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Measure Summary
Title
Imaging efficiency: percentage of abdomen CT studies that are performed with and without contrast out of all abdomen CT studies performed.
Source(s)
Centers for Medicare & Medicaid Services (CMS). Specifications manual for hospital outpatient department quality measures (v 5.1a). Baltimore (MD): Centers for Medicare & Medicaid Services (CMS); 2011 Dec. various p.

OP-10: abdomen CT use of contrast material. Baltimore (MD): Centers for Medicare & Medicaid Services (CMS); 2012 Apr. 2 p.

Measure Domain

Primary Measure Domain
Clinical Efficiency Measures: Efficiency
Secondary Measure Domain
Clinical Quality Measure: Process

Brief Abstract

Description

This measure is used to assess the percentage of abdomen computed tomography (CT) studies performed with and without contrast ("combined studies") out of all abdomen CT studies performed (those with contrast, those without contrast, and those with both). As of January 1, 2011, the Centers for Medicaid & Medicare Services (CMS) changed the way abdomen and pelvis CT scans performed together are coded. Although the original codes for abdomen and pelvis CT scans conducted separately still exist, CMS now mandates that services performed together at least 75 percent of the time must use one Current Procedure Terminology (CPT) code. Assigning one code in these instances is the agency's way of eliminating what it considers double payments for similar scans conducted at the same time. Beginning in 2013, the calculation and public reporting of this measure reflects this coding change.

The measure is calculated based on a one-year window of claims data.

Rationale

Abdomen computed tomography (CT) is a very common advanced imaging procedure in the Medicare population. All three CT abdomen procedures (those with contrast, those without contrast, and those with both) were in the top 30 most common advanced imaging procedures in the 2006 Medicare claims outpatient data. This measure calculates the percentage of abdomen studies that are performed with and without contrast out of all abdomen studies performed (i.e., those with contrast, those without contrast, or those with both). The intent of this measure is to assess questionable utilization of contrast agents that carry an element of risk and significantly increase examination cost. While there may be a direct financial benefit to the service provider for the use of contrast agents due to increased reimbursements for "combined" studies, this proposed measure is directed at the identification of those providers who typically employ interdepartmental/facility protocols that call for its use in nearly all cases. The measure identifies prevailing norms for the use of combined studies, as well as the providers that vary substantially from the norms, to document possible inefficient examination protocols.

The measure seeks to promote the use of studies that are considered reasonable for the indication, while avoiding potentially harmful effects of unnecessary radiation and contrast exposure. The mistaken concept is that more information is always better. A combined computed axial tomography (CT) study essentially doubles the radiation dose to the patient and exposes him/her to the potential harmful side effects of the contrast material itself. Further, Medicare claims analyses show that a significant pattern of variation among high volume providers exists in the use of combination examinations in conjunction with CT abdomen.

Evidence for Rationale
CT abdomen with and without contrast material. Baltimore (MD): Centers for Medicare & Medicaid Services (CMS); 13 p.
Primary Health Components

Abdomen computed tomography (CT); contrast material; combined studies

Denominator Description

The number of abdomen computed tomography (CT) studies performed (with contrast, without contrast or both with and without contrast) (see the related "Denominator Inclusions/Exclusions" field)

Numerator Description

The number of abdomen computed tomography (CT) studies with and without contrast (combined studies) (see the related "Numerator Inclusions/Exclusions" field)

Evidence Supporting the Measure

Type of Evidence Supporting the Criterion of Quality for the Measure
  • A clinical practice guideline or other peer-reviewed synthesis of the clinical research evidence
  • One or more research studies published in a National Library of Medicine (NLM) indexed, peer-reviewed journal
Additional Information Supporting Need for the Measure
  • In a retrospective observational analysis of computed tomography (CT) scanning patterns of use and dose, researchers investigate trends in CT utilization, including the use of contrast material and repeat procedures on the same day. The study finds that 93% of CT abdomen scans performed between 1990 and 1999 were done with intravenous contrast. The remaining 7% not using intravenous contrast were primarily done for evaluation of renal or ureteral calculi, a finding that is consistent with the rationale for the exclusion criteria in our measure. Additionally, for patients having CT abdomen scans, 96% had more than one scan sequence on the same day. The findings of this study are of concern as they indicate a high use of potentially hazardous contrast material and overutilization and duplicative use of imaging services related to CT abdomen.
  • Three studies investigated different contrast materials in different organ systems. The relevant randomized controlled trial (RCT) compared the use of water to a dilute suspension of collagen as contrast media for imaging when disease is suspected within the stomach or proximal duodenum. This study found significantly more artifacts were caused by the use of water as contrast media than dilute collagen and recommended the use of a dilute suspension of collagen as contrast media when disease is suspected within the stomach or proximal duodenum.
  • An additional clinical trial investigated the induction of clinically relevant changes in thyroid function parameters of euthyroid patients as a result of iodine-containing contrast media by measuring mean thyroid stimulating hormone levels (TSH). The study found iodine-containing contrast media can induce transient subclinical hypothyroidism in euthyroid patients; however, TSH reaction seems to be dependent on the preexisting state of thyroid function.
  • A final review provided an overview of the potential advantages of using low-osmolar iodinated solutions as an oral contrast agent for CT abdomen studies. The study indicated iohexol may be an alternative to high-osmolar iodinated solutions or barium sulfate suspensions in certain clinical indications due to high frequency of nausea, vomiting, diarrhea and other adverse events as a result of the latter two contrast materials.

See also "CT Abdomen With and Without Contract Material" for a targeted literature review using relevant computed tomography (CT), abdomen and contrast media search terms.

Evidence for Additional Information Supporting Need for the Measure
CT abdomen with and without contrast material. Baltimore (MD): Centers for Medicare & Medicaid Services (CMS); 13 p.

Gartner W, Weissel M. Do iodine-containing contrast media induce clinically relevant changes in thyroid function parameters of euthyroid patients within the first week. Thyroid. 2004 Jul;14(7):521-4. PubMed External Web Site Policy

Horton KM, Fishman EK, Gayler B. The use of iohexol as oral contrast for computed tomography of the abdomen and pelvis. J Comput Assist Tomogr. 2008 Mar-Apr;32(2):207-9. PubMed External Web Site Policy

Mettler FA Jr, Wiest PW, Locken JA, Kelsey CA. CT scanning: patterns of use and dose. J Radiol Prot. 2000 Dec;20(4):353-9. PubMed External Web Site Policy

Ramsay DW, Markham DH, Morgan B, Rodgers PM, Liddicoat AJ. The use of dilute Calogen as a fat density oral contrast medium in upper abdominal computed tomography, compared with the use of water and positive oral contrast media. Clin Radiol. 2001 Aug;56(8):670-3. PubMed External Web Site Policy
Extent of Measure Testing

Unspecified

State of Use of the Measure

State of Use
Current routine use
Current Use
External oversight/Medicare
Internal quality improvement
Pay-for-reporting
Public reporting

Application of the Measure in its Current Use

Measurement Setting
Ambulatory/Office-based Care
Hospital Outpatient
Professionals Involved in Delivery of Health Services
Does not apply to this measure (e.g., measure is not provider specific)
Least Aggregated Level of Services Delivery Addressed
Single Health Care Delivery or Public Health Organizations
Statement of Acceptable Minimum Sample Size
Unspecified
Target Population Age

Unspecified

Target Population Gender
Either male or female

National Strategy for Quality Improvement in Health Care

National Quality Strategy Aim
Affordable Care
National Quality Strategy Priority
Making Quality Care More Affordable
Prevention and Treatment of Leading Causes of Mortality

Institute of Medicine (IOM) National Health Care Quality Report Categories

IOM Care Need
Getting Better
IOM Domain
Effectiveness
Efficiency

Data Collection for the Measure

Case Finding Period

Encounter dates January 1 through June 30 and July 1 through December 31

Denominator Sampling Frame
Patients associated with provider
Denominator (Index) Event or Characteristic
Diagnostic Evaluation
Encounter
Denominator Time Window
Does not apply to this measure
Denominator Inclusions/Exclusions

Inclusions
The number of abdomen computed tomography (CT) studies performed (with contrast, without contrast or both with and without contrast)

Exclusions
Any patients with the following:

  • Unspecified disorder of kidney and ureter
  • Hematuria
  • Pancreatic disorders
  • Adrenal mass
  • Malignant neoplasms of liver and intrahepatic bile ducts
  • Neoplasms of the pancreas, kidney, and liver

Technical Note: An exclusion diagnosis must be in one of the diagnoses fields on the CT abdomen claim. If the diagnosis code is a 3-digit International Classification of Diseases, Ninth Revision (ICD-9) code, then all codes starting with the 3 digits are used in the measure calculation, i.e., "all inclusive." If the diagnosis code is specified as a 4-digit ICD-9 code, then only the specific four digit diagnosis code is used. If the diagnosis code is a 5-digit code, the code used is either the specific 5-digit diagnosis code if all 5 numeric digits are shown, or if the fifth digit is designated with an "X" then this is designating an "all inclusive" range to the 5th digit.

Refer to the original measure documentation for the ICD-9 and Current Procedural Terminology (CPT) codes.

Exclusions/Exceptions
Medical factors addressed
Numerator Inclusions/Exclusions

Inclusions
The number of abdomen computed tomography (CT) studies with and without contrast (combined studies)

Refer to the original measure documentation for the Current Procedural Terminology (CPT) codes.

Exclusions
Unspecified

Numerator Search Strategy
Fixed time period or point in time
Data Source
Administrative clinical data
Type of Health State
Does not apply to this measure
Instruments Used and/or Associated with the Measure

Unspecified

Computation of the Measure

Measure Specifies Disaggregation
Does not apply to this measure
Scoring
Rate/Proportion
Interpretation of Score
Desired value is a lower score
Allowance for Patient or Population Factors
Unspecified
Standard of Comparison
External comparison at a point in, or interval of, time
External comparison of time trends
Internal time comparison

Identifying Information

Original Title

OP-10: imaging efficiency measure: abdomen CT use of contrast material.

Measure Set Name
Submitter
Centers for Medicare & Medicaid Services - Federal Government Agency [U.S.]
Developer
Centers for Medicare & Medicaid Services - Federal Government Agency [U.S.]
Funding Source(s)

United States Department of Health and Human Services

Composition of the Group that Developed the Measure

Centers for Medicare & Medicaid (CMS) Contractor

Financial Disclosures/Other Potential Conflicts of Interest

None

Measure Initiative(s)
Hospital Compare
Hospital Outpatient Quality Reporting Program
Adaptation

This measure was not adapted from another source.

Date of Most Current Version in NQMC
2011 Dec
Measure Maintenance

Unspecified

Date of Next Anticipated Revision

2013 Jan 1

Measure Status

Please note: This measure has been updated. The National Quality Measures Clearinghouse is working to update this summary.

Source(s)
Centers for Medicare & Medicaid Services (CMS). Specifications manual for hospital outpatient department quality measures (v 5.1a). Baltimore (MD): Centers for Medicare & Medicaid Services (CMS); 2011 Dec. various p.

OP-10: abdomen CT use of contrast material. Baltimore (MD): Centers for Medicare & Medicaid Services (CMS); 2012 Apr. 2 p.
Measure Availability

The individual measure, "OP-10: Imaging Efficiency Measure: Abdomen CT Use of Contrast Material," is published in the "Hospital Outpatient Quality Reporting (OQR) Specifications Manual (Version 5.1a)." An update of this document is available from the QualityNet Web site External Web Site Policy. Check the QualityNet Web site regularly for the most recent version of the specifications manual and for the applicable dates of discharge.

NQMC Status

This NQMC summary was completed by ECRI Institute on August 29, 2012. The information was verified by the measure developer on November 26, 2012.

Copyright Statement

No copyright restrictions apply.

The Hospital Outpatient Quality Reporting (OQR) Specifications Manual (Version 5.1a) is periodically updated by the Centers for Medicare & Medicaid Services. Users of the Hospital OQR Specifications Manual must update their software and associated documentation based on the published manual production timelines.

Disclaimer

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The National Quality Measures Clearinghouse™ (NQMC) does not develop, produce, approve, or endorse the measures represented on this site.

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