Medicare Utilization of Vascular Ultrasound From 1998 to 2013: Continued Growth in Both Radiologist and Nonradiologist Imaging

Non-Vascular Considerations When Interpreting Extremity Arterial and Venous Examinations

Peripheral arterial and venous examinations are performed regularly in vascular labs and interpreted by physicians of different specialities. Many vascular examinations have nonvascular pathology that is either inadvertently imaged by the sonographer or imaged with intent as it relates to patient's symptoms. It is prudent for every reader of vascular studies to be acquainted with the sonographic appearance of these non-vascular lesions to enable appropriate and optimal interpretation that has a direct bearing on patient's clinical care. Our review includes a discussion of the nonvascular pathologies like lymph nodes, soft tissue edema, soft tissue fluid collections, musculotendinous injuries, soft tissue masses, and joint and bursal pathologies that may be encountered during interpretation of vascular exams. The pictorial essay includes a discussion of their sonographic appearances and pitfalls in interpretation. Multiple illustrative examples and sonographic images of the non-vascular pathologies found during interpretation of vascular studies have been utilized to highlight their appearances.

Day of Week, Site of Service, and Patient Complexity Differences in Venous Ultrasound Interpreted by Radiologists Versus Nonradiologists

OBJECTIVE

Nationally, nonradiologists interpret an increasing proportion of lower extremity venous duplex ultrasound (LEVDU) examinations. We aimed to study day of week, site of service, and patient complexity differences in LEVDU services interpreted by radiologists versus nonradiologists.

MATERIALS AND METHODS

Using carrier claims files for a 5% national sample of Medicare beneficiaries from 2012 to 2015, we retrospectively classified all LEVDU examinations by physician specialty (radiologist versus nonradiologist), day of week (weekday versus weekend), site of service, and patient Charlson Comorbidity Index (CCI) scores. Pearson's χ² was used to test statistical significance.

RESULTS

Of 760,433 LEVDU examinations for which provider specialty could be determined, 439,964 (58%) were interpreted by radiologists and 320,469 (42%) by nonradiologists. On weekends, radiologists interpreted 75% (66,094 of 88,244) and nonradiologists 25% (22,150 of 88,244) (P < .0001). Of LEVDU examinations interpreted by radiologists, 57% were performed in the inpatient or emergency department settings, and 70% of LEVDU examinations interpreted by nonradiologists were performed in the private office or outpatient hospital setting. Radiologists interpreted a slightly larger proportion (17%) of their examinations on patients with more comorbidities (CCI of ≥3) than nonradiologists (15%) (P < .0001).

CONCLUSION

Compared with nonradiologists, radiologists interpret a disproportionately larger share of weekend (versus weekday) LEVDU examinations and a considerably larger proportion in higher acuity settings. Additionally, the patients on whom they render services have more comorbidities. To optimize around-the-clock patient access to necessary imaging, emerging quality payment programs should consider the timing and sites of service, as well as patient complexity.

Changes in Emergency Department Imaging: Perspectives From National Patient Surveys Over Two Decades

PURPOSE

To use patient-generated data to assess the changing role of emergency department (ED) imaging for a spectrum of clinical indications.

METHODS

The Household Component Emergency Room Visits File was obtained from 1996 through 2014 for the Medical Expenditure Panel Survey, a nationally representative survey of US households. Percentage of visits associated with various imaging modalities was computed annually, stratified by respondents' self-reported primary condition during the visit. Modality characteristics were assessed for conditions most frequently imaged in 1996 or 2014.

RESULTS

For most conditions, use of advanced imaging (defined by Medical Expenditure Panel Survey as CT or MRI) in the ED increased significantly (P < .001). The largest growth occurred for urinary calculus (from 0% to 48.5%) and headache (from 17.5% to 33.3%), which were the most commonly imaged conditions by CT or MRI in 2014. For ultrasound, the most commonly imaged condition was pregnancy in 1996 (32.9%) and 2014 (44.5%). No other condition was associated with ultrasound in >20% of visits. For radiography, the most commonly imaged conditions were extremity wounds and fractures in 1996 (range 84.5%-90.2%) and 2014 (range 93.4%-93.9%). Use of radiography decreased for urinary calculus from 67.4% to 24.2% (P < .001).

CONCLUSION

For many conditions, ED utilization of advanced imaging increased significantly, though growth was variable across conditions. In certain scenarios, advanced ED imaging is adding to, rather than replacing, other modalities. Ultrasound and radiography utilization was overall unchanged. That national patient survey data mirror traditional claims-based studies suggests an expanded role for patient-generated data in identifying areas of imaging utilization that may benefit from targeted optimization efforts.

Medicare Utilization of CT Angiography from 2001 through 2014: Continued Growth by Radiologists

PURPOSE

To examine changes in utilization of computed tomography (CT) angiography nationally and changing relative specialty roles in examination interpretation.

MATERIALS AND METHODS

Service-specific claims data for region-specific CT angiography examinations were identified using Medicare Physician Supplier Procedure Summary Master Files from 2001 through 2014. Longitudinal national utilization rates were calculated using annual Medicare enrollment data for 2001-2013. Procedure volumes by specialty group and site of service were analyzed.

RESULTS

Total annual claims for CT angiography for Medicare fee for service beneficiaries increased from 64,846 to 1,709,088 (compound annual growth rate [CAGR] 29%) between 2001 and 2014. Per 1,000 beneficiaries, overall CT angiography utilization increased annually from 2.1 in 2001 to 47.6 in 2013. Overall interpretation market share increased 4% (91%-95%) for radiology. Cardiology increased from 1% in 2001 to 6% in 2007 but decreased annually to 2% in 2014. Vascular surgery market share remained < 1% throughout the study period. Growth of CT angiography in the emergency department (ED) outpaced all other sites of service, increasing from 11% to 28% (CAGR 38%). The chest was the dominant body region imaged with CT angiography, increasing from 36,984 to 914,086 (CAGR 28%).

CONCLUSIONS

Utilization of CT angiography in the Medicare population increased markedly for 2001-2014, particularly in the ED, with radiologists remaining dominant providers. The chest is the most common body region imaged with CT angiography.