A Claims-Based Method for Identification and Characterization of Practicing Interventional Radiologists.

PURPOSE: To propose a research method for identifying "practicing interventional radiologists" using 2 national claims data sets. MATERIALS AND METHODS: The 2015-2019 100% Medicare Part B data and 2015-2019 private insurance claims from Optum's Clinformatics Data Mart (CDM) database were used to rank-order radiologists' interventional radiology (IR)-related work as a percentage of total billed work relative value units (RVUs). Characteristics were analyzed at various threshold percentages. External validation used Medicare self-designated specialty with Society of Interventional Radiology (SIR) membership records; Youden index evaluated sensitivity and specificity. Multivariate logistic regression assessed practicing IR characteristics. RESULTS: In the Medicare data, above a 10% IR-related work threshold, only 23.8% of selected practicing interventional radiologists were designated as interventional radiologists; above 50% and 90% thresholds, this percentage increased to 42.0% and 47.5%, respectively. The mean percentage of IR-related work among practicing interventional radiologists was 45%, 84%, and 96% of total work RVUs for the 10%, 50%, and 90% thresholds, respectively. At these thresholds, the CDM practicing interventional radiologists included 21.2%, 35.2%, and 38.4% designated interventional radiologists, and evaluation and management services comprised relatively more total work RVUs. Practicing interventional radiologists were more likely to be males, metropolitan, and earlier in their careers than other radiologists at all thresholds. CONCLUSIONS: Most radiologists performing IR-related work are designated in claims data as diagnostic radiologists, indicating insufficiency of specialty designation for IR identification. The proposed method to identify practicing interventional radiologists by percent IR-related work effort could improve generalizability and comparability across claims-based IR studies.

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. The purpose of the present study was 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. Based on the specialty mix of all affiliated physicians, practices were categorized 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 radiologists enrolled in Medicare increased 17.3% (from 30,723 to 36,024), whereas the number of affiliated practices decreased 14.7% (from 5059 to 4313). The number of radiology-only, radiology-majority, other-specialty-majority, and no-majority-specialty practices changed by -31.8% (from 3104 to 2118), 10.9% (from 402 to 446), -5.7% (from 615 to 580), and 24.6% (from 938 to 1169), respectively. The number of practices with one to two, three to nine, 10-24, 25-49, 50-99, and 100 or more radiologists changed by -18.7% (from 2233 to 1815), -34.4% (from 1406 to 923), -25.2% (from 910 to 681), 33.2% (from 352 to 469), 121.6% (from 125 to 277), and 348.5% (from 33 to 148). A total of 3494 practices ceased, including 2281 radiology-only practices. Among 3854 radiologists whose 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. CONCLUSION. 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. Although determining the causes of consolidation was beyond this scope of this study, the shifts may relate to economic incentives and legislative changes favoring large multispecialty practices. CLINICAL IMPACT. The continued consolidation of radiologists into large multispecialty practices may facilitate subspecialization and greater negotiating power in payer contracting. However, radiologists may prefer smaller and/or radiology-only practices for reasons of autonomy and influence on practice structure.

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.

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.

Ten-year trends, disparities, and clinical impact of stroke thrombectomy and thrombolysis: A single center experience 2012-2021.

OBJECTIVES: As indications for acute ischemic stroke treatment expand, it is unclear whether disparities in treatment utilization and outcome still exist. The main objective of this study was to investigate disparities in acute ischemic stroke treatment and determine impact on outcome. MATERIALS AND METHODS: Retrospective observational cohort study of consecutive ischemic stroke admissions to a comprehensive stroke center from 2012-2021 was performed. Primary exposure was intravenous thrombolysis and/or endovascular thrombectomy. Primary end points were discharge modified Rankin Scale, home disposition, and expired/hospice. Multivariable logistic regression analyses were conducted to elucidate disparities in treatment utilization and determine impact on outcome. RESULTS: Of 517,615 inpatient visits, there were 7,540 (1.46 %) ischemic stroke admissions, increasing from 1.14 % to 1.79 % from 2012-2021. Intravenous thrombolysis significantly decreased from 14.4 % to 9.8 % while endovascular thrombectomy significantly increased from 0.8 % to 10.5 %. Both intravenous thrombolysis and endovascular thrombectomy increased odds of discharge home and modified Rankin Scale 0-2, and thrombectomy decreased odds of expired/hospice. After adjusting for covariates, decreased odds of thrombectomy was associated with Medicaid insurance (Odds Ratio [95 % Confidence Interval] 0.55 [0.32-0.93]), age 80+ (0.49 [0.35-0.69]), prior stroke (0.49 [0.31-0.77]), and diabetes mellitus (0.55 [0.39-0.79]), while low median household income (<$80,000/year) increased odds of no acute treatment (1.34 [1.16-1.56]). No sex or racial disparities were observed. Medicaid and low-income were not associated with worse clinical outcomes. CONCLUSIONS: Less endovascular thrombectomy occurred in Medicaid, older, prior stroke, and diabetic patients, while low-income was associated with no treatment. The observed socioeconomic disparities did not impact discharge outcome.

Time-driven activity-based costing (TDABC) of direct-to-angiography pathway for acute ischemic stroke patients with suspected large vessel occlusion.

INTRODUCTION: Direct-to-angiography (DTA) is a novel care pathway for endovascular treatment (EVT) of acute ischemic stroke (AIS) that has been shown to reduce time-to-treatment and improve clinical outcomes for EVT-eligible patients. The institutional costs of adopting the DTA pathway and the many factors affecting costs have not been studied. In this study, we assess the costs and main cost drivers associated with the DTA pathway compared to the conventional CT pathway for patients presenting with AIS and suspected LVO in the anterior circulation. METHODS: Time driven activity based costing (TDABC) model was used to compare costs of DTA and conventional pathways from the healthcare institution perspective. Process mapping was used to outline all activities and resources (personnel, equipment, materials) needed for each step in both pathways. The cost model was developed using our institutional patient database and average New York state wages for personnel costs. Total, incremental and proportional costs were calculated based on institutional and patient factors affecting the pathways. RESULTS: DTA pathway accrued additional $82,583.61 (9%) in total costs compared to the conventional approach for all AIS patients. For EVT-ineligible patients, the DTA pathway incurred additional $82,964.37 (76%) in total costs compared to the CT pathway. For EVT eligible patients, the total and per-patient costs were greater in the CT pathway by $380.76 (0.04%) and $5.60 (0.04%) respectively. CONCLUSION: As the DTA pathway incurred additional $82,964.37 for EVT-ineligible patients, appropriate patient selection criteria are needed to avoid transferring EVT-ineligible patients to the angiography suite.

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.

Radiologists' 2021 Quality Reporting and Performance in Medicare's Merit-Based Incentive Payment System: Analysis by Practice Type.

This study of national CMS data shows differences in quality reporting and performance of Merit-Based Incentive Payment System (MIPS)-participating radiologists by practice specialty mix. For certain practice types, radiologist-reported quality measures were commonly not radiology measures. The results support a need to expand radiology measures and to better align measure reporting with clinician specialty.

Increasing exercise frequency is associated with health and quality-of-life benefits for older adults.

PURPOSE: To evaluate whether health-related quality-of-life measures can be improved in a senior population by increasing participation in an exercise program. METHODS: The study involved a nationwide sample of adults aged 65 and older (mean age 73.2 in first study year) who participated in the SilverSneakers fitness program between 2010 and 2016. We analyzed data from 7 years of program participation records and annual participant surveys. Study members completed ≥ 2 annual surveys (n = 46,564). Participation frequency change was measured by average visits per week (AVPW) to a fitness center from the initial survey year to follow-up years. Quality-of-life measures included the 12-Item Short Form Health Survey (SF-12), Self-Rated Health, and BRFSS Healthy Days measures. Longitudinal analyses evaluated whether an increase in visit frequency among active members of SilverSneakers was associated with change in quality-of-life measures, controlling for age and gender. RESULTS: Participants with more frequent visits (higher AVPW) had better SF-12 Physical and Mental Component Scores, Self-Rated Health Status, and fewer physically and mentally unhealthy days (p < 0.001 for all measures); furthermore, participants who increased AVPW longitudinally saw improvements in all outcome measures (p < 0.001). CONCLUSION: SilverSneakers participation frequency is associated with higher quality of life for seniors.

Effect of post-hospital discharge telephonic intervention on hospital readmissions in a privately insured population in Australia.

Objective The aim of the present study was to evaluate the effect of telephone support after hospital discharge to reduce early hospital readmission among members of the disease management program My Health Guardian (MHG) offered by the Hospitals Contribution Fund of Australia (HCF). Methods A quasi-experimental retrospective design compared 28-day readmissions of patients with chronic disease between two groups: (1) a treatment group, consisting of MHG program members who participated in a hospital discharge (HODI) call; and (2) a comparison group of non-participating MHG members. Study groups were matched for age, gender, length of stay, index admission diagnoses and prior MHG program exposure. Adjusted incidence rate ratios (IRR) and odds ratios (OR) were estimated using zero-inflated negative binomial and logistic regression models respectively. Results The treatment group exhibited a 29% lower incidence of 28-day readmissions than the comparison group (adjusted IRR 0.71; 95% confidence interval (CI) 0.59-0.86). The odds of treatment group members being readmitted at least once within 28 days of discharge were 25% lower than the odds for comparison members (adjusted OR 0.75; 95% CI 0.63-0.89). Reduction in readmission incidence was estimated to avoid A$713730 in cost. Conclusions The HODI program post-discharge telephonic support to patients recently discharged from a hospital effectively reduced the incidence and odds of hospital 28-day readmission in a diseased population. What is known about the topic? High readmission rates are a recognised problem in Australia and contribute to the over 600000 potentially preventable hospitalisations per year. What does this paper add? The present study is the first study of a scalable intervention delivered to an Australian population with a wide variety of conditions for the purpose of reducing readmissions. The intervention reduced 28-day readmission incidence by 29%. What are the implications for practitioners? The significant and sizable effect of the intervention support the delivery of telephonic support after hospital discharge as a scalable approach to reduce readmissions.

Long-term impact of a chronic disease management program on hospital utilization and cost in an Australian population with heart disease or diabetes.

BACKGROUND: To evaluate the longitudinal value of a chronic disease management program, My Health Guardian (MHG), in reducing hospital utilization and costs over 4 years. METHODS: The MHG program provides individualized support via telephonic nurse outreach and online tools for self-management, behavior change and well-being. In follow up to an initial 18-month analysis of MHG, the current study evaluated program impact over 4 years. A matched-cohort analysis retrospectively compared MHG participants with heart disease or diabetes (treatment, N = 4,948) to non-participants (comparison, N = 28,520) on utilization rates (hospital admission, readmission, total bed days) and hospital claims cost savings. Outcomes were evaluated using regression analyses, controlling for remaining demographic, disease, and pre-program admissions or cost differences between the study groups. RESULTS: Over the 4 year period, program participation resulted in significant reductions in hospital admissions (-11.4%, P < 0.0001), readmissions (-36.7%, P < 0.0001), and bed days (-17.2%, P < 0.0001). The effect size increased over time for admissions and bed days. The relative odds of any admission and readmission over the 4 years were 27% and 45% lower, respectively, in the treatment group. Cumulative program savings from reduced hospital claims was $3,549 over 4-years; savings values for each program year were significant and increased with time (P = 0.003 to P < 0.0001). Savings calculations did not adjust for pooled costs (and savings) in Australia's risk equalization system for private insurers. CONCLUSIONS: Results confirm and extend prior program outcomes and support the longitudinal value of the MHG program in reducing hospital utilization and costs for individuals with heart disease or diabetes and demonstrate the increasing program effect with continued participation over time.

Share of Diagnostic Imaging Interpretation: Radiology and Other Specialties.

PURPOSE: The aim of this study was to examine radiology's and other specialties' market shares for diagnostic imaging interpretation for Medicare fee-for-service claims by modality, body region, and place of service. METHODS: In this cross-sectional study of Physician/Supplier Procedure Summary data for 2022, the authors examined the proportion of diagnostic imaging interpretation by specialty. All claims for CT, MR, nuclear medicine (NM), ultrasound, and radiography and fluoroscopy (XR) were included. Claims were aggregated into 52 specialty groups using Medicare specialty codes. The market share for each specialty group was computed by modality, body region, and place of service. RESULTS: For Medicare fee-for-service beneficiaries, there were 122,851,716 imaging studies, of which 88,559,272 (72.1%) were interpreted by radiologists. This percentage varied by modality: 97.3% for CT, 91.0% for MR, 76.6% for XR, 50.9% for NM, and 33.9% for ultrasound. Radiologists interpreted a lower percentage of cardiac (67.6% for CT, 42.2% for MR, 11.8% for NM, and 0.4% for ultrasound) than noncardiac studies (97.6% for CT, 91.4% for MR, 95.6% for NM, and 53.0% for ultrasound). Among noncardiac studies, radiologists interpreted nearly all in the outpatient hospital, inpatient, and emergency department (99.5% for CT, 99.4% for MR, 98.9% for NM, 79.3% for ultrasound, and 97.9% for XR) compared with the office setting (84.4% for CT, 78.7% for MR, 85.4% for NM, 29.2% for ultrasound, and 43.1% for XR). CONCLUSIONS: Radiologists perform the dominant share of CT and MR interpretation and more so for noncardiac imaging and imaging performed in outpatient hospital, inpatient, and emergency department places of service.

Decomposition of medical imaging spending growth between 2010 and 2021 in the US employer-insured population.

Medical imaging, identified as a potential driver of unsustainable US health care spending growth, was subject to policies to reduce prices and use in low-value settings. Meanwhile, the Affordable Care Act increased access to preventive services-many involving imaging-for employer-sponsored insurance (ESI) beneficiaries. We used a large insurance claims database to examine imaging spending trends in the ESI population between 2010 and 2021-a period of considerable policy and benefits changes. Nominal spending on imaging increased 35.9% between 2010 and 2021, but as a share of total health care spending fell from 10.5% to 8.9%. The 22.5% growth of nominal imaging prices was below inflation, 24.3%, as measured by the Consumer Price Index. Other key contributors to imaging spending growth were increased use (7.4 percentage points [pp]), shifts toward advanced modalities (4.0 pp), and demographic changes (3.5 pp). Shifts in care settings and provider network participation resulted in 2.5-pp and 0.3-pp imaging spending decreases, respectively. In sum, imaging spending decreased as a share of all health care spending and relative to inflation, as intended by concurrent cost-containment policies.

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.

Gender-Based Disparity in Acute Stroke Imaging Utilization and the Impact on Treatment and Outcomes: 2012 to 2021.

INTRODUCTION: Prior studies have revealed significant socio-economic disparities in neuro-imaging and treatment utilization for patients with acute ischemic stroke (AIS). In this study, we sought to evaluate whether a sex-based disparity exists in neuro-imaging and to determine its etiology and association with acute treatment and outcomes. MATERIALS AND METHODS: This was a retrospective study of consecutive patients with AIS admitted to a comprehensive stroke center between 2012 and 2021. Patient demographic and clinical characteristics, neuro-imaging, acute treatment, and early clinical outcomes were extracted from the electronic medical records. Trend analysis, bivariate analysis of patient characteristics by sex, and multivariable logistic regression analyses were conducted. RESULTS: Of the 7,540 AIS episodes registered from 2012 to 2021, 47.9% were female patients. After adjusting for demographic, clinical, and temporal factors, significantly higher utilization of CTA was found for male patients (odds ratio = 1.20 [95% confidence interval 1.07-1.34]), particularly from socio-economically advantaged groups, and in years 2015 and 2019, representing the years endovascular thrombectomy recommendations changed. Despite this, male patients had significantly lower intravenous thrombolysis utilization (odds ratio = 0.83 [95% confidence interval 0.71-0.96]) and similar endovascular thrombectomy rates as female patients. There were no significant sex differences in early clinical outcomes, and no relevant clinical or demographic factors explained the CT angiography utilization disparity. CONCLUSION: Despite higher CT angiography utilization in socio-economically advantaged male patients with AIS, likely overutilization due to implicit biases following guideline updates, the rates of acute treatment, and early clinical outcomes were unaffected.

Projected Growth in FDA-Approved Artificial Intelligence Products Given Venture Capital Funding.

PURPOSE: Medical imaging accounts for 85% of digital health's venture capital funding. As funding grows, it is expected that artificial intelligence (AI) products will increase commensurately. The study's objective is to project the number of new AI products given the statistical association between historical funding and FDA-approved AI products. METHODS: The study used data from the ACR Data Science Institute and for the number of FDA-approved AI products (2008-2022) and data from Rock Health for AI funding (2013-2022). Employing a 6-year lag between funding and product approved, we used linear regression to estimate the association between new products approved in a certain year, based on the lagged funding (ie, product-year funding). Using this statistical relationship, we forecasted the number of new FDA-approved products. RESULTS: The results show that there are 11.33 (95% confidence interval: 7.03-15.64) new AI products for every $1 billion in funding assuming a 6-year lag between funding and product approval. In 2022 there were 69 new FDA-approved products associated with $4.8 billion in funding. In 2035, product-year funding is projected to reach $30.8 billion, resulting in 350 new products that year. CONCLUSIONS: FDA-approved AI products are expected to grow from 69 in 2022 to 350 in 2035 given the expected funding growth in the coming years. AI is likely to change the practice of diagnostic radiology as new products are developed and integrated into practice. As more AI products are integrated, it may incentivize increased investment for future AI products.

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.

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.

Association between Heat Vulnerability Index and Stroke Severity.

BACKGROUND: Socioeconomically disadvantaged neighborhoods are particularly vulnerable to heat-related illnesses. We aim to investigate the association between the heat vulnerability index (HVI), an established neighborhood-level metric of heat-related mortality risk, and acute ischemic stroke (AIS) severity. METHODS: We conducted a retrospective analysis of consecutive AIS admissions to a comprehensive stroke center between 2012 and 2021. Stroke severity was defined upon admission based on the National Institutes of Health Stroke Scale (NIHSS). Demographic, socioeconomic, and clinical characteristics were extracted from electronic health records. HVI status was assigned using residential ZIP codes. Multivariable logistic regression analyses were performed. RESULTS: Of 3429 AIS admissions, 1123 (32.8%) were from high-HVI (scores 4-5) neighborhoods and 868 (25.3%) had severe stroke (NIHSS score ≥ 10). In the multivariable regression model with stepwise selection, a high HVI was independently associated with severe stroke (adjusted odds ratio: 1.40 [95% confidence interval 1.16-1.69]). CONCLUSIONS: The association between a high HVI and severe stroke underscores the importance of targeting policy interventions to mitigate heat-related illness in socioeconomically disadvantaged neighborhoods.

Differential Access to Breast Magnetic Resonance Imaging Compared with Mammography and Ultrasound.

INTRODUCTION: For high-risk women, breast magnetic resonance (MR) is the preferred supplemental imaging option, but spatial access differences may exacerbate disparities in breast care. METHODS: This was a cross-sectional study examining distance between ZIP codes and the nearest breast imaging facility (MR, mammography, ultrasound) using 2023 data from the Food and Drug Administration and the American College of Radiology. Linear regression was used to assess distance differences controlling for Area Deprivation Index (ADI), urbanicity, and population size. Analyses were conducted in 2024. RESULTS: Among the 29,629 ZIP codes with an ADI and known urbanicity, unadjusted mean distance to breast MR was 23.2±25.1 miles (SD) compared with 8.2±8.3 for mammography and 22.2±25.0 for ultrasound. Hence, the average distance to breast MR facilities was 2.8 times further than to mammography facilities. ADI and urbanicity were associated with increased distance to the nearest breast imaging facility. The additional miles associated with the least advantaged areas compared with most advantaged areas was 12.2 (95%CI: 11.3, 13.2) for MR, 11.5 miles (95%CI: 10.6, 12.3) for ultrasound, and 2.4 (95%CI: 2.1, 2.7) for mammography. Compared with metropolitan areas, the additional miles to breast MR facilities was 23.2 (95%CI: 22.5, 24.0) for small/rural areas. CONCLUSIONS: Spatial access is substantially better for mammography sites compared with breast MR or ultrasound sites. Given these findings, consideration of options to mitigate the impact of differential access should be considered. For example, mammography sites could offer contrast-enhanced mammography. Future research should examine the feasibility and effectiveness of this and other options.