etcaiDstddrtdnsopCpdtf

NC1

RA

The Journal of Emergency Medicine, Vol. 38, No. 5, pp. 645–651, 2010Copyright © 2010 Elsevier Inc.

Printed in the USA. All rights reserved0736-4679/$–see front matter

doi:10.1016/j.jemermed.2008.10.016

Ultrasound inEmergency Medicine

ECONOMIC IMPACT OF ADDITIONAL RADIOGRAPHIC STUDIES AFTERREGISTERED DIAGNOSTIC MEDICAL SONOGRAPHER (RDMS)-CERTIFIED

EMERGENCY PHYSICIAN-PERFORMED IDENTIFICATION OF CHOLECYSTITISBY ULTRASOUND

Nicholas Young, MD, RDMS,* Stephen Kinsella, PHD,† Christopher C. Raio, MD, RDMS,* Matthew Nelson, DO, RDMS,*Gerardo Chiricolo, MD, RDMS,* Ashley Johnson, MD, RDMS,* George Malcolm, MD, RDMS,*

Byron C. Drumheller, BA,* Mary Frances Ward, RN, MS,* and Andrew Sama, MD**Department of Emergency Medicine, North Shore University Hospital, Manhasset, New York and †Department of Economics,

University of Limerick, Limerick, IrelandReprint Address: Nicholas Young, MD, Department of Emergency Medicine, North Shore University Hospital, 300 Community Drive,

Manhasset, NY 11030

(ehpciUa$5rEdfaeu

ec

Ava

Abstract—Background: The standard evaluation of pa-ients with right upper quadrant (RUQ) abdominal painonsists of a history and physical examination, laboratorynalysis, and radiological investigation. Given the increas-ng availability of bedside ultrasound in the Emergencyepartment (ED), a growing proportion of Emergency Phy-

icians are now performing their own ultrasound examina-ions in patients with RUQ abdominal pain to circumventiagnostic delays and improve patient care. Objective: Toetermine the economic “opportunity” costs of additionaladiographic testing after identification of acute cholecys-itis by focused ED ultrasound performed by registerediagnostic medical sonographer (RDMS)-certified person-el. Methods: A retrospective analysis of a consecutiveample of patients with “positive” focused ED ultrasoundsf the RUQ that were significant for cholecystitis, whoresented from June 1, 2005 through February 30, 2006.ost analysis was performed using standard Medicare com-ensation indices for radiological examinations of the ab-omen/hepatobiliary system. Results: There were 37 pa-ients enrolled; 32 patients exhibited RUQ pain with aocused ED ultrasound significant for cholecystitis. Eight

The data in this manuscript were presented in abstract form byicholas Young, MD, at the National Meeting of the Americanollege of Emergency Physicians, New Orleans, LA, October5-18, 2006.

ECEIVED: 23 November 2007; FINAL SUBMISSION RECEIVE

CCEPTED: 9 October 2008

645

25%) patients received no further radiographic tests andxhibited positive pathology. Twenty-four (75%) patientsad additional diagnostic examinations; 22 (92%) showedositive pathology. Based upon Medicare compensation indi-es, an opportunity cost of $6885.34 was incurred at ournstitution over 9 months due to additional examinations.sing nationally comparable indices, this was extrapolated ton opportunity cost of $63 million (95% confidence interval48.3–$78.9 million) per year across the nation, assuming that0% of patients with cholecystitis present to the ED andeceive an ultrasound examination by an RDMS-certifiedmergency Physician. Conclusions: In this small sample, ad-itional radiological testing after ED ultrasounds significantor acute cholecystitis led to sizable economic costs on a localnd national level. Formal cost-benefit analyses are needed tovaluate the full economic and patient care implications of EDltrasound use in this setting. © 2010 Elsevier Inc.

Keywords—ultrasound; Emergency Department; chole-ystitis; cost effectiveness; economic analysis

INTRODUCTION

ccording to the Centers for Disease Control and Pre-ention’s National Center for Health Care Statistics,pproximately 20 cholecystectomies are performed an-

ugust 2008;

D: 6 A

nupagv

qpirciAftGtaidsasa

EapaTtsccEa

S

TcUpeeRdt

S

TccRew

ff“dggckppp

M

Udpttrpvtoidsw

D

OwRridMTvdt

646 N. Young et al.

ually per 10,000 people in the United States (1). It isnknown what percentage of these surgical patientsresent to Emergency Departments (EDs) for evaluationnd admission. However, national ED census data sug-est that abdominal pain accounts for roughly 10% of allisits (1).

The standard evaluation of patients with right upperuadrant (RUQ) abdominal pain consists of a history andhysical examination, laboratory analysis, and radiolog-cal investigation. Although there remains some debateegarding the initial radiological study of choice in theseases, with scintigraphy often being shown to be superiorn sensitivity and specificity to RUQ ultrasound, the 2001merican College of Radiology Appropriateness Criteria

or evaluation of acute RUQ pain states that ultrasound ishe most appropriate initial study in this setting (2–4).iven the increasing availability of bedside ultrasound in

he ED, a growing proportion of Emergency Physiciansre now performing their own ultrasound examinationsn patients with RUQ abdominal pain to circumventiagnostic delays and improve patient care. Recent re-earch has shown that Emergency Medicine residentsnd practitioners with moderate levels of training canuccessfully identify cholelithiasis using ultrasound withsensitivity of 92–96% (5–7).Despite the increasing evidence supporting the use of

D ultrasound to accurately detect acute cholecystitis,dditional radiological testing, in the form of radiology-erformed ultrasounds, DISIDA (diisopropyl iminodi-cetic acid) scans, or both, is still commonplace (2).here has been little research done to evaluate the po-

ential impact of these additional tests on the health careystem as a whole. We sought to determine the economicosts associated with additional radiographic testing inases of acute cholecystitis identified by focused RUQD ultrasound, and extrapolate this measure on a localnd national scale.

METHODS

tudy Design

his study was a retrospective analysis of prospectivelyollected quality assurance data from the ED at North Shoreniversity Hospital, an academic tertiary care referral hos-ital. All ED ultrasounds performed by RDMS-certified/ligible Emergency Medicine physicians (REMPs) werevaluated. The study was approved by the Institutionaleview Board. Written informed consent was waivedue to the retrospective nature of the investigation and

he use of previously collected quality assurance data. M

tudy Setting and Population

he setting was an ED of an academic, tertiary care referralenter with a 65,000 annual patient volume. RDMS-ertified/eligible was defined as those physicians withDMS certification or those who had completed or werenrolled in an emergency medicine ultrasound fellowshipith experience of � 800 ultrasound examinations.A consecutive sample of all patients with “positive”

ocused ED ultrasounds of the RUQ performed by REMPsrom June 1, 2005 to February 30, 2006 was evaluated.Positive” was defined as the presence of anterior gallblad-er wall thickening or edema, peri-cholecystic fluid, orallbladder hydrops, all with or without the presence ofallstones. Cases of a stone-in-neck phenomenon were alsoonsidered positive. Patients were excluded if there was anown diagnosis of cholecystitis before the ED study, if theatient left the ED before completion of treatment, or if theatient was not a surgical or imaging candidate due toalliative care status.

easurements

ltrasound findings were prospectively recorded on stan-ardized quality assurance data forms by the REMPerforming the scan. Data were abstracted retrospec-ively by a separate REMP investigator who was blindedo final patient outcomes. Radiology-performed studyeports and pathology data were obtained from the hos-ital’s medical records and abstracted by an REMP in-estigator blinded to the patient’s ED encounter. “Posi-ive” surgical pathology was defined as evidence of acuter chronic cholecystitis. Chart review by two separatenvestigators was performed in cases where pathologyata were not available or the clinical course was incon-istent with the admitting diagnosis. Any discrepanciesere resolved by committee.

ata Analysis

ur primary outcome was the economic costs associatedith additional radiographic studies after ED ultrasound.egardless of whether any reimbursement was actually

eceived by our hospital, a second test being performedmposed a “cost” on the health care system, which weefined using the cost assigned to these studies by theedicare Resource-based Relative Value Scale (8,9).

he basic unit of measurement in this scale is the relativealue unit (RVU). The RVUs for a given test or proce-ure can be broken down into professional (26) andechnical (TC) components (Table 1), as defined by the

edicare RVU scale. To determine the costs of a test, the

RmpGacbitw

Pm

sp“ispr(

ltntcWUHl

pSptc1mEntw(

Aslprfotdv

a

T

2TCT2C

*hurmMC nit.

T

G

A

Opportunity Cost of Additional Radiographic Studies Following Bedside Diagnosis of Cholecystitis 647

VUs for each component were summed, and the total wasultiplied by an annually adjusted conversion factor, which

roduces a dollar cost amount. This is adjusted by theeographical Practice Cost Index, a modifier value that

ccounts for regional variations in resource and physicianosts throughout the country. The RVU is used nationallyy Medicare to determine health care reimbursements ands therefore ideally suited for our local and national hypo-hetical extrapolation. For our analysis, the costs of each testere obtained by applying the following formula:Medicare Fees

� ��Work RVU * Work RVU GPCI Adjustment�� �Facility PE RVU * PE RVU GPCI Adjustment�� �MP RVU * MP RVU GPCI Adjustment��* CF

(RVU � relative value unit; GPCI � Geographicalractice Cost index; PE � practice expense; MP �alpractice; CF � conversion factor).The total costs for our sample were determined by

imple addition of the costs of all radiological testserformed, including ED ultrasound. We defined theopportunity costs” (borne by the health care systemtself) of ordering additional studies as the fees, mea-ured via geographically compensated RVUs, for therofessional and technical components of the additionaladiology-performed ultrasound examinations or HIDAhepatobiliary iminodiacetic acid) scans.

To extrapolate our results to a regional and nationalevel, we calculated a per capita total cost (sum of allotal costs/number of patients) and a per capita opportu-ity cost (sum of all opportunity costs/number of pa-ients), and then multiplied by the estimated number ofases of acute cholecystitis within the geographic region.

e found the population of Nassau County and thenited States (US) in the US Census Bureau’s Americanousehold Survey for 2003 and used current epidemio-

able 1. Ultrasound and Hepatobiliary Imaging Medicare Re

Modifier CPT Code Description

6 76705 Echo examination of aC 76705 Echo examination of aombined (26 � TC) 76705 Echo examination of aC 78223 Hepatobiliary imaging6 78223 Hepatobiliary imagingombined (26 � TC) 78223 Hepatobiliary imaging

Source: US Department of Health and Human Services, Cenths.gov/apps/pfslookup/. This table shows the technical (TC)ltrasound and hepatobiliary imaging in both relative value unitseimbursement component (professional and technical) is furtalpractice portions (MP), which are added to give the total reedicare reimbursement values (column 8).PT � Current Procedural Terminology; RVU � relative value u

ogical estimates of approximately 20 cholecystectomies S

erformed annually per 10,000 people in the Unitedtates (1,10). Because there is no way to tell whatercentage of cases of acute cholecystitis come throughhe ED of a typical Nassau County or US hospital, wealculated our extrapolation assuming, respectively, 1%,0%, 25%, 50%, 75%, and 100% of the cholecystecto-ies performed in Nassau County and the U.S. are seen inmergency Departments. For simplicity, we calculated an-ual costs, assuming that the incidence of cholecystitis inhe time period studied (June 1, 2005–February 30, 2006)as comparable with that for the remainder of the year

March 1, 2006–June 1, 2006).

RESULTS

total of 37 patients were studied; 5 patients wereubsequently excluded (3 with a prior diagnosis of cho-ecystitis, 1 left against medical advice, 1 assigned toalliative care). Table 2 shows the characteristics of theemaining 32 patients studied. All patients had a “positive”ocused RUQ ED ultrasound. Figure 1 shows the clinicalutcomes of the study population at our hospital. Overall,he positive predictive value (PPV) of ED ultrasound toetect acute cholecystitis was 94% (95% confidence inter-al [CI] 87.1–100.0).

Of the 32 consecutive cases of positive ED ultrasounds,further radiological study followed in 24 (75%). The per

sements*

WorkRVU

FAC PERVU MP RVU

TotalRVU

MedicareFee

n 0.00 1.42 0.08 1.50 $74.20n 0.59 0.19 0.03 0.81 $34.77n 0.59 1.61 0.11 2.31 $109.06

0 3.67 0.19 3.86 $190.880.84 0.28 0.04 1.16 $49.780.84 3.95 0.23 5.02 $240.66

Medicare and Medicaid Studies, available at http://www.cms.rofessional (26) components of limited right upper quadrantns 4–7) and Medicare reimbursement values (column 8). Eachdivided into work, facility (FAC), practice expense (PE), and

value units (column 7) and subsequently determined monetary

able 2. Patient Characteristics

ender (n � 32)Female 17 (53%)Male 15 (47%)

geMean (SD) 58 (17)Median (range) 56 (30–90)

imbur

bdomebdomebdome

ers forand p(colum

her sublative

D � standard deviation.

cHTwtt

t(pspm

str$

stf

Ta

Frrsa lse-pod

Fotu

648 N. Young et al.

apita total cost, with the inclusion of Radiology-performedIDA scans, was $324.22 (95% CI $272.52–$375.93).he per capita opportunity cost, including HIDA scans,as $215.17 (95% CI $163.48–$266.87). A total oppor-

unity cost of $6885.34 was incurred at our hospital overhe 9-month study period.

Using the above rationale, this cost was extrapolatedo the regional and national level for a 1-year periodFigures 2 and 3, respectively). Assuming that 50% ofatients undergoing cholecystectomies each year have aimilar ED and radiology evaluation, an estimated op-ortunity cost of $63 million/year (95% CI $48.3–$78.9illion) would be incurred by the national health care

igure 1. Clinical outcomes of patients with positive ED ultread as a diffusely thickened gallbladder wall in the settingevealed documentation by the performing Emergency Phyetting of CHF consistent with the radiology interpretation. Ds per the study design, this case was included in the faiisopropyl iminodiacetic acid.

igure 2. Actual vs. opportunity costs for Nassau County. Thf positive scans of the right upper quadrant indicative of ch

his graph, the whole column represents the cost of all studiesltrasound. The lighter portion of the column represents the oppo

ystem. If only 10% of patients have a similar experienceo those at our hospital, the opportunity cost stillemains upwards of $12 million/year (95 % CI $9.7–15.8 million).

Given that there is debate regarding the use of HIDAcans in the diagnosis of acute cholecystitis, we also ex-rapolated our data to the national level, excluding costsrom any additional HIDA scans performed (Figure 4).

DISCUSSION

his study evaluated the clinical course of patients withcute cholecystitis identified on ultrasound as performed

ds. *In this case, the Radiology-performed ultrasound wasngestive heart failure (CHF). Review of this patient’s chartstating the diagnosis of an edematous gallbladder in thean error in the documentation on the quality assurance logsitive category. ED � Emergency Department; DISIDA �

polated relationship between actual and opportunity coststitis for Nassau County for a hypothetical 1-year period. On

asounof co

sicianue to

e extraolecys

performed, including the Emergency Physician-performedrtunity cost.

acqosaps

ptPtvbr

eatsueg“mm

aosoc

Fha in the

Fgppae

Opportunity Cost of Additional Radiographic Studies Following Bedside Diagnosis of Cholecystitis 649

nd interpreted by REMPs, and determined the economicosts of additional radiographic tests performed subse-uent to ED-based ultrasound examinations,. The resultsf this small sample suggest that the “positive” ultra-ound examinations performed by these physicians wereccurate and that the subsequent radiological tests im-osed a significant economic burden on the health careystem.

Because we did not examine all RUQ ED ultrasoundserformed to evaluate for cholecystitis, we cannot assesshe true accuracy or cost-effectiveness of Emergencyhysician-performed ultrasound in this setting. We chose

o assess ultrasounds performed by only REMPs to pro-ide the most accurate diagnostic findings upon which toase our economic evaluation. Nonetheless, our findingsepresent a small sample of only “positive” ultrasound

igure 3. Actual vs. opportunity cost for the United Stateypothetical 1-year period. On the X axis, the 0.50 representcholecystectomy each year have an equivalent experience

igure 4. Actual vs. opportunity cost, without HIDA (hepatoraph represents the nationally extrapolated data, withouteriod. As there is indeterminate evidence to support the userform the analysis both with and without the cost incu

ssumption that 50% of all patients who undergo a cholecystectovaluation. ED � Emergency Department.

xaminations performed by Emergency Physicians withbove-average training and experience, which may limitheir generalizability. Our goal was not to prove thatingular focused ED ultrasound examinations should besed to diagnose cholecystitis, but rather to examine theconomic implications of additional radiological testing,iven the context of current recommendations (3,11).Additional” radiological studies refer to studies thatay, in the future, be avoidable with reliable emergencyedicine ultrasound examinations.We defined “cost” in this setting as the monetary loss

ssociated with potentially redundant testing. It is basedn the assumption that health care dollars and hourspent in the provision of one service are unavailable forther services, and this imposes a burden on the healthare system overall. The opportunity cost of an economic

graph represents the nationally extrapolated data for aheoretical assumption that 50% of all patients who undergoir initial evaluation. ED � Emergency Department.

iminodiacetic acid) estimates, for the United States. Thising the cost of the HIDA scans, for a hypothetical 1-yearIDA scan as an additional test, we felt it was necessary to

y HIDA. On the X axis, the 0.5 represents the theoretical

s. Thiss the t

biliaryinclude of H

rred b

my each year have an equivalent experience in their initial

egevolpstIprsdaeur

cswtwsdha

tcttfftmncfmp

L

TaEsPets

tattsibttgd

os9ocss

oeTweFmhopriaadtca

Bptrsdoaeso

650 N. Young et al.

vent like ordering an unnecessary test is what has beeniven up to get that test performed (12). The perennialxample is this: if a city decides to build a hospital onacant land that it owns, the opportunity cost is the valuef some other thing that might have been done with theand and construction funds instead. In building the hos-ital, the city has forgone the opportunity to build aporting center or a parking lot on that land, or the abilityo sell the land to reduce the city’s debt, and so on (13).n our study, the “opportunity cost” represents only aortion of the true opportunity cost of the additionaladiographic tests, as the resource-based RVU scale mea-ures only the physician-associated economic costs andoes not take into account the costs to the hospital andncillary staff. On the other hand, our analysis did notxamine the cost of training Emergency Physicians inltrasound competence, which would consume time andesources and tend to minimize potential cost savings.

Further radiological studies followed 75% of the 32ases where a positive ED ultrasound was obtained. Con-equently, we asked the hypothetical question—how muchould have been saved if these tests were not performed? In

he context of our institution, an opportunity cost of $6885as incurred over 9 months. This makes a bold financial

tatement. It also suggests that there are significant excessemands across many measures of “cost” not quantifiedere, such as physician time, hospital technical resources,nd patient length of stay.

The extrapolation of our data to Nassau County andhe entire nation has the merit of producing a comparableost calculation for a larger region given the ubiquity ofhe Medicare reimbursement system. Although this ex-rapolation is limited by our small sample size and theact that all Emergency Physicians are not performingocused ED ultrasounds, our point is to demonstrate thathere is a potential loss occurring, and to hint at itsagnitude. Understanding that there are many elements

ot addressed by our simple definition of opportunityost, we simply seek to emphasize a possible opportunityor health care savings and a potential economic argu-ent for the acceptance and utilization of ultrasounds

erformed by REMPs.

imitations

his study is limited by its small, retrospective samplend inability to assess the full economic significance ofD ultrasound use in the setting of cholecystitis. Thetudy design was retrospective to evaluate cases in vivo.rospective evaluation would introduce the Hawthorneffect; the alteration in subject (physician) practice whenhe subject knows they are under observation. The ab-

ence of a Hawthorne effect was vital to our investiga- e

ion, as we sought to evaluate clinical practice rather thansingle diagnostic modality in isolation. Additionally,

his highlights a crucial difference between clinician- andechnician-performed ultrasounds. The Emergency Phy-icians performing these ultrasounds were subject to biasn that their knowledge of the patient’s clinical andiochemical parameters may have affected their decisiono diagnose cholecystitis on ultrasound. We maintain thathis lends itself to strengthen our findings, as the Emer-ency Physician’s interest lies with patient diagnosis andisposition, not the result of the test in isolation.

The sample size was small, and because we enrollednly patients with a positive ultrasound, sensitivity andpecificity cannot be calculated. The resulting PPV of4% similarly has a lower limit of the confidence intervalf 87%, which may be unacceptably low to some clini-ians. However, the reported sensitivity of ED ultra-ound is high, and assuming this to be true, the costavings estimated in this article are realistic.

An inherent limitation of our economic analysis ofpportunity cost is that we chose to evaluate only mon-tary costs directly associated with additional testing.here very well may be other forms of “cost” associatedith further radiological evaluations, or there may be

conomic and non-economic benefits to additional imaging.ormal cost-effectiveness analyses should be conducted toore appropriately address this question. Additionally, any

ypothetical financial or human resources saved by the usef REMP-performed ultrasound must be transferable to theerformance of another service for the health care system toealize a benefit. In other words, any money or time savedn the treatment of these patients must be utilized to satisfynother financial or labor demand; otherwise, the system aswhole may experience a net revenue loss. Although this

iscussion is beyond the scope of this manuscript, it is clearhat for any net savings to occur, changes in health careosts and resource utilization must be paralleled by alter-tions in subsequent reimbursement.

CONCLUSIONS

ased on this small sample, additional radiological testserformed subsequent to positive focused RUQ ED ul-rasounds by REMPs in the setting of acute cholecystitisesulted in significant economic costs to the health careystem. Whether or not these additional tests are redun-ant, these findings should prompt the examination ofur individual practice and the consideration that anydditional testing has the potential to impose a significantconomic burden on the health care system. Furthertudies, both prospective and retrospective, of the econ-my of this and other diagnostic algorithms, such as the

valuation of deep venous thrombosis, are warranted.

Uto

1

1

1

1

Opportunity Cost of Additional Radiographic Studies Following Bedside Diagnosis of Cholecystitis 651

ltimately, this may enable us to save significant quan-ities of health care dollars without sacrificing the qualityf care provided.

REFERENCES

1. CDC National Center for Health Care Statistics. Available at.www.cdc.gov/nchs/fastats/ervisits.htm. Accessed November 9,2007.

2. Alobaidi M, Gupta R, Jafri SZ, et al. Current trends in imagingevaluation of acute cholecystitis. Emerg Radiol 2004;10:256–8.

3. American College of Radiology Appropriateness Criteria. Avail-able at. http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonGastrointestinalImaging/RightUpperQuadrantPainDoc13.aspx. Accessed November 9,2007.

4. Kalimi R, Gecelter GR, Caplin D, et al. Diagnosis of acute cho-lecystitis: sensitivity of sonography, cholescintigraphy, and com-bined sonography-cholescintigraphy. J Am Coll Surg 2001;193:609–13.

5. Jehle D, Davis E, Evans T, et al. Emergency department sonogra-

phy by emergency physicians. Am J Emerg Med 1989;7:605–11.

6. Rosen CL, Brown DF, Chang Y, et al. Ultrasonography by emer-gency physicians in patients with suspected cholecystitis. Am JEmerg Med 2001;19:32–6.

7. Kendall JL, Shimp RJ. Performance and interpretation of focusedright upper quadrant ultrasound by emergency physicians. J EmergMed 2001;21:7–13.

8. Hsiao WC, Braun P, Yntema D, et al. Estimating physicians’ workfor a resource-based relative-value scale. N Engl J Med 1988;319:835–41.

9. Hsiao WC, Braun P, Dunn D, et al. Results and policy implicationsof the resource-based relative-value study. N Engl J Med 1988;319:881–8.

0. US Census Bureau. American Community Survey (ACS). 2003ACS Tabular Profile for Nassau County. Available at: http://www.census.gov/acs/www/Products/Profiles/Single/2003/ACS/Tabular/050/05000US360591.htm. Accessed November 9, 2007.

1. Yusoff IF, Barkun JS, Barkun AN. Diagnosis and management ofcholecystitis and cholangitis. Gastroenterol Clin North Am 2003;32:1145–68.

2. Palmer S, Raftery J. Economic notes: opportunity cost. BMJ 1999;318:1551–2.

3. Mark DB, Hlatky MA, Califf RM, et al. Cost effectiveness ofthrombolytic therapy with tissue plasminogen activator as com-pared with streptokinase for acute myocardial infarction. N Engl

J Med 1995;332:1418–24.

ARTICLE SUMMARY1. Why is this topic important?

Accurate, emergent diagnosis of acute cholecystitisdecreases morbidity and mortality. Increasingly, Emer-gency Physicians are utilizing ultrasound imaging toevaluate for cholecystitis in their daily practice.2. What does this study attempt to show?

We attempt to evaluate the economic costs of addi-tional radiographic testing after positive identification ofacute cholecystitis by Emergency Department (ED) ul-trasound, and extrapolate these costs to a local and na-tional level.3. What are the key findings?

In this small sample of consecutive “positive” cases ofacute cholecystitis diagnosed via ultrasound by RDMS-certified/eligible Emergency Physicians, 75% of patientsreceived additional radiological testing. As a result, anadditional cost of $6885 was incurred at our hospital overa 9-month period. Using nationally recognized Medicarecompensation indices, this “opportunity” cost was extrap-olated to approximately $63 million/year (CI) for theUnited States, assuming that 50% of cholecystitis patientspresent to the ED for evaluation.4. How is patient care impacted?

Our results suggest that additional radiological testingsubsequent to ED ultrasound identification of cholecys-titis may represent a potential financial burden on thehealth care system. Further research should evaluate theaccuracy and full economic impact of ED ultrasound usein cholecystitis and other disease states to improve pa-tient care and optimize health care resource utilization.