaging obtained during the encounter was identified using Current Procedural Terminology codes. RI was defined as an ED encounter with any duplicate cross-sectional brain, brain-vascular, or neck-vascular imaging. Patient demographics and hospital characteristics were incorporated into a multivariable logistic regression analysis to identify significant associations with RI. RESULTS: There were 184,870 discharges with TIA from EDs in 2017. RI (brain) was observed in 55,513 (30%) of encounters. RI (brain-vascular) and RI (neck-vascular) imaging was identified in 5,149 (2.8%) and 1,325 (0.7%) of encounters, respectively. Decreased odds of obtaining RI was observed in Medicaid patients (odds ratio [OR]: 0.72, 95% confidence interval [CI]: 0.64-0.81), non-trauma centers (OR: 0.49, 95% CI: 0.26-0.93), rural hospital locations (OR: 0.18, 95% CI: 0.11-0.29), and weekend encounters (OR: 0.9, 95% CI: 0.85-0.96). Trend analysis from 2006 to 2017 demonstrated a rise in RI (brain) from 2.3% of encounters in 2006 to 30% of encounters in 2017. RI for patients discharged from EDs with TIA in 2017 resulted in additional charges of approximately US$8,670,832. CONCLUSION: Increased imaging utilization for TIA workup across EDs in the United States is associated with rising use of redundant imaging. We identify imaging practices that could be targeted to mitigate health care expenditures while adhering to TIA imaging guidelines.

Comparative efficacy and safety of the Captus device for inferior vena cava filter retrieval.

PURPOSE: Retrievable inferior vena cava filters (IVCF) have been increasingly used for mechanical pulmonary embolism prophylaxis since their development. The Captus Vascular Retrieval System (Avantec Vascular, Sunnyvale, California) is a new device developed for retrieval of IVCF. This study compared the safety and efficacy of the new Captus device against the existing EnSnare Endovascular Snare System (Merit Medical, South Jordan, Utah) for IVCF retrieval. METHODS: Patients undergoing IVCF retrieval at a single institution between July 2015 and July 2020 were retrospectively identified. All adult patients (>18 years) undergoing filter retrieval with either Captus or Ensnare were included. Technical success and complications were compared by device. A complexity score was assigned to each case to adjust for selection bias. Logistic regression was used to model the association between device type and primary technical success. RESULTS: 99 IVCF retrievals met inclusion criteria, 59 with Captus and 40 with Ensnare. The majority of the cohort consisted of low complexity cases (n = 51, 86% Captus versus n = 31, 78% Ensnare; p = 0.28). Technical success for low and medium complexity retrievals was 88% and 62% with Captus and 96% and 33% with Ensnare. There was no significant association between device type and technical success, adjusting for case complexity (Captus OR 0.55, 95% CI 0.08-2.72, p = 0.49). There were no device-related complications. CONCLUSION: No statistically significant difference in device technical success or complications between the Ensnare and Captus devices for uncomplicated IVCF retrieval. PRECIS: The Captus Vascular Retrieval System is a new device for IVC filter retrieval which has similar technical success to the existing EnSnare.

Utilization and Outcomes of Cholecystostomy and Cholecystectomy in Patients Admitted With Acute Cholecystitis: A Nationwide Analysis.

OBJECTIVE. The purpose of this study was to report national utilization trends and outcomes after percutaneous cholecystostomy, cholecystectomy, or no intervention among patients admitted to hospitals with acute cholecystitis. MATERIALS AND METHODS. The Nationwide Inpatient Sample was queried from 2005 to 2014. Admissions were identified and stratified into treatment groups of percutaneous cholecystostomy, cholecystectomy, and no intervention on the basis of International Classification of Diseases, 9th revision, codes. Outcomes, including length of stay, inpatient mortality, and complications including hemorrhage and bile peritonitis, were identified. Multivariate analysis was performed to identify mortality risk by treatment type after adjustment for baseline comorbidities and risk of mortality. RESULTS. Among 2,550,013 patients (58.6% women, 41.4% men; mean age, 55.9 years) admitted for acute cholecystitis over the study duration, 73,841 (2.9%) patients underwent percutaneous cholecystostomy, 2,005,728 (78.7%) underwent cholecystectomy, and 459,585 (18.0%) did not undergo either procedure. Use of percutaneous cholecystostomy increased from 2985 procedures in 2005 to 12,650 in 2014. The percutaneous cholecystostomy cohort had a higher mean age (70.6 years) than the other two groups (cholecystectomy, 53.8 years; no intervention, 62.5 years), a higher mean comorbidity index (cholecystostomy, 3.74; cholecystectomy, 1.77; no intervention, 2.65), and a higher mean risk of mortality index (cholecystostomy, 2.88; cholecystectomy, 1.45; no intervention, 2.07) (p < .05). Unadjusted inpatient all-cause mortality was 10.1% in the percutaneous cholecystostomy, 0.8% in the cholecystectomy, and 5.2% in the no intervention cohorts. After adjustment for baseline mortality risk, percutaneous cholecystostomy (odds ratio, 0.78; 95% CI, 0.76-0.81) and cholecystectomy (odds ratio, 0.42; 95% CI, 0.41-0.43) were associated with reduced mortality compared with no intervention. CONCLUSION. Use of percutaneous cholecystostomy is increasing among patients admitted with acute cholecystitis. After adjustment for baseline comorbidities, percutaneous cholecystostomy is associated with improved odds of survival compared with no intervention.

Ethnoracial Disparity in Hospital Survival following Transjugular Intrahepatic Portosystemic Shunt Creation for Acute Variceal Bleeding in the United States.

PURPOSE: To investigate the magnitude of racial/ethnic differences in hospital mortality after transjugular intrahepatic portosystemic shunt (TIPS) creation for acute variceal bleeding and whether hospital care processes contribute to them. METHODS: Patients aged ≥18 years undergoing TIPS creation for acute variceal bleeding in the United States (n = 10,331) were identified from 10 years (2007-2016) available in the National Inpatient Sample. Hierarchical logistic regression was used to examine the relationship between patient race and inpatient mortality, controlling for disease severity, treatment utilization, and hospital characteristics. RESULTS: A total of 6,350 (62%) patients were White, 1,780 (17%) were Hispanic, and 482 (5%) were Black. A greater proportion of Black patients were admitted to urban teaching hospitals (Black, n = 409 (85%); Hispanic, n = 1,310 (74%); and White, n = 4,802 (76%); P < .001) and liver transplant centers (Black, n = 215 (45%); Hispanic, n = 401 (23%); and White, n = 2,267 (36%); P < .001). Being Black was strongly associated with mortality (Black, 32% vs non-Black, 15%; odds ratio, 3.0 [95% confidence interval, 1.6-5.8]; P = .001), as assessed using the risk-adjusted regression model. This racial disparity disappeared in a sensitivity analysis including only patients with a maximum Child-Pugh score of 13 (odds ratio 1.2 [95% confidence interval, 0.4-3.6]; P = .68), performed to compensate for the absence of Model for End-stage Liver Disease scores. Ethnoracial differences in access to teaching hospitals, liver transplant centers, first-line endoscopy, and transfusion did not significantly contribute (P > .05) to risk-adjusted mortality. CONCLUSIONS: Black patients have a 2-fold higher inpatient mortality than non-Black patients following TIPS creation for acute variceal bleeding, possibly related to greater disease severity before the procedure.

Comparative effectiveness of posttreatment imaging modalities for Medicare patients with advanced head and neck cancer.

BACKGROUND: Persistent controversy exists with regard to how and when patients with head and neck cancer should undergo imaging after definitive therapy. The current study was conducted to evaluate whether the type of imaging modality used in posttreatment imaging impacts cancer-specific survival for patients with advanced head and neck squamous cell carcinoma. METHODS: A retrospective study of National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) program-Medicare-linked data in patients with an advanced stage of the 3 most common head and neck malignancies (oral cavity, oropharynx, and larynx) was conducted. Hazard ratios and 95% CIs for cancer-specific survival were estimated for patients diagnosed with any of these cancers between 2006 and 2015. RESULTS: Significant improvement with regard to cancer-specific survival was observed among patients with American Joint Committee on Cancer stage III and stage IVA laryngeal cancer who underwent positron emission tomography (PET) and/or computed tomography (CT) imaging during the first 6 months after receipt of definitive treatment (hazard ratio, 0.517; 95% CI, 0.33-0.811) compared with those who underwent CT. There was a trend toward an improvement in cancer-specific survival among patients with oral cavity or oropharyngeal malignancies who underwent PET/CT imaging, but it did not reach statistical significance. CONCLUSIONS: Compared with CT imaging, posttreatment imaging with PET was associated with improved survival in patients with advanced laryngeal carcinoma.

Cost Analysis of Dialysis Access Maintenance Interventions across Physician Specialties in U.S. Medicare Beneficiaries.

Background Dialysis maintenance interventions account for billions of dollars in U.S. Medicare spending and are performed by multiple medical specialties. Whether Medicare costs differ by physician specialty is, to the knowledge of the authors, not known. Purpose To assess patency-adjusted costs of endovascular dialysis access maintenance by physician specialty. Materials and Methods In this retrospective longitudinal cohort study, patients who were beneficiaries of Medicare undergoing their first arteriovenous access placement in 2009 were identified by using billing codes in the 5% Limited Data Set. By tracking their utilization data through 2014, postintervention primary patency and aggregate payments associated with maintenance interventions were calculated. Unadjusted payments per year of access patency gain were compared across physician specialty. A general linear mixed-effects model adjusted for covariates was used, as follows: patient characteristics, access type (fistula vs graft), clinical severity, type of intervention (angioplasty, stent, thrombolysis), clinical location (hospital outpatient vs office-based laboratory), and resource utilization (operating room use, anesthesia use). Results First arteriovenous access was performed in 1479 beneficiaries (mean age, 63 years ± 15 [standard deviation]; 820 men) in 2009. Through 2014, 8166 maintenance interventions were performed in this cohort. Unadjusted mean Medicare payments for each incremental year of patency were as follows: $71 000 for radiologists, $89 000 for nephrologists, and $174 000 for surgeons. Billing for operating room (41.8% [792 of 1895], surgery; 10.2% [277 of 2709], nephrology; and 31.1% [1108 of 3562], radiology) and anesthesia (19.9% [377 of 1895], surgery; 2.6% [70 of 2709], nephrology; 4.7% [170 of 3562], radiology) varied by specialty and accounted for 407% and 132% higher payments, respectively. After adjusting for clinical severity and location, type of intervention, and resource utilization, nephrologists and surgeons had 59% (95% confidence interval: 44%, 73%; P < .001) and 57% (95% confidence interval: 43%, 72%; P < .001) higher payments, respectively, for the same patency gain compared with radiologists. Operating room use and anesthesia services were major drivers of higher cost, with 407% (95% confidence interval: 374%, 443%; P < .001) and 132% (95% confidence interval: 116%, 150%; P < .001) higher costs, respectively. Conclusion Patency-adjusted payments for hemodialysis access maintenance differed by physician specialty, driven partly by discrepant rates of billing for operating room and anesthesia use. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by White in this issue.

Compliance With Imaging Guidelines for Workup of Transient Ischemic Attack: Evidence From the Nationwide Emergency Department Sample.

BACKGROUND AND PURPOSE: Multiple societal guidelines recommend urgent brain and neurovascular imaging in patients with transient ischemic attack (TIA) to identify and treat risk factors that may lead to future stroke. The purpose of this study was to evaluate whether national imaging utilization for workup of TIA complies with society guidelines. METHODS: Analysis utilized the Nationwide Emergency Department Sample. Primary analysis was performed on a 2017 cohort, and secondary trend analysis was performed on cohorts from 2006 to2017. Patients diagnosed and discharged from emergency departments with TIA were identified using International Classification of Diseases, Ninth Revision and Tenth Revision codes. Brain and neurovascular imaging obtained during the encounter was identified using Current Procedural Terminology codes. Demographics, health insurance, patient income, and hospital-type covariates were analyzed using a hierarchical multivariable logistic regression analysis to identify predictors of obtaining neurovascular imaging during an emergency department encounter. RESULTS: In 2017, there were 167 999 patients evaluated and discharged from emergency departments with TIA. The percentage of patients receiving brain and neurovascular imaging was 78.5% and 43.2%, respectively. The most common imaging workup utilized was a solitary computed tomography-brain without any neurovascular imaging (30.9% of encounters). Decreased odds of obtaining neurovascular imaging was observed in Medicaid patients (odds ratio, 0.65 [95% CI, 0.58-0.74]), rural hospitals (odds ratio, 0.26 [95% CI, 0.17-0.41]), nontrauma centers (odds ratio, 0.40 [95% CI, 0.21-0.74]), and weekend encounters (odds ratio, 0.91 [95% CI, 0.85-0.96]). Trend analysis demonstrated a steady rise in brain and neurovascular imaging in 2006 from 34.9% and 6.8% of encounters, respectively, to 78.5% and 43.2% of encounters in 2017. CONCLUSIONS: Compliance with imaging guidelines is improving; however, the majority of TIA patients discharged from the emergency department do not receive recommended neurovascular imaging during their encounter. Follow-up studies are needed to determine whether delayed or incomplete vascular screening increases the risk of future stroke.