Changes in the Radiology Practice Landscape and Indicators of Practice Consolidation From 2014 to 2023.

Background: A range of economic and health policy incentives are leading to ongoing consolidation among payers, hospitals, and physician practices. Objective: To evaluate consolidation among radiologists' affiliated practices through 2023, analyze the impact of consolidation on such practices' specialty mix and size, and assess radiologists' new affiliations after prior practices cease. Methods: CMS data from 2014 to 2023 were used to identify all radiologists nationally along with their affiliated practices. Practices were categorized based on the specialty mix of all affiliated physicians as radiology-only or multispecialty; multispecialty practices were further categorized as radiology-majority, other-specialty-majority,or no-majority-specialty. Practices that ceased (i.e., became absent within CMS data) were identified. Temporal shifts were assessed, to infer consolidation patterns. Results: From 2014 to 2023, the number of Medicare-enrolled radiologists increased 17.3% from 30,723 to 36,024, while their number of affiliated practices decreased 14.7% from 5059 to 4313. The number of radiology-only, radiology-majority, other-specialty-majority, and no-majority practices changed by -31.8% (3104 to 2118), 10.8% (402 to 446), -5.7% (615 to 580), and 24.6% (938 to 1169), respectively. The number of practices with 1-2, 3-9, 10-24, 25-49, 50-99, and ≥100 radiologists changed by -18.7% (2233 to 1815), -34.4% (1406 to 923), -25.2% (910 to 681), 33.2% (352 to 469), 121.6% (125 to 277), and 348.5% (33 to 148). A total of 3494 practices ceased, including 2281 radiology-only practices. Among 3854 radiologists for whom their only affiliation was a ceased radiology-only practice, their subsequent-year affiliation was a radiology-only practice in 54.3% and a multispecialty practice type in the remaining instances. Conclusions: An overall decrease in the number of radiology practices and concurrent growth in the number of radiologists was mirrored by shifts from small toward large practices and from radiology-only toward multispecialty practices, consistent with ongoing practice consolidation. While determining causes of consolidation were beyond this study's scope, the shifts may relate to economic incentives and legislative changes favoring large multispecialty practices. Clinical Impact: Radiologists' continued consolidation into large multispecialty practices may facilitate subspecialization and greater negotiating power in payor contracting. Yet radiologists may prefer smaller and/or radiology-only practices for autonomy and influence on practice structure.

Financial Viability of the No Surprises Act Independent Dispute Resolution Process: Radiology and Other Hospital-Based Specialties.

BACKGROUND. The federal No Surprises Act (NSA), designed to eliminate surprise medical billing for out-of-network (OON) care for circumstances beyond patients' control, established the independent dispute resolution (IDR) process to settle clinician-payer payment disputes for OON care. OBJECTIVE. The purpose of our study was to assess the fraction of OON claims for which radiologists and other hospital-based specialists can expect to at least break even when challenging payer-determined payments through the NSA IDR process, as a measure of the process's financial viability. METHODS. This retrospective study extracted claims from a national commercial database (Optum's deidentified Clinformatics Data Mart) for hospital-based specialties occurring on the same day as in-network emergency department (ED) visits or inpatient stays from January 2017 to December 2021. OON claims were identified. OON claims batching was simulated using IDR rules. Maximum potential recovered payments from the IDR process were estimated as the difference between the charges and the allowed amount. The percentages of claims for which the maximum potential payment and one-quarter of this amount (a more realistic payment recovery estimate) would exceed IDR fees were determined, using US$150 and US$450 fee thresholds to approximate the range of final 2024 IDR fees. These values represented the percentage of OON claims that would be financially viable candidates for IDR submission. RESULTS. Among 76,221,264 claims for hospital-based specialties associated with in-network ED visits or inpatient stays, 1,482,973 (1.9%) were OON. The maximum potential payment exceeded fee thresholds of US$150 and US$450 for 55.0% and 32.1%, respectively, of batched OON claims for radiologists and 76.8% and 61.3% of batched OON claims for all other hospital-based specialties combined. At payment of one-quarter of that amount, these values were 26.9% and 10.6%, respectively, for radiologists and 56.6% and 38.4% for all other hospital-based specialties combined. CONCLUSION. The IDR process would be financially unviable for a substantial fraction of OON claims for hospital-based specialists (more so for radiology than for other such specialties). CLINICAL IMPACT. Although the NSA enacted important patient protections, IDR fees limit clinicians' opportunities to dispute payer-determined payments and potentially undermine their bargaining power in contract negotiations. Therefore, IDR rulemaking may negatively impact patient access to in-network care.

Radiologists' Out-of-Network Billing Trends, 2007 to 2021.

PURPOSE: Given the financial hardships of surprise billing for patients, the aim of this study was to assess the degree to which radiologists effectively participate in commercial insurance networks by examining the trend in the share of radiologists' imaging claims that are out of network (OON). METHODS: A retrospective study over a 15-year period (2007-2021) was conducted using claims from Optum's deidentified Clinformatics Data Mart Database to assess the share of radiologists' imaging claims that are OON. Radiologists' annual OON rate was assessed overall as well as for claims associated with inpatient stays and emergency department (ED) visits. Rates were assessed for all imaging studies as well as by modality. Linear regression was conducted to assess OON rate time trends. RESULTS: From 2007 to 2021, 5,039,142 of radiologists' imaging claims (6.3%) were OON. This rate declined from 12.6% in 2007 to 1.1% in 2021. Over the study period, the OON rate was 5.0% during an inpatient stay and 2.1% on the same day as an ED visit that did not lead to an inpatient admission. The linear trend in the overall OON rate declined 0.74 percentage points annually (95% confidence interval [CI], -0.90 to -0.58 percentage points) over the study period. Likewise, the annual declines were 0.54 percentage points (95% CI, -0.71 to -0.36) and 0.26 percentage points (95% CI, -0.33 to -0.20 percentage points) for imaging claims associated with inpatient stays and ED visits, respectively. CONCLUSIONS: Radiologists' imaging claims that are OON has significantly declined from 2007 to a minimal level in 2021. This may indicate effective negotiations between radiologists and commercial payers and new state-level surprise billing laws.

The Neiman Imaging Comorbidity Index: Development and Validation in a National Commercial Claims Database.

OBJECTIVE: To build the Neiman Imaging Comorbidity Index (NICI), based on variables available in claims datasets, which provides good discrimination of an individual's chance of receiving advanced imaging (CT, MR, PET), and thus, utility as a control variable in research. METHODS: This retrospective study used national commercial claims data from Optum's deidentified Clinformatics Data Mart database from the period January 1, 2018 to December 31, 2019. Individuals with continuous enrollment during this 2-year study period were included. Lasso (least absolute shrinkage and selection operator) regression was used to predict the chance of receiving advanced imaging in 2019 based on the presence of comorbidities in 2018. A numerical index was created in a development cohort (70% of the total dataset) using weights assigned to each comorbidity, based on regression ß coefficients. Internal validation of assigned scores was performed in the remaining 30% of claims, with comparison to the commonly used Charlson Comorbidity Index. RESULTS: The final sample (development and validation cohorts) included 10,532,734 beneficiaries, of whom 2,116,348 (20.1%) received advanced imaging. After model development, the NICI included nine comorbidities. In the internal validation set, the NICI achieved good discrimination of receipt of advanced imaging with a C statistic of 0.709 (95% confidence interval [CI] 0.708-0.709), which predicted advanced imaging better than the CCI (C 0.692, 95% CI 0.691-0.692). Controlling for age and sex yielded better discrimination (C 0.748, 95% CI 0.748-0.749). DISCUSSION: The NICI is an easily calculated measure of comorbidity burden that can be used to adjust for patients' chances of receiving advanced imaging. Future work should explore external validation of the NICI.

Sociodemographic Factors and Screening CT Colonography Use Among Medicare Beneficiaries.

BACKGROUND. Approximately one-third of the eligible U.S. population have not undergone guideline-compliant colorectal cancer (CRC) screening. Guidelines recognize various screening strategies to increase adherence. CMS provides coverage for all recommended screening tests except CT colonography (CTC). OBJECTIVE. The purpose of this study was to compare CTC and other CRC screening tests in terms of associations of utilization with income, race and ethnicity, and urbanicity in Medicare fee-for-service beneficiaries. METHODS. This retrospective study used CMS Research Identifiable Files from January 1, 2011, through December 31, 2020. These files contain claims information for 5% of Medicare fee-for-service beneficiaries. Data were extracted for individuals 45-85 years old, and individuals with high CRC risk were excluded. Multivariable logistic regression models were constructed to determine the likelihood of undergoing CRC screening tests (as well as of undergoing diagnostic CTC, a CMS-covered test with similar physical access as screening CTC) as a function of income, race and ethnicity, and urbanicity while controlling for sex, age, Charlson comorbidity index, U.S. census region, screening year, and related conditions and procedures. RESULTS. For 12,273,363 beneficiary years (mean age, 70.5 ± 8.2 [SD] years; 2,436,849 unique beneficiaries: 6,774,837 female beneficiaries, 5,498,526 male beneficiaries), there were 785,103 CRC screenings events, including 645 for screening CTC. Compared with individuals living in communities with per capita income of less than US$25,000, individuals in communities with income of US$100,000 or more had OR for undergoing screening CTC of 5.73, optical colonoscopy (OC) of 1.36, sigmoidoscopy of 1.03, guaiac fecal occult blood test or fecal immunochemical test of 1.50, stool DNA of 1.43, and diagnostic CTC of 2.00. The OR for undergoing screening CTC was 1.00 for Hispanic individuals and 1.08 for non-Hispanic Black individuals compared with non-Hispanic White individuals. Compared with the OR for undergoing screening CTC for residents of metropolitan areas, the OR was 0.51 for residents of micropolitan areas and 0.65 for residents of small or rural areas. CONCLUSION. The association with income was substantially larger for screening CTC than for other CRC screening tests or for diagnostic CTC. CLINICAL IMPACT. Medicare's noncoverage for screening CTC may contribute to lower adherence with CRC screening guidelines for lower-income beneficiaries. Medicare coverage of CTC could reduce income-based disparities for individuals avoiding OC owing to invasiveness, need for anesthesia, or complication risk.

An exercise stress test for contrast-enhanced duplex ultrasound assessment of lower limb muscle perfusion in patients with peripheral arterial disease.

OBJECTIVE: The aim of the present study was to develop a standardized contrast-enhanced duplex ultrasound (CE-DUS) protocol to assess lower-extremity muscle perfusion before and after exercise and determine relationships of perfusion with clinical and functional measures. METHODS: CE-DUS (EPIQ 5G, Philips) was used before and immediately after a 10-minute, standardized bout of treadmill walking to compare microvascular perfusion of the gastrocnemius muscle in older (55-82 years) patients with peripheral arterial disease (PAD) (n = 15, mean ankle-brachial index, 0.78 ± 0.04) and controls (n = 13). Microvascular blood volume (MBV) and microvascular flow velocity (MFV) were measured at rest and immediately following treadmill exercise, and the Modified Physical Performance Test (MPPT) was used to assess mobility function. RESULTS: In the resting state (pre-exercise), MBV in patients with PAD was not significantly different than normal controls (5.17 ± 0.71 vs 6.20 ± 0.83 arbitrary units (AU) respectively; P = .36); however, after exercise, MBV was ∼40% lower in patients with PAD compared with normal controls (5.85 ± 1.13 vs 9.53 ± 1.31 AU, respectively; P = .04). Conversely, MFV was ∼60% higher in patients with PAD compared with normal controls after exercise (0.180 ± 0.016 vs 0.113 ± 0.018 AU, respectively; P = .01). There was a significant between-group difference in the exercise-induced changes in both MBV and MFV (P ≤ .05). Both basal and exercise MBV directly correlated with MPPT score in the patients with PAD (r = 0.56-0.62; P < .05). CONCLUSIONS: This standardized protocol for exercise stress testing of the lower extremities quantifies calf muscle perfusion and elicits perfusion deficits in patients with PAD. This technique objectively quantifies microvascular perfusion deficits that are related to reduced mobility function and could be used to assess therapeutic efficacy in patients with PAD.

Dual-energy X-ray Absorptiometry Trends Among US Medicare Beneficiaries: 2005-2019.

INTRODUCTION: Bone density measured using dual-energy X-ray absorptiometry (DXA) volume, performance site and interpreters have changed in the US since 2005. The purpose of this report is to provide updated trends in DXA counts, rates, place of service and interpreter specialty for the Medicare fee-for-service population. METHODS: The 100 % Medicare Physician/Supplier Procedure Summary Limited Data Set between 2005-2019 was used. DXA counts and annual rates per 10,000 Medicare beneficiaries were calculated. Annual distributions of scan performance location, provider type and interpreter specialty were described. Place of service trends (significance assigned at p < 0.05) of the mean annual share of DXA utilization were identified using linear regression. RESULTS: Annual DXA use per 10,000 beneficiaries peaked in 2008 at 832, declined to 656 in 2015 then increased (p < 0.001) by 38 per year to 807 in 2019. From 2005 to 2019 DXA performance in office settings declined from 70.7 % to 47.2 %. Concurrently, outpatient hospital (OH) DXA increased from 28.6 % to 51.7 %. In 2005, 43.5 % of DXAs were interpreted by radiologists. This increased (p < 0.001) in the office and OH, averaging 0.3 and 2.0 percentage points per year respectively, reaching 73.5 % in 2019. Interpretation by most non-radiologist specialties declined (p < 0.001). CONCLUSIONS: From 2005-2019, total DXA use among Medicare beneficiaries declined reaching a nadir in 2015 then returned to 2005 levels by 2019. Office DXA declined since 2005 with 51.7 % of all scans now occurring in an OH setting. The proportion of DXAs interpreted by radiologists increased over time, reaching 73.5 % in 2019.

Prevalence of "One-Off Events" in Radiology: Implications for Radiology in Episode-Based Alternative Payment Models.

OBJECTIVE: As reimbursement mechanisms become more value-based, there are questions about the applicability of these mechanisms for nonepisodic care, particularly care provided by nonpatient-facing specialists, for example, radiologists. Accordingly, this study examined the prevalence of nonepisodic care-one-off events-in diagnostic radiology. METHODS: We conducted a multiyear (2015-2019) retrospective study of diagnostic imaging using a large commercial payer database including commercial insurance and Medicare Advantage. Using a 12-month evaluation period starting with the day of the initial imaging study/studies, we categorized imaging studies as one-off events if there were no additional studies (beyond the first day of the evaluation period) for the next 12 months in the same body region. We also evaluated an alternative, more stringent definition of a one-off event: the only imaging study during the 12-month evaluation period. We computed the percentage of one-off events overall and by body region. RESULTS: We found that one-off events comprised 33.2%-45.8% of imaging studies depending on whether one-off events are defined as the only study in the evaluation period or imaging only on the first day of the evaluation period, respectively. This share varied widely by body region: highest for cardiac (80.9%-87.7%) and lower for chest (26.8%-35.2%). By place-of-service, the proportion was lowest for the inpatient (12.9%-29.1%) and long-term care settings (18.6%-30%). DISCUSSION: Given the sizeable share of imaging studies categorized as one-off events, much of radiologists' workload falls outside of the framework of episodic measurement tools and value-based payment models.

Budget Neutrality and Medicare Physician Fee Schedule Reimbursement Trends for Radiologists, 2005 to 2021.

PURPOSE: The Medicare program, by law, must remain budget neutral. Increases in volume or relative value units (RVUs) for individual services necessitate declines in either the conversion factor or assigned RVUs for other services for budget neutrality. This study aimed to assess the contribution of budget neutrality on reimbursement trends per Medicare fee-for-service beneficiary for services provided by radiologists. METHODS: The study used aggregated 100% of Medicare Part B claims from 2005 to 2021. We computed the percentage change in reimbursement per beneficiary, actual and inflation adjusted, to radiologists. These trends were then adjusted by separately holding constant RVUs per beneficiary and the conversion factor to demonstrate the impact of budget neutrality. RESULTS: Unadjusted reimbursement to radiologists per beneficiary increased 4.2% between 2005 and 2021, but when adjusted for inflation, it declined 24.9%. Over this period, the conversion factor declined 7.9%. Without this decline, the reimbursement per beneficiary would have been 9 percentage points higher in 2021 compared with actual. RVUs per beneficiary performed by radiologists increased 13.1%. Keeping RVUs per beneficiary at 2005 levels, reimbursement per beneficiary would have been 12.1 percentage points lower than observed in 2021. CONCLUSIONS: Given budget neutrality, a substantial decline has occurred in inflation-adjusted reimbursement to radiologists per Medicare beneficiary. Decreases due to both inflation and the decline in conversion factor are only partially offset by increased RVUs per beneficiary, meaning more services per patient with less overall pay, an equation likely to heighten access challenges for Medicare beneficiaries and shortages of radiologists.

Urbanicity, Income, and Mammography-Use Disparities Among American Indian Women.

INTRODUCTION: Reported breast cancer screening among American Indian women is consistently below that of White women. The last claims-based trends were from 1991 to 2001. This study updates mammography trends for American Indian women and examines the impact of race, urbanicity, and income on long-term mammography use. METHODS: This was a multi-year (2005-2019), retrospective study of women aged 40-89 years using a 5% sample of Medicare fee-for-service beneficiaries residing in Arizona, California, New Mexico, Oklahoma, and Washington. This study used multivariable logistic regression to examine the impact of urbanicity and income on receiving mammography for American Indian women compared with that for White women. Analyses were conducted in 2022. RESULTS: Overall, annual age-adjusted mammography use declined from 205 per 1,000 in 2005 to 165 per 1,000 in 2019. The slope of these declines was significantly steeper (difference = -2.41, p<0.001) for White women (-3.06) than for American Indian women (-0.65). Mammography-use odds across all urbanicity categories were less for American Indian women than for White women compared with those of their respective metropolitan counterparts (e.g., rural: 0.96, 95% CI=0.77, 1.20 for American Indian women and 1.47, 99% CI=1.39, 1.57 for White women). Although residing in higher-income communities was not associated with mammography use for American Indian women, it was 31% higher for White women (OR=1.31, 99% CI=1.28, 1.34). CONCLUSIONS: The disparity in annual age-adjusted mammography use between American Indian and White women narrowed between 2005 and 2019. However, the association of urbanicity and community income on mammography use differs substantially between American Indian and White women. Policies to reduce disparities need to consider these differences.

Relationship between Race and Access to Newer Mammographic Technology in Women with Medicare Insurance.

Background Racial disparities in breast cancer mortality have been reported. Mammographic technology has undergone two major technology transitions since 2000: first, the transition from screen-film mammography (SFM) to full-field digital mammography (FFDM) and second, the transition to digital breast tomosynthesis (DBT). Purpose To examine the relationship between use of newer mammographic technology and race in women receiving mammography services. Materials and Methods This was a multiyear (January 2005 to December 2020) retrospective study of women aged 40-89 years with Medicare fee-for-service insurance who underwent mammography. Data were obtained using a 5% research identifiable sample of all Medicare fee-for-service beneficiaries. Within-institution and comparable-institution use of mammographic technology between Black women or women of other races and White women were assessed with multivariable logistic and linear regression, respectively, adjusted for age, race, Charlson comorbidity index, per capita income, urbanicity, and institutional capability. Results Between 2005 and 2020, there were 4 028 696 institutional mammography claims for women (mean age, 72 years ± 8 [SD]). Within an institution, the odds ratio (OR) of Black women receiving digital mammography rather than SFM in 2005 was 0.80 (95% CI: 0.70, 0.91; P < .001) when compared with White women; these differences remained until 2009. Compared with White women, the use of DBT within an institution was less likely for Black women from 2015 to 2020 (OR, 0.84; 95% CI: 0.81, 0.87; P < .001). Across institutions, there were racial differences in digital mammography use, which followed a U-shaped pattern, and the differences peaked at 3.8 percentage points less for Black compared with White women (95% CI: -6.1, -1.6; P = .001) in 2011 and then decreased to 1.2 percentage points less (95% CI: -2.2, -0.2; P = .02) in 2016. Conclusion In the Medicare population, Black women had less access to new mammographic imaging technology compared with White women for both the transition from screen-film mammography to digital mammography and then for the transition to digital breast tomosynthesis. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Lee and Lawson in this issue.

Drivers of Ischemic Stroke Hospital Cost Trends Among Older Adults in the United States.

PURPOSE: The increased use of neuroimaging and innovations in ischemic stroke (IS) treatment have improved outcomes, but the impact on median hospital costs is not well understood. METHODS: A retrospective study was conducted using Medicare 5% claims data for 75,525 consecutive index IS hospitalizations for patients aged ≥65 years from 2012 to 2019 (values in 2019 dollars). IS episode cost was calculated in each year for trend analysis and stratified by cost components, including neuroimaging (CT angiography [CTA], CT perfusion [CTP], MRI, and MR angiography [MRA]), treatment (endovascular thrombectomy [EVT] and/or intravenous thrombolysis), and patient sociodemographic factors. Logistic regression was performed to analyze the drivers of high-cost episodes and median regression to assess drivers of median costs. RESULTS: The median IS episode cost increased by 4.9% from $9,509 in 2012 to $9,973 in 2019 (P = .0021). Treatment with EVT resulted in the greatest odds of having a high-cost (>$20,000) hospitalization (odds ratio [OR], 71.86; 95% confidence interval [CI], 54.62-94.55), as did intravenous thrombolysis treatment (OR, 3.19; 95% CI, 2.90-3.52). Controlling for other factors, neuroimaging with CTA (OR, 1.72; 95% CI, 1.58-1.87), CTP (OR, 1.32; 95% CI, 1.14-1.52), and/or MRA (OR, 1.26; 95% CI, 1.15-1.38) had greater odds of having high-cost episodes than those without CTA, CTP, and MRA. Length of stay > 4 days (OR, 4.34; 95% CI, 3.99-4.72) and in-hospital mortality (OR, 1.85; 95% CI, 1.63-2.10) were also associated with high-cost episodes. CONCLUSIONS: From 2012 to 2019, the median IS episode cost increased by 4.9%, with EVT as the main cost driver. However, the increasing treatment cost trends have been partially offset by decreases in median length of stay and in-hospital mortality.

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.

Effects of Hospital Practice Patterns for Antibiotic Administration for Pneumonia on Hospital Lengths of Stay and Costs.

BACKGROUND: Hospital practice patterns vary for switching from intravenous to oral antibiotics for community-acquired pneumonia in pediatric patients, but it is unknown how these practice patterns affect hospital lengths of stay and costs. METHODS: We conducted a retrospective study of 78673 pediatric patients (aged 3 months to 17 years) hospitalized for community-acquired pneumonia. Analyses were performed with data from the Pediatric Health Information System between 2007 and 2016, including discharge data from 48 freestanding children's hospitals. Patients who received antibiotics used to treat aspiration pneumonia and patients with a complex chronic condition were excluded to focus the study on uncomplicated cases. We modeled hospital practice patterns using hospital-level averages for the last day of service on which patients received antibiotics intravenously or first day of service on which patients received antibiotics orally. RESULTS: We found that a 1-day decrease in the hospital-level average last day of service on which a patient received antibiotics intravenously reduced the average length of stay by 0.58 day (95% confidence interval [CI], -0.69 to -0.47 day) and average cost by $1332 (95% CI, -$2363 to -$300). Results were similar when hospital practice patterns were modeled using the average first day of service on which a patient received antibiotics orally. These reductions in lengths of stay and costs were not associated with a difference in 30-day readmission rates. CONCLUSIONS: Given the reductions in lengths of stay and costs without sacrificing patient outcomes (readmissions), antimicrobial stewardship programs could target provider education on the duration of intravenous antibiotic therapy as a way to reduce resource utilization.

Trends in Medical Claims and Utilization of Limited Ultrasonography Among Emergency Physicians and Radiologists Within a Large Health Plan Provider.

OBJECTIVES: The goal of this study was to evaluate trends in medical claim submissions for limited ultrasound studies performed (1) during emergency department (ED) encounters and (2) by ED providers compared to radiologists. METHODS: We conducted a retrospective, descriptive study using medical claims data from Medica Health Plans from January 1, 2011 to December 31, 2015. Current procedural terminology codes were abstracted for limited ultrasound applications performed during an ED visit and further stratified by studies performed by ED providers compared with radiologists. We excluded claims for which we could not determine provider specialty. RESULTS: We identified 42,576 encounters with limited US claims, of which, 32,666 were submitted by ED providers (N = 9649) or radiologists (N = 23,017). Among ED providers, there was a significant linear increase in the annual number of claims for retroperitoneal (P < .001) and nonlinear increases for thoracic, soft tissue, cardiac, transvaginal genitourinary (GU) and transabdominal GU claims (all P < .001). Compared with radiologists, there was a linear increase in the annual proportion of claims submitted for retroperitoneal (P = .023), transabdominal GU (P = .003), and transvaginal GU (P < .001) studies by ED providers. There was a nonlinear decrease in the annual proportion of limited abdomen claims (P < .001) submitted by ED providers compared with radiologists. CONCLUSIONS: Using data from a large health plan provider, we show that medical claims for many limited ultrasound studies are increasing among ED providers. Compared with radiologists, ED providers are increasingly submitting claims for retroperitoneal, soft tissue, and transabdominal GU studies.

Economic Analysis of Diagnostic Imaging in Pediatric Patients With Suspected Appendicitis.

OBJECTIVE: The use of computed tomography (CT) and ultrasound (US) in patients with acute abdominal pain has substantial variation across pediatric emergency departments (EDs). This study compares the cost of diagnosing and treating suspected appendicitis across a multicenter network of children's hospitals. METHODS: This study is a secondary analysis using deidentified data of a prospective, observational study of patients with suspected appendicitis at nine pediatric EDs. The study included patients 3 to 18 years old who presented to the ED with acute abdominal pain of <96 hours' duration. RESULTS: Our data set contained 2,300 cases across nine sites. There was an appendicitis rate of 31.8% and perforation rate of 25.7%. Sites correctly diagnosed appendicitis in over 95% of cases. The negative appendicitis rate ranged from 2.5% to 4.7% while the missed appendicitis rate ranged from 0.3% to 1.1% with no significant differences in these rates across site. Across sites, we found a strong positive correlation (0.95) between CT rate and total cost per case and a strong negative correlation (-0.71) between US rate and cost. The cost per case at US sites was 5.2% ($367) less than at CT sites (p < 0.001). Similarly, costs per case at mixed sites were 3.4% ($244) less than at CT sites (p < 0.001). Comparing costs among CT sites or among US sites, the cost per case generally increased as the images per case increased among both CT sites and US sites, but the costs were universally higher at CT sites. CONCLUSIONS: Our results provide support for US as the primary imaging modality for appendicitis. Sites that preferentially utilized US had lower costs per case than sites that primarily used CT. Imaging rates across sites varied due to practice patterns and resulted in a significant cost consequence without higher rates for negative appendectomies or missed appendicitis cases.

Predicting Frequent Emergency Department Use by Pediatric Medicaid Patients.

The objective of this study was to determine the patient characteristics and health care utilization patterns that predict frequent emergency department (ED) use (≥4 visits per year) over time to assist health care organizations in targeting patients for care management. This was a retrospective, population-based study of 13,265 Medicaid children aged 0-20 years who were attributed to a single pediatric accountable care organization for at least 2 consecutive years between June 2012 and May 2015. Year-to-year persistence as a frequent ED user was 36.3% (95% confidence interval [CI]: 33.4 to 38.4), which does not support the notion that once a frequent user, always a frequent user. Hence, interventions to reduce frequent ED use may appear to be effective when ED use would have regressed toward the mean without any intervention. At an individual patient level, predictability of frequent ED use was 0.437 (95% CI: 0.358 to 0.485) across frequent ED users of all ages compared with 0.723 (95% CI: 0.435 to 0.824) for those aged <1 year. Accordingly, this latter group may be a better target for interventions than frequent ED users generally.