Faculty Bibliography

OBJECTIVE:The purpose of this study is to identify the specialty characteristics of providers referring musculoskeletal (MSK) extremity imaging examinations to radiologists, so as to better understand the drivers of MSK imaging utilization and potentially improve the appropriateness of such imaging examinations. MATERIALS AND METHODS/METHODS:Data on provider referral for MSK extremity imaging services were extracted from the 2014 Medicare Referring Provider Utilization for Procedures public use file, which aggregates data on diagnostic procedures according to referring provider identities and service codes. MSK extremity imaging services were identified using Neiman Institute Types of Service codes. The referring provider specialty was identified from cross-linked Medicare provider characteristics files. RESULTS:For 4,275,647 MSK extremity imaging examinations ordered, the most common specialties of the referring providers were orthopedic surgery (37.6% of ordered examinations), internal medicine (20.2%), family practice (14.8%), emergency medicine (7.9%), and rheumatology (5.7%). Orthopedic surgery was the referring specialty that most commonly ordered MSK extremity CT (33,465 ordered examinations; for all other specialties, < 2000 examinations), MRI (325,485 examinations; for all other specialities, < 20,000 examinations), and radiography (1,249,748 examinations; for all other specialities, < 850,000 examinations), whereas internal medicine was the referring specialty that most commonly ordered MSK extremity ultrasound examinations (8052 ordered examinations; for all other specialties, < 6000 examinations). Among the select specialties most relevant to MSK imaging, the most frequent referrers after orthopedic surgeons were rheumatologists, for radiography (236,057 ordered examinations) and ultrasound (2034 examinations), and podiatrists, for CT (1201 examinations) and MRI (19,159 examinations). The most commonly ordered individual MSK extremity imaging services were knee radiography, with 190,354 examinations ordered by orthopedic surgeons; hand radiography, with 66,167 examinations ordered by rheumatologists; foot radiography, with 137,042 examinations ordered by podiatrists; shoulder radiography, with 11,299 examinations ordered by sports medicine specialists; and hip radiography, with 9838 examinations ordered by physiatrists. CONCLUSION/CONCLUSIONS:Referral patterns for MSK imaging vary considerably by provider specialty. Referral pattern insights may guide targeted efforts by radiologists to ensure the appropriateness of such examinations.

Purpose: To characterize Medicare services billed by current SSR members. Materials and Methods: With SSR Executive Committee permission, national provider identifiers (NPIs) were manually identified for all SSR members (who had all attested to >50% of one's practice in musculoskeletal [MSK] radiology). NPIs permitted member cross-linking to the 2015 CMS Physician and Other Supplier Public Use File to then identify all services each billed Medicare. Service codes were mapped to seven mapping-validated subspecialties (MSK, abdominal, breast, cardiothoracic, neuroradiology, nuclear medicine, and vascular-interventional radiology [VIR]) using the Neiman Imaging Types of Service classification system. Radiologists' percentages of work RVUs (wRVU) in each subspecialty were computed. Various subgroup analyses were performed. Results: Of 1,014 SSR members, 49.5% performed >=50% of their wRVUs in MSK. In terms of billed wRVUs, 53.4% of these radiologists mapped to a secondary subspecialty of neuroradiology in terms of billed wRVUs, 16.3% to abdominal, 11.8% to cardiothoracic, and 5.2% to VIR. Of all SSR members, 45.6% were generalists (i.e., no subspecialty crossed the majority wRVU threshold), but 37.4% of them performed a plurality of work in MSK. No other subspecialty accounted for greater than 2% of SSR members. A higher percentage of MSK wRVUs was significantly associated (p<0.001) with an academic affiliation (66.8% vs. 44.5%) as well as two different markers of greater SSR engagement: 1) attending the 2014 SSR meeting (63.5% vs. 49.9%) and 2) serving as an SSR committee member (75.7% vs. 51.6%). Of all other 27,618Medicare-participating radiologists nationally meeting inclusion criteria, 3.2% (879) had >=50% of their wRVUs in MSK but are not SSR members. Conclusion: Medicare claims-based practice classification provides unique insight into SSR membership. This information may help better understand current membership needs, plan future meeting content, and guide further society growth

Multiparametric MR imaging provides detailed anatomic assessment of the prostate as well as information that allows the detection and characterization of prostate cancer. To obtain high-quality MR imaging of the prostate, radiologists must understand sequence optimization to overcome commonly encountered technical challenges. This review discusses the techniques that are used in state-of-the-art MR imaging of the prostate, including imaging protocols, hardware considerations, and important aspects of patient preparation, with an emphasis on the recommendations provided in the prostate imaging-reporting and data system version 2 guidelines.

PURPOSE/OBJECTIVE:To assess changing utilization of pre-biopsy prostate MRI in Medicare beneficiaries. MATERIALS AND METHODS/METHODS:Men undergoing prostate biopsy were identified in 5% Medicare Research Identifiable Files from October 2010 through September 2015. Rates of pre-biopsy prostate MRI (any pelvic MRI ≤6 months before biopsy with a prostate indication diagnosis code) were assessed. Temporal changes and variation by geography and among populations were determined. RESULTS:In male Medicare beneficiaries, pre-biopsy MRI utilization rates increased from 0.1% in 2010 to 0.7% in 2011, 1.2% in 2012, 2.9% in 2013, 4.7% in 2014, and 10.3% in 2015. In 2015, pre-biopsy prostate MRI rates varied significantly by patient age (5.7% for >80 years vs. 8.4%-9.3% for other age ranges, p=0.040), race (5.8% in blacks vs. 10.1% in whites, p=0.009), and geographic region (from 6.3% in the Midwest to 12.5% in the Northeast; p<0.001). Rates were highest in Wyoming (25.0%), New York (23.7%), and Minnesota (20.5%), but <1% in ten states. CONCLUSION/CONCLUSIONS:Historic Medicare claims provide novel insights into dramatically increasing adoption of MRI prior to prostate biopsy. Following earlier minimal usage, utilization increased sharply beginning in 2013, exceeding 10% in 2015. However, substantial racial and geographic variation in adoption exists. Continued educational, research, and policy efforts are warranted to optimize the role of pre-biopsy MRI and minimize sociodemographic and geographic disparities.

RATIONALE AND OBJECTIVES/OBJECTIVE:The present study aims to assess associations of Medicare beneficiary screening mammography rates with local mammography facility and radiologist availability. MATERIALS AND METHODS/METHODS:Mammography screening rates for Medicare fee-for-service beneficiaries were obtained for US counties using the County Health Rankings data set. County-level certified mammography facility counts were obtained from the United States Food and Drug Administration. County-level mammogram-interpreting radiologist and breast imaging subspecialist counts were determined using Centers for Medicare & Medicaid Services fee-for-service claims files. Spearman correlations and multivariable linear regressions were performed using counties' facility and radiologist counts, as well as counts normalized to counties' Medicare fee-for-service beneficiary volume and land area. RESULTS:Across 3035 included counties, average screening mammography rates were 60.5% ± 8.2% (range 26%-88%). Correlations between county-level screening rates and total mammography facilities, facilities per 100,000 square mile county area, total mammography-interpreting radiologists, and mammography-interpreting radiologists per 100,000 county-level Medicare beneficiaries were all weak (r = 0.22-0.26). Correlations between county-level screening rates and mammography rates per 100,000 Medicare beneficiaries, total breast imaging subspecialist radiologists, and breast imaging subspecialist radiologists per 100,000 Medicare beneficiaries were all minimal (r = 0.06-0.16). Multivariable analyses overall demonstrated radiologist supply to have a stronger independent effect than facility supply, although effect sizes remained weak for both. CONCLUSION/CONCLUSIONS:Mammography facility and radiologist supply-side factors are only weakly associated with county-level Medicare beneficiary screening mammography rates, and as such, screening mammography may differ from many other health-care services. Although efforts to enhance facility and radiologist supply may be helpful, initiatives to improve screening mammography rates should focus more on demand-side factors, such as patient education and primary care physician education and access.

INTRODUCTION/BACKGROUND:The purpose of this study was to explore associations between CT and MRI utilization and cost savings achieved by Medicare Shared Savings Program (MSSP)-participating accountable care organizations (ACOs). METHODS:Summary data were obtained for all MSSP-participating ACOs (n = 214 in 2013; n = 333 in 2014). Multivariable regressions were performed to assess associations of CT and MRI utilization with ACOs' total savings and reaching minimum savings rates to share in Medicare savings. RESULTS:In 2014, 54.4% of ACOs achieved savings, meeting minimum rates to share in savings in 27.6%. Independent positive predictors of total savings included beneficiary risk scores (β = +20,265,720, P = .003) and MRI events (β = +19,964, P = .018) but not CT events (β = +2,084, P = .635). Independent positive predictors of meeting minimum savings rates included beneficiary risk scores (odds ratio = 2108, P = .001) and MRI events (odds ratio = 1.008, P = .002), but not CT events (odds ratio = 1.002, P = .289). Measures not independently associated with savings were total beneficiaries; beneficiaries' gender, age, race or ethnicity; and Medicare enrollment type (P > .05). For ACOs with 2013 and 2014 data, neither increases nor decreases in CT and MRI events between years were associated with 2014 total savings or meeting savings thresholds (P ≥ .466). CONCLUSION/CONCLUSIONS:Higher MRI utilization rates were independently associated with small but significant MSSP ACO savings. The value of MRI might relate to the favorable impact of appropriate advanced imaging utilization on downstream outcomes and other resource utilization. Because MSSP ACOs represent a highly select group of sophisticated organizations subject to rigorous quality and care coordination standards, further research will be necessary to determine if these associations are generalizable to other health care settings.

PURPOSE/OBJECTIVE:To explore associations between county-level measures of radiologist supply and subspecialization and county structural and health-related characteristics. METHODS:Medicare Physician and Other Supplier Public Use Files were used to subspecialty characterize 32,844 radiologists participating in Medicare between 2012 and 2014. Measures of radiologist supply and subspecialization were computed for 3,143 US counties. Additional county characteristics were identified using the 2014 County Health Rankings database. Mann-Whitney tests and Spearman correlations were performed. RESULTS:Counties with at least one (versus no) Medicare-participating radiologist had significantly (P < .001) larger populations (197,050 ± 457,056 versus 20,253 ± 23,689), lower rural percentages (39.5% ± 26.5% versus 74.6% ± 25.6%), higher household incomes ($47,608 ± $12,493 versus $42,510 ± $9,893), higher mammography screening rates (62.4% ± 7.0% versus 56.6% ± 15.3%), and lower premature deaths (7,581 ± 2,085 versus 7,784 ± 3,409 years of life lost). Counties' radiologists per 100,000 population and percent of subspecialized radiologists showed moderate positive correlations with counties' population (r = +0.505-+0.599) and moderate negative correlations with counties' rural percentage (r = -0.434 to -0.523). Radiologist supply and degree of subspecialization both showed concurrent positive or negative weak associations with counties' percent age 65+ (r = -0.256 to -0.271), percent Hispanic (r = +0.209-+0.234), and income (r = +0.230-+0.316). Radiologists per 100,000 population showed weak positive correlation with mammography screening (r = +0.214); percent of radiologists subspecialized showed weak negative correlation with premature death (r = -0.226). CONCLUSION/CONCLUSIONS:Geographic disparities in radiologist supply at the community level are compounded by superimposed variation in the degree of subspecialization of those radiologists. The potential impact of such access disparities on county-level health warrants further investigation.

RATIONALE AND OBJECTIVES/OBJECTIVE:To assess associations between screening mammography utilization and Medicare beneficiaries' relationships with, and impressions of, their primary care physicians. MATERIALS AND METHODS/METHODS:Using the Medicare Current Beneficiary Survey Access to Care Public Use File, we retrospectively studied responses from a national random cross section of Medicare beneficiaries surveyed in 2013 regarding perceptions of their primary care physicians and their screening mammography utilization. Statistical analysis accounted for subject weighting factors to estimate national screening utilization. RESULTS:Among 7492 female Medicare beneficiaries, 62.0% (95% confidence interval 59.8%-64.2%) underwent screening mammography. Utilization was higher for beneficiaries having (vs. not) a regular medical practice or clinic (63.2% vs. 34.6%) and a usual physician (63.8% vs. 50.3%). Utilization was higher for beneficiaries very satisfied (vs. very dissatisfied) with the overall quality of care they received (66.0% vs. 35.8%), their ease of getting to a doctor (67.7% vs. 43.2%), and their physician's concerns for their health (65.7% vs. 53.4%), as well as for beneficiaries strongly agreeing (vs. strongly disagreeing) that their physician is competent (66.0% vs. 54.1%), understands what is wrong (66.3% vs. 47.1%), answers all questions (67.0% vs. 46.7%), and fosters confidence (66.0% vs. 50.6%). Independent predictors of screening mammography utilization (P < .05) were satisfaction with quality of care, having a regular practice or clinic, and satisfaction with ease of getting to their physician. CONCLUSIONS:Screening mammography utilization is higher among Medicare beneficiaries with established primary physician relationships, particularly when those relationships are favorable. To optimize screening mammography utilization, breast imagers are encouraged to support initiatives to enhance high-quality primary care relationships.