Utilization of Chest and Abdominopelvic CT for Traumatic Injury From 2011 to 2018: Evaluation Using a National Commercial Database.

BACKGROUND. Increases in the use of CT to evaluate patients presenting with trauma have raised concern about inappropriate imaging. The evolving utilization of CT for trauma evaluation may be impacted by injury severity. OBJECTIVE. The purpose of this study was to explore patterns in utilization of chest and abdominopelvic CT among trauma-related emergency department (ED) visits across the United States. METHODS. This retrospective study was conducted with national commercial claims information extracted from the MarketScan Commercial Database. Trauma-related ED encounters were identified from the 2011-2018 MarketScan database files and classified by injury severity score (minor, intermediate, and major injuries) on the basis of International Classification of Diseases codes. ED encounters were also assessed for chest CT, abdominopelvic CT, and single-encounter chest and abdominopelvic CT examinations. Utilization per 1000 trauma-related ED encounters was determined. Multivariable Poisson regression models were used to determine incidence rate ratios (IRRs) as a measure of temporal changes in utilization. RESULTS. From 2011 to 2018, 8,369,092 trauma-related ED encounters were identified (5,685,295 for minor, 2,624,944 for intermediate, and 58,853 for major injuries). Utilization of chest CT per 1000 trauma-related ED encounters increased from 4.9 to 13.5 examinations (adjusted IRR, 1.15 per year; minor injuries, from 2.2 to 7.7 [adjusted IRR, 1.17]; intermediate injuries, from 8.5 to 21.5 [adjusted IRR, 1.16]; major injuries, from 117.8 to 200.1 [adjusted IRR, 1.08]). Utilization of abdominopelvic CT per 1000 trauma-related ED encounters increased from 7.5 to 16.4 (adjusted IRR, 1.12; minor injuries, 4.8 to 12.2 [adjusted IRR, 1.13]; intermediate injuries, 10.6 to 21.7 [adjusted IRR, 1.13]; major injuries, 134.8 to 192.6 [adjusted IRR, 1.07]). Utilization of single-encounter chest and abdominopelvic CT per 1000 trauma-related ED encounters increased from 3.4 to 8.9 [adjusted IRR, 1.16; minor injuries, 1.1 to 4.6 [adjusted IRR, 1.18]; intermediate injuries, 6.4 to 16.4 [adjusted IRR, 1.16]; major injuries, 99.6 to 179.9 [adjusted IRR, 1.08]). CONCLUSION. National utilization of chest and abdominopelvic CT for trauma-related ED encounters increased among commercially insured patients from 2011 to 2018, particularly for single-encounter chest and abdominopelvic CT examinations and for minor injuries. CLINICAL IMPACT. Given concerns about increased cost and detection of incidental findings, further investigation is warranted to explore the potential benefit of single-encounter chest and abdominopelvic CT examinations of patients with minor injuries and to develop strategies for optimizing appropriateness of imaging orders.

Increasing Utilization of Emergency Department Neuroimaging From 2007 Through 2017.

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

Defining the Value of Interventional Radiology to Healthcare Stakeholders: Proceedings from a Society of Interventional Radiology Research Consensus Panel.

Interventional radiology (IR) has collectively struggled to articulate and prove its value to several external stakeholders. The goal of this research consensus panel was to provide a summary of the existing knowledge, identify current gaps in knowledge, identify the strengths and weaknesses in existing data, and prioritize research needs related to the value of IR. Panelists were asked to identify the critical relationships/alliances that should be fostered to advance the prioritized research and determine how the Society of Interventional Radiology and the Society of Interventional Radiology Foundation can further support these initiatives. Following presentations and discussions, it was determined that proving and quantifying how IR decreases the length of stay and prevents hospital admissions are the most salient, value-related research topics to pursue for the specialty.

Disparities in the Use of Emergency Department Advanced Imaging in Medicare Beneficiaries.

OBJECTIVE. The purpose of our study was to assess potential disparities in the utilization of advanced imaging during emergency department (ED) visits. MATERIALS AND METHODS. This retrospective study was conducting using 5% Research Identifiable Files. All CT and MRI (together defined as "advanced imaging") examinations associated with ED visits in 2015 were identified for continuously enrolled Medicare beneficiaries. Individuals with medical claims 30 days before the index ED event were excluded, and encounters that occurred in hospitals without advanced imaging capabilities were also excluded. Patient characteristics were identified using Medicare files and hospital characteristics using the American Hospital Association Annual Survey of Hospitals. Multivariate logistic regression was used for the analysis. RESULTS. Of 86,976 qualifying ED encounters, 52,833 (60.74%) ED encounters were for female patients; 29.03% (n = 25,245) occurred at rural hospitals and 15.81% (n = 13,750) at critical access hospitals. Race distribution was 83.13% White, 11.05% Black, and 5.82% Other. Compared with ED patients at urban hospitals, those at rural and critical access hospitals were 6.9% less likely (odds ratio [OR] = 0.931, p = 0.015) and 18.0% less likely (OR = 0.820, p < 0.0001), respectively, to undergo advanced imaging. Compared with White patients, Black patients were 31.6% less likely (OR = 0.684, p < 0.0001) to undergo advanced imaging. Relative to their urban counterparts, both White (OR = 0.941, p = 0.05) and Black (OR = 0.808, p = 0.047) rural ED patients were less likely to undergo advanced imaging. CONCLUSION. Among Medicare beneficiaries receiving care in U.S. EDs, significant disparities exist in advanced imaging utilization. Although imaging appropriateness was not investigated, these findings suggest inequity. Further research is necessary to understand why consistent health benefits do not translate into consistent imaging access among risk-adjusted ED patients.

How hospitals can improve their public quality metrics: a decision-theoretic model.

The public reporting of hospitals' quality of care is providing additional motivation for hospitals to deliver high-quality patient care. Hospital Compare, a consumer-oriented website by the Centers for Medicare and Medicaid Services (CMS), provides patients with detailed quality of care data on most US hospitals. Given that many quality metrics are the aggregate result of physicians' individual clinical decisions, the question arises if and how hospitals could influence their physicians so that their decisions positively contribute to hospitals' quality goals. In this paper, we develop a decision-theoretic model to explore how three different hospital interventions-incentivization, training, and nudging-may affect physicians' decisions. We focus our analysis on Outpatient Measure 14 (OP-14), which is an imaging quality metric that reports the percentage of outpatients with a brain computed tomography (CT) scan, who also received a same-day sinus CT scan. In most cases, same-day brain and sinus CT scans are considered unnecessary, and high utilizing hospitals aim to reduce their OP-14 metric. Our model captures the physicians' imaging decision process accounting for medical and behavioral factors, in particular the uncertainty in clinical assessment and a physician's diagnostic ability. Our analysis shows how hospital interventions of incentivization, training, and nudging affect physician decisions and consequently OP-14. This decision-theoretic model provides a foundation to develop insights for policy makers on the multi-level effects of their policy decisions.

CT Angiography for Triage of Patients with Acute Minor Stroke: A Cost-effectiveness Analysis.

Background Minor stroke is common and may represent up to two-thirds of cases of acute ischemic stroke. The cost-effectiveness of CT angiography in patients with minor stroke (National Institutes of Health Stroke Scale [NIHSS] score ≤6) is not well established. Purpose To evaluate cost-effectiveness of CT angiography in the detection of large-vessel occlusion (LVO) in patients with acute minor stroke (NIHSS score ≤6). Materials and Methods A Markov decision-analytic model with a societal perspective was constructed. Three different management strategies were evaluated: (a) no vascular imaging and best medical management, (b) CT angiography for all patients and immediate thrombectomy for LVO after intravenous thrombolysis, and (c) CT angiography for all and best medical management (including intravenous thrombolysis, with rescue thrombectomy for patients with LVO and neurologic deterioration). One-way, two-way, and probabilistic sensitivity analyses were performed. Results Base-case calculation showed that CT angiography followed by immediate thrombectomy had the lowest cost ($346 007) and highest health benefits (9.26 quality-adjusted life-years [QALYs]). CT angiography followed by best medical management with possible rescue thrombectomy for patients with LVO had a slightly higher cost ($346 500) and lower health benefits (9.09 QALYs). No vascular imaging had the highest cost and lowest health benefits. The difference in health benefits compared with the CT angiography and immediate thrombectomy strategy was 0.39 QALY, which corresponds to 142 days in perfect health per patient. The conclusion was robust in a probabilistic sensitivity analysis. CT angiography was cost-effective when the probability of LVO was greater than 0.16% in patients with acute minor stroke. The net monetary benefit of performing CT angiography was higher in younger patients ($68 950 difference between CT angiography followed by immediate thrombectomy and no vascular imaging in 55-year-old patients compared with $20 931 in 85-year-old patients). Conclusion Screening for large-vessel occlusion with CT angiography in patients with acute minor stroke is cost-effective and associated with improved health outcomes. Undetected large-vessel occlusion in the absence of vascular imaging results in worse health outcomes and higher costs. © RSNA, 2020 Online supplemental material is available for this article.

Management of Unruptured Intracranial Aneurysms in Older Adults: A Cost-effectiveness Analysis.

Background Unruptured intracranial aneurysms (UIAs) are relatively common and are being increasingly diagnosed, with a significant proportion in older patients (˃ 65 years old). Serial imaging is often performed to assess change in size or morphology of UIAs since growing aneurysms are known to be at high risk for rupture. However, the frequency and duration of surveillance imaging have not been established. Purpose To evaluate the cost-effectiveness of routine treatment (aneurysm coil placement) versus four different strategies for imaging surveillance of UIAs in adults older than 65 years. Materials and Methods A Markov decision-analytic model was constructed from a societal perspective. Age-dependent input parameters were obtained from published literature. Analysis included adults older than 65 years, with incidental detection of UIA and no prior history of subarachnoid hemorrhage. Five different management strategies for UIAs in older adults were evaluated: (a) annual MR angiography, (b) biennial MR angiography, (c) MR angiography every 5 years, (d) coil placement and follow-up, and (e) limited MR angiography follow-up for the first 2 years after detection only. Outcomes were assessed in terms of quality-adjusted life-years (QALYs). Probabilistic, one-way, and two-way sensitivity analyses were performed. Results Imaging follow-up for the first 2 years after detection is the most cost-effective strategy (cost = $24 572, effectiveness = 13.73 QALYs), showing the lowest cost and highest effectiveness. The conclusion remains robust in probabilistic and one-way sensitivity analyses. Time-limited imaging follow-up remains the optimal strategy when the annual growth rate and rupture risk of growing aneurysms are varied. If annual rupture risk of nongrowing aneurysms is greater than 7.1%, coil placement should be performed directly. Conclusion Routine preventive treatment or periodic, indefinite imaging follow-up is not a cost-effective strategy in all adults older than 65 years with unruptured intracranial aneurysms. More aggressive management strategies should be reserved for patients with high risk of rupture, such as those with aneurysms larger than 7 mm and those with aneurysms in the posterior circulation. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Cloft in this issue.

Transcatheter Dialysis Conduit Procedures: Changing National and State-Level Medicare Use Patterns over 15 Years.

PURPOSE: To evaluate the changing use of transcatheter hemodialysis conduit procedures. METHODS: Multiple Centers for Medicare & Medicaid Services datasets were used to assess hemodialysis conduit angiography. Use was normalized per 100,000 beneficiaries and stratified by specialty and site of service. RESULTS: From 2001 to 2015, hemodialysis angiography use increased from 385 to 1,045 per 100,000 beneficiaries (compound annual growth rate [CAGR], +7.4%)]. Thrombectomy use increased from 114 to 168 (CAGR, +2.8%). Angiography and thrombectomy changed, by specialty, +1.5% and -1.3% for radiologists, +18.4% and +14.4% for surgeons, and +24.0% and +17.7% for nephrologists, respectively. By site, angiography and thrombectomy changed +29.1% and +20.7% for office settings and +0.8% and -2.4% for hospital settings, respectively. Radiologists' angiography and thrombectomy market shares decreased from 81.5% to 37.0% and from 84.2% to 47.3%, respectively. Angiography use showed the greatest growth for nephrologists in the office (from 5 to 265) and the greatest decline for radiologists in the hospital (299 to 205). Across states in 2015, there was marked variation in the use of angiography (0 [Wyoming] to 1173 [Georgia]) and thrombectomy (0 [6 states] to 275 [Rhode Island]). Radiologists' angiography and thrombectomy market shares decreased in 48 and 31 states, respectively, in some instances dramatically (eg, angiography in Nevada from 100.0% to 6.7%). CONCLUSIONS: Dialysis conduit angiography use has grown substantially, more so than thrombectomy. This growth has been accompanied by a drastic market shift from radiologists in hospitals to nephrologists and surgeons in offices. Despite wide geographic variability nationally, radiologist market share has declined in most states.

Disparities over Time in Volume, Day of the Week, and Patient Complexity between Paracentesis and Thoracentesis Procedures Performed by Radiologists versus Those Performed by Nonradiologists.

PURPOSE: To compare the disparities between the paracenteses and thoracenteses performed by radiologists with those performed by nonradiologists over time. Variables included the volume of procedures, the days of the week, and the complexity of the patient's condition. MATERIALS AND METHODS: Using carrier claims files for a 5% national sample of Medicare beneficiaries from 2004 to 2016, paracentesis and thoracentesis examinations were retrospectively classified by physician specialty (radiologist vs nonradiologist), day of the week (weekday vs weekend), and the complexity of the patient's condition (using Charlson comorbidity index scores). The Pearson chi-square and independent samples t-test were used for statistical analysis. RESULTS: Between 2004 and 2016, the proportion of all paracentesis and thoracentesis procedures performed by radiologists increased from 70% to 80% and from 47% to 66%, respectively. Although radiologists increasingly performed more of both services on both weekends and weekdays, the share performed by radiologists was lower on weekends. For most of the first 9 years across the study period, radiologists performed paracentesis in patients with more complex conditions than those treated by nonradiologists, but the complexity of patients' conditions was similar during recent years. For thoracentesis, the complexity of patients' conditions was similar for both specialty groups across the study period. CONCLUSIONS: The proportion of paracentesis and thoracentesis procedures performed in Medicare beneficiaries by radiologists continues to increase, with radiologists increasingly performing most of both services on weekends. Nonetheless, radiologists perform disproportionately more on weekdays than on weekends. Presently, radiologists and nonradiologists perform paracentesis and thoracentesis procedures in patients with similarly complex conditions. These interspecialty differences in timing and complexity of the patient's condition differ from those recently described for several diagnostic imaging services, reflecting the unique clinical and referral patterns for invasive versus diagnostic imaging services.

Nationwide Trends in Use of Catheter-Directed Therapy for Treatment of Pulmonary Embolism in Medicare Beneficiaries from 2004 to 2016.

PURPOSE: To evaluate changes in the use of catheter-directed therapy (CDT) for pulmonary embolism (PE) treatment with attention to primary operator specialty in the Medicare population. METHODS: Using a 5% national sample of Medicare claims data from 2004 to 2016, all claims associated with PE were identified. The annual volume of 2 billable CDT services-arterial mechanical thrombectomy and transcatheter arterial infusion for thrombolysis-were determined to evaluate changes in CDT use and primary CDT operator specialty over time. RESULTS: The total number of CDT procedures increased over the course of the study period, representing 0.457 and 5.057 service counts per 100,000 Medicare beneficiaries in 2004 and 2016, respectively. The proportion of PEs treated with CDT increased 10-fold from 2004 to 2016, increasing from 0.1% to 1.0%. Interventional radiologists performed most CDT therapies each year, with the exception of 2010 when vascular surgeons performed more. In 2016, interventional radiologists performed 3.54 CDT services for PE per 100,000 Medicare beneficiaries, which was 70% of total CDT for PE procedures, followed by interventional cardiologists and vascular surgeons performing 0.92 services (18%) and 0.60 services (12%), respectively. CONCLUSIONS: CDT is an increasingly used treatment for PE, with a 10-fold increase from 2004 to 2016. Interventional radiologists are the dominant providers of these services, followed by interventional cardiologists and vascular surgeons.

State-Level Variation in Inferior Vena Cava Filter Utilization Across Medicare and Commercially Insured Populations.

OBJECTIVE. Recent research on inferior vena cava (IVC) filter utilization in the United States has largely focused on national aggregate Medicare datasets, showing recent declines. Whether these national Medicare trends are generalizable across regions and payer populations is unknown. We studied recent state-level variation in IVC filter utilization across both Medicare and private insurance populations. MATERIALS AND METHODS. Using large individual beneficiary claims-level Medicare research identifiable files and a proprietary U.S. research database of the commercially insured population, we identified all billed IVC filter placement procedures performed between 2009 and 2015. We compared population-adjusted utilization rates by state and payer type. RESULTS. Between 2009 and 2015, IVC filter utilization across the United States declined by 36.3% (from 177.9 to 113.3 procedures per 100,000 beneficiaries) in the Medicare population and by 26.6% (from 32.7 to 24.0 procedures per 100,000 beneficiaries) in the privately insured population. For the Medicare population, state-level utilization rates varied 5.2-fold, from 48.4 to 251.3 procedures per 100,000 beneficiaries in Alaska and New Jersey, respectively. For the private insurance population, rates varied 5.5-fold, from 10.8 to 59.5 procedures per 100,000 beneficiaries in Oregon and Michigan, respectively. Nationally, utilization in the Medicare population was 5.0 times higher than that in the private insurance population (range by state, from 2.0 times higher in Hawaii to 11.1 times higher in Utah). Despite the national decline, utilization in Medicare and private insurance populations increased in five and seven states, respectively. State-level IVC filter utilization rates for the Medicare population correlated strongly with those for the privately insured population (r = 0.74; p < 0.001). In both the Medicare and privately insured populations, utilization rates correlated moderately with beneficiary age (r = 0.44 and r = 0.50, respectively; p < 0.001 for both). CONCLUSION. IVC filter utilization rates vary dramatically by state and payer population, and they likely depend in part on the age of the covered population. To better identify demographic and socioeconomic drivers of utilization, future research should prioritize nonaggregate multipayer claims-level approaches.

Diagnostic Imaging Examinations Interpreted by Nurse Practitioners and Physician Assistants: A National and State-Level Medicare Claims Analysis.

OBJECTIVE. Nonphysician providers (NPPs) increasingly perform imaging-guided procedures, but their roles interpreting imaging have received little attention. We characterize diagnostic imaging services rendered by NPPs (i.e., nurse practitioners and physician assistants) in the Medicare population. MATERIALS AND METHODS. Using 1994-2015 Medicare Physician/Supplier Procedure Summary Master Files, we identified all diagnostic imaging services, including those billed by NPPs, and categorized these by modality and body region. Using 2004-2015 Medicare Part B 5% Research Identifiable File Carrier Files, we separately assessed state-level variation in imaging services rendered by NPPs. Total and relative utilization rates were calculated annually. RESULTS. Between 1994 and 2015 nationally, diagnostic imaging services increased from 339,168 to 420,172 per 100,000 Medicare beneficiaries (an increase of 24%). During this same period, diagnostic imaging services rendered by NPPs increased 14,711% (from 36 to 5332 per 100,000 beneficiaries) but still represented only 0.01% and 1.27% of all imaging in 1994 and 2015, respectively. Across all years, radiography and fluoroscopy constituted most of the NPP-billed imaging services and remained constant over time (e.g., 94% of all services billed in 1994 and 2015), representing only 0.01% and 2.1% of all Medicare radiography and fluoroscopy services. However, absolute annual service counts for NPP-billed radiography and fluoroscopy services increased from 10,899 to 1,665,929 services between 1994 and 2015. NPP-billed imaging was most common in South Dakota (7987 services per 100,000 beneficiaries) and Alaska (6842 services per 100,000 beneficiaries) and was least common in Hawaii (231 services per 100,000 beneficiaries) and Pennsylvania (478 services per 100,000 beneficiaries). CONCLUSION. Despite increasing roles of NPPs in health care across the United States, NPPs still rarely interpret diagnostic imaging studies. When they do, it is overwhelmingly radiography and fluoroscopy. Considerable state-to-state variation exists and may relate to local care patterns and scope-of-practice laws.

Generalist versus Subspecialist Characteristics of the U.S. Radiologist Workforce.

Purpose To assess subspecialty practice characteristics of the U.S. radiologist workforce. Materials and Methods This study used the Medicare Physician and Other Supplier Public Use File and did not constitute human subject research. The authors identified 33 090 radiologists who billed for professional services between 2012 and 2014 and used a validated classification system to map services to seven subspecialties and quantify subspecialty-focused effort on the basis of work relative value units (RVUs). Radiologists with more than half of their billed work RVUs in a single subspecialty were designated subspecialists; the remainder were classified as generalists. Matching radiologists with various characteristics extracted from other publicly available data sets, associations were explored through use of analysis of variance and multivariable logistic regression. Results More than half (55.3%) of U.S. radiologists practice predominantly as generalists but dedicate on average 36.0% effort to one subspecialty. Among radiologists practicing as majority subspecialists, neuroradiologists (10.1% of all radiologists) and breast imagers (8.4%) are most common. Subspecialization is more common (P < .001) among radiologists who are female, are earlier in their career, work in larger practices, have academic affiliations, and practice in the Northeast. By subspecialty, female representation varies from 8.6% (interventional radiology) to 63.1% (breast imaging); cardiothoracic imagers were more commonly early career radiologists, and nuclear medicine physicians were later career radiologists. Subspecialization is considerably more common in larger (≥100 members) practices (63.1%). An academic affiliation is the strongest independent predictor of subspecialization (odds ratio, 3.56; 95% confidence interval: 3.30, 3.84). Conclusion Despite an increased focus on radiology subspecialization, most U.S. radiologists are majority general radiologists on the basis of their work RVUs. Subspecialization is by far more prevalent in larger and academic practices. © RSNA, 2017 Online supplemental material is available for this article.

Use of Breast Cancer Screening and Its Association with Later Use of Preventive Services among Medicare Beneficiaries.

Purpose To retrospectively assess whether there is an association between screening mammography and the use of a variety of preventive services in women who are enrolled in Medicare. Materials and Methods U.S. Medicare claims from 2010 to 2014 Research Identifiable Files were reviewed to retrospectively identify a group of women who underwent screening mammography and a control group without screening mammography in 2012. The screened group was divided into positive versus negative results at screening, and the positive subgroup was divided into false-positive and true-positive findings. Multivariate logistic regression models and inverse probability of treatment weighting were used to examine the relationship between screening status and the probabilities of undergoing Papanicolaou test, bone mass measurement, or influenza vaccination in the following 2 years. Results The cohort consisted of 555 705 patients, of whom 185 625 (33.4%) underwent mammography. After adjusting for patient demographics, comorbidities, geographic covariates, and baseline preventive care, women who underwent index screening mammography (with either positive or negative results) were more likely than unscreened women to later undergo Papanicolaou test (odds ratio [OR], 1.49; 95% confidence interval: 1.40, 1.58), bone mass measurement (OR, 1.70; 95% confidence interval: 1.63, 1.78), and influenza vaccine (OR, 1.45; 95% confidence interval: 1.37, 1.53). In women who had not undergone these preventive measures in the 2 years before screening mammography, use of these three services after false-positive findings at screening was no different than after true-negative findings at screening. Conclusion In beneficiaries of U.S. Medicare, use of screening mammography was associated with higher likelihood of adherence to other preventive guidelines, without a negative association between false-positive results and cervical cancer screening.

Evolving Use of Prebiopsy Prostate Magnetic Resonance Imaging in the Medicare Population.

PURPOSE: We assessed the changing use of prebiopsy prostate magnetic resonance imaging in Medicare beneficiaries. MATERIALS AND METHODS: Men who underwent prostate biopsy were identified in 5% Medicare RIFs (Research Identifiable Files) from October 2010 through September 2015. We evaluated the rate of prebiopsy prostate magnetic resonance imaging, defined as any pelvic MRI 6 months or less before biopsy with a prostate indication diagnosis code. Temporal changes were determined as well as variation by geography and among populations. RESULTS: In male Medicare beneficiaries the prebiopsy magnetic resonance imaging use rate increased from 0.1% in 2010 to 0.7% in 2011, to 1.2% in 2012, to 2.9% in 2013, to 4.7% in 2014 and to 10.3% in 2015. In 2015 the prebiopsy prostate magnetic resonance imaging rate varied significantly by patient age, including 5.7% for greater than 80 years vs 8.4% to 9.3% for other age ranges (p = 0.040) as well as by race, including 5.8% in African American vs 10.1% in Caucasian men (p = 0.009) and geographic region, including 6.3% in the Midwest to 12.5% in the Northeast (p <0.001). The rate was highest in Wyoming at 25.0%, New York at 23.7% and Minnesota at 20.5% but it was less than 1% in 10 states. CONCLUSIONS: Historical Medicare claims provide novel insights into the dramatically increasing adoption of magnetic resonance imaging prior to prostate biopsy. Following earlier minimal use the performance increased sharply beginning in 2013, exceeding 10% in 2015. However, substantial racial and geographic variation exists in adoption. Continued educational, research and policy efforts are warranted to optimize the role of prebiopsy magnetic resonance imaging and minimize sociodemographic and geographic disparities.

The effect of Medicare's Annual Wellness Visit on preventive care for the elderly.

The study aim was to assess the effect of receiving an Annual Wellness Visit (AWV) between 2011 and 2013 on the annual rate of eight preventive services recommended for the Medicare population following the AWV. We used retrospective Medicare claims from 2009 to 2014 for a 5% national sample of fee-for-service beneficiaries in the United States. Propensity score-adjusted logistic regressions were performed to estimate the log odds of the probability of receiving the preventive services between beneficiaries who received AWVs during 2011-13 and those who did not during the same period. The average marginal effect was also reported. Among 845,318 patients who met the inclusion and exclusion criteria, 23% had an AWV in 2011-2013. In a propensity-matched sample of 381,934 patients, AWV participants are more likely to undergo subsequent preventive services within a year (adjusted odds ratio ranges from 1.46 (95% CI, 1.44, 1.49) to 2.43 (95% CI, 2.38, 2.49). The findings are consistent using secondary outcomes or with subgroups defined by baseline primary care provider visits or baseline preventive services. These analyses showed that AWV is associated with a significant increase in all the preventive services examined. As Healthy People 2020 has established a target goal to increase the proportion of older adults who receive a core set of clinical preventive services by 10%, AWV represents a promising opportunity to facilitate the delivery of preventive care for the elderly and to advance our knowledge about effective strategies for healthy aging.

Day of Week, Site of Service, and Patient Complexity Disparities in Musculoskeletal MRI Interpretations by Radiologists Versus Nonradiologists.

OBJECTIVE: Although most musculoskeletal MRI examinations are interpreted by radiologists, some nonradiologists provide interpretations as well. We aimed to study day of week (weekday vs weekend), site of service, and patient complexity differences between radiologists and nonradiologists interpreting lower extremity MRI examinations on Medicare beneficiaries. MATERIALS AND METHODS: Using fee-for-service carrier claims for a 5% sample of Medicare beneficiaries nationally from 2012 through 2014, we identified all lower extremity joint MRI examinations. Services were classified by physician specialty, day of week, and site of service. Charlson comorbidity index (CCI) values were calculated for all patients. Chi-square statistical testing was performed. RESULTS: Of all 125,800 billed lower extremity joint MRI examinations, 118,295 (94.0%) were performed on weekdays and 7505 (6.0%) on weekends. Of the weekday examinations, radiologists interpreted 85,991 (83.3%) and nonradiologists 17,260 (16.7%). Of the weekend examinations, radiologists interpreted 6212 (92.8%) and nonradiologists 485 (7.2%). Of examinations performed in inpatient hospital and emergency department settings, radiologists interpreted 6499 (99.2%) and nonradiologists 51 (0.8%). Of the examinations on the most clinically complex patients (CCI ≥ 3), radiologists interpreted 4228 (90.2%) and nonradiologists 461 (9.8%). All interspecialty differences were statistically significant (p < 0.001). CONCLUSION: In the Medicare population, radiologists interpret most lower extremity joint MRI examinations. Compared with nonradiologists, radiologists disproportionately provide services on weekends, in the highest acuity settings, and on the most clinically complex patients. To promote patient access and minimize disparities, future pay-for-performance metrics should consider temporal, acuity, and complexity parameters.

Changing Utilization of Noninvasive Diagnostic Imaging Over 2 Decades: An Examination Family-Focused Analysis of Medicare Claims Using the Neiman Imaging Types of Service Categorization System.

OBJECTIVE: The objective of our study was to use a new modality and body region categorization system to assess changing utilization of noninvasive diagnostic imaging in the Medicare fee-for-service population over a recent 20-year period (1994-2013). MATERIALS AND METHODS: All Medicare Part B Physician Fee Schedule services billed between 1994 and 2013 were identified using Physician/Supplier Procedure Summary master files. Billed codes for diagnostic imaging were classified using the Neiman Imaging Types of Service (NITOS) coding system by both modality and body region. Utilization rates per 1000 beneficiaries were calculated for families of services. RESULTS: Among all diagnostic imaging modalities, growth was greatest for MRI (+312%) and CT (+151%) and was lower for ultrasound, nuclear medicine, and radiography and fluoroscopy (range, +1% to +31%). Among body regions, service growth was greatest for brain (+126%) and spine (+74%) imaging; showed milder growth (range, +18% to +67%) for imaging of the head and neck, breast, abdomen and pelvis, and extremity; and showed slight declines (range, -2% to -7%) for cardiac and chest imaging overall. The following specific imaging service families showed massive (> +100%) growth: cardiac CT, cardiac MRI, and breast MRI. CONCLUSION: NITOS categorization permits identification of temporal shifts in noninvasive diagnostic imaging by specific modality- and region-focused families, providing a granular understanding and reproducible analysis of global changes in imaging overall. Service family-level perspectives may help inform ongoing policy efforts to optimize imaging utilization and appropriateness.

Modeling and designing health care payment innovations for medical imaging.

Payment innovations that better align incentives in health care are a promising approach to reduce health care costs and improve quality of care. Designing effective payment systems, however, is challenging due to the complexity of the health care system with its many stakeholders and their often conflicting objectives. There is a lack of mathematical models that can comprehensively capture and efficiently analyze the complex, multi-level interactions and thereby predict the effect of new payment systems on stakeholder decisions and system-wide outcomes. To address the need for multi-level health care models, we apply multiscale decision theory (MSDT) and build upon its recent advances. In this paper, we specifically study the Medicare Shared Savings Program (MSSP) for Accountable Care Organizations (ACOs) and determine how this incentive program affects computed tomography (CT) use, and how it could be redesigned to minimize unnecessary CT scans. The model captures the multi-level interactions, decisions and outcomes for the key stakeholders, i.e., the payer, ACO, hospital, primary care physicians, radiologists and patients. Their interdependent decisions are analyzed game theoretically, and equilibrium solutions - which represent stakeholders' normative decision responses - are derived. Our results provide decision-making insights for the payer on how to improve MSSP, for ACOs on how to distribute MSSP incentives among their members, and for hospitals on whether to invest in new CT imaging systems.

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

OBJECTIVE: To assess for changes in emergency department (ED) utilization of neuroimaging in Medicare fee-for-service beneficiaries from 1994 to 2015. METHODS: Using Medicare Physician Supplier Procedure Summary Master Files, annual ED volumes of head computed tomography (CT), magnetic resonance (MR), and carotid duplex ultrasound (CDUS) were assessed from 1994 through 2015. Annual volumes of head CT angiography (CTA), neck CTA, head MR angiography (MRA), and neck MRA studies were assessed from 2001 (first year of unique reporting codes) through 2015. Longitudinal population-based utilization rates were calculated using annual Medicare Part B enrollment, and utilization rates were normalized annually per 1000 ED visits. RESULTS: From 1994 through 2015, ED neuroimaging utilization rates per 1000 ED visits increased 660% overall (compound annual growth rate [CAGR] 9%); 529% for head CT (CAGR 9%); 1451% for head MRI (CAGR 14%); and by 104% for CDUS (CAGR 3%). From 2001 to 2015, rates increased 14,600% (CAGR 43%) and 17,781% (CAGR 45%) for head and neck CTA, respectively, and 525% (CAGR 14%) and 667% (CAGR 16%) for head and neck MRA, respectively. Trends were similar when volumes were normalized for annual Medicare fee-for-service enrollment. Non-contrast head CT was the most common imaging modality throughout the study period (86% of annual neuroimaging volume in 1994; 89% in 2015). CONCLUSIONS: In Medicare beneficiaries, neuroimaging utilization in the ED grew unabated from 1994 through 2015, with growth of head and neck CTA far outpacing other modalities. Non-contrast head CT remains by far the dominant ED neuroimaging examination.