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  • Guideline Summary
  • NGC:010405
  • 2013 Oct-Dec

The official positions of the International Society for Clinical Densitometry: acquisition of dual-energy x-ray absorptiometry body composition and considerations regarding analysis and repeatability of measures.

Hangartner TN, Warner S, Braillon P, Jankowski L, Shepherd J. The official positions of the International Society for Clinical Densitometry: acquisition of dual-energy x-ray absorptiometry body composition and considerations regarding analysis and repeatability of measures. J Clin Densitom. 2013 Oct-Dec;16(4):520-36. [68 references] PubMed External Web Site Policy

This is the current release of the guideline.

Major Recommendations

The definitions for quality of evidence (Good, Fair, Poor), strength of recommendations (A–C), and application of recommendations (W, L) are provided at the end of the "Major Recommendations" field.

Accuracy and Precision Assessment

Questions

  • What phantoms and procedures should be used for quality control (QC) monitoring and cross-calibration for whole-body outcomes?
    • What phantoms should be used to assure a dual-energy X-ray absorptiometry (DXA) system is working within specifications and with stable calibration over time?
    • How can measures be cross-calibrated between systems from different manufacturers?
    • How to cross-calibrate measures between systems of the same manufacturer?
  • How should the accuracy of percent fat, fat mass, and lean mass be ascertained in the clinical setting?
    • What phantoms are available to ascertain absolute accuracy?

International Society for Clinical Densitometry (ISCD) Official Position

  • No phantom has been identified to remove systematic difference in body composition when comparing in vivo results across manufacturers. Grade: Good-B-W
  • An in vivo cross-calibration study is necessary when comparing in vivo results across manufacturers. Grade: Fair-B-W
  • Cross-calibrating systems of the same make and model can be performed with an appropriate phantom. Grade: Fair-A-W
  • Changes in body composition measures can be evaluated between 2 different systems of the same make and model if the systems have been cross-calibrated with an appropriate total-body phantom. Grade: Fair-B-W
  • When changing hardware, but not the entire system, or when replacing a system with the same technology (make and model), cross-calibration should be performed by having one technologist do 10 phantom scans, with repositioning, before and after hardware change. If a >2% difference in mean percent fat, fat mass, or lean mass is observed, contact the manufacturer for service/correction. Grade: Fair-B-W
  • No total-body phantoms are available at this time that can be used as absolute reference standards for soft-tissue composition or bone mineral mass. Grade: Good-A-W
  • The QC program at a DXA body composition facility should include compliance with manufacturer guidelines for system maintenance. In addition, if not recommended in the manufacturer protocol, the following QC procedures are advised: Grade: Fair-B-W
    • Perform periodic (at least once per week) body composition QC scans for any DXA system as an independent assessment of system calibration.
    • Plot and review data from calibration and body composition QC scans.
    • Verify the body composition phantom mean percent fat mass and tissue mass after any service performed on the densitometer.
    • Establish and enforce corrective action thresholds that trigger a call for service.
    • Maintain service logs.
    • Comply with radiation surveys and regulatory government inspections, radiation surveys, and regulatory requirements.

Acquisition of DXA Body Composition Measures in Patients

Questions

  • What is the optimal way to prepare and position a patient for whole body scans?
    • How should the hands, arms, legs, and feet be positioned?
    • How should very obese or patients that do not fit within the scan limits be positioned?

ISCD Official Position

  • Consistent positioning and preparation (e.g., fasting state, clothing, time of day, physical activity, empty bladder) of the patient are important for precise measures. Grade: Fair-B-W
  • Positioning of the arms, hands, legs, and feet whenever possible should be according to the National Health and Nutrition Examination Survey (NHANES) method (palms down isolated from the body, feet neutral, ankles strapped, arms straight or slightly angled, face up with neutral chin). Grade: Fair-B-W
  • "Offset scanning" should be used in patients who are too wide to fit within the scan boundaries, using a validated procedure for a specific scanner model. Grade: Fair-B-W

Considerations Regarding Analysis and Repeatability of Measures

Questions

  • How should whole body scans be analyzed?
    • How should arms, legs, and head be sectioned from the trunk?
    • If observed in the scan at the time of analysis, how should removable artifacts be addressed?
    • If observed in the scan at the time of analysis, how should nonremovable artifacts be addressed?
  • How should precision be assessed for body composition measures?
  • What is the minimum precision acceptable for a DXA site?
    • What is the minimum precision for fat tissue assessment?
    • What is the minimum precision for lean tissue assessment?

ISCD Official Position

  • Every technologist should perform an in vivo precision assessment for all body composition measures of interest using patients who are representative of the clinic's patient population. Grade: Fair-B-W
  • The minimum acceptable precision for an individual technologist is 3%, 2%, and 2% for fat mass, lean mass, and percent fat, respectively. Grade: Fair-B-W
  • Consistently use manufacturers' recommendations for region of interest (ROI) placement. Grade: Fair-B-W
  • Consistently use manufacturers' recommendations for artifact removal. Grade: Fair-B-W

Definitions:

Quality of Evidence

Good: Evidence includes consistent results from well-designed, well-conducted studies in representative populations.

Fair: Evidence is sufficient to determine effects on outcomes, but the strength of the evidence is limited by the number, quality, or consistency of the individual studies.

Poor: Evidence is insufficient to assess the effects on outcomes because of limited number or power of studies, important flaws in their design or conduct, gaps in the chain of evidence, or lack of information.

Strength of Recommendations

A: Strong recommendation supported by the evidence

B: Recommendation supported by the evidence

C: Recommendation supported primarily by expert opinion

Application of Recommendations

W: Worldwide recommendation

L: Application of recommendation may vary according to local requirements

Clinical Algorithm(s)

None provided

Disease/Condition(s)

  • Sarcopenia
  • Obesity

Guideline Category

Diagnosis

Evaluation

Risk Assessment

Technology Assessment

Clinical Specialty

Endocrinology

Family Practice

Geriatrics

Internal Medicine

Obstetrics and Gynecology

Radiology

Rheumatology

Intended Users

Physicians

Guideline Objective(s)

  • To outline the new 2013 International Society for Clinical Densitometry Official Positions regarding acquisition of body composition analysis using dual energy x-ray absorptiometry (DXA)
  • To review the literature, summarize the relevant findings, and formulate positions covering (1) accuracy and precision assessment, (2) acquisition of DXA body composition measures in patients, and (3) considerations regarding analysis and repeatability of measures

Target Population

Individuals at risk of very low lean body mass, very low fat mass, or very high fat mass (either regionally or systemically)

Interventions and Practices Considered

  1. Accuracy and precision assessment
    • Phantoms and procedures for quality control (QC) monitoring and cross-calibration for whole-body outcomes
    • Use of phantoms for ascertaining accuracy of percent fat, fat mass, and lean mass
  2. Acquisition of dual-energy x-ray absorptiometry (DXA) body composition measures
    • Optimal patient positioning
    • Positioning very obese patients
  3. Considerations regarding analysis and repeatability of measures

Major Outcomes Considered

  • Adequacy and utility of body composition phantoms for scanner cross-calibration
  • Precision of body composition parameters (percent fat, fat mass, lean mass) measured by dual-energy x-ray absorptiometry (DXA)

Methods Used to Collect/Select the Evidence

Searches of Electronic Databases

Description of Methods Used to Collect/Select the Evidence

Task Force members performed a medical literature search relevant to the clinical and/or technical questions using a method modified from that utilized by the Cochrane reviews. The literature searches were conducted using electronic databases from 1/1/1990 through 12/31/2012.

A total of 8 literature searches were performed in PubMed, with major key words related to dual-energy x-ray absorptiometry (DXA) whole-body phantoms, fat tissue accuracy and precision, lean tissue accuracy and precision, region definition and analysis procedures, artifacts, and measurement frequency (see Appendix A in the original guideline document for specific search strategies). The searches yielded approximately 200 citations, and all these papers were downloaded and distributed to the task force for review and assessment of relevance to the questions at hand.

Number of Source Documents

The searches yielded approximately 200 citations.

Methods Used to Assess the Quality and Strength of the Evidence

Weighting According to a Rating Scheme (Scheme Given)

Rating Scheme for the Strength of the Evidence

Quality of Evidence

Good: Evidence includes consistent results from well-designed, well-conducted studies in representative populations.

Fair: Evidence is sufficient to determine effects on outcomes, but the strength of the evidence is limited by the number, quality, or consistency of the individual studies.

Poor: Evidence is insufficient to assess the effects on outcomes because of limited number or power of studies, important flaws in their design or conduct, gaps in the chain of evidence, or lack of information.

Methods Used to Analyze the Evidence

Review of Published Meta-Analyses

Systematic Review

Description of the Methods Used to Analyze the Evidence

The development of the International Society for Clinical Densitometry (ISCD) Official Positions was undertaken according to the RAND/University of California, Los Angeles (UCLA) Appropriateness Method (RAM). This is a mechanism to determine whether procedures or indications are expected to provide a specific health benefit, designated as "appropriate," that exceeds the potential negative consequences by such a wide margin that the procedure or indication is worth doing, exclusive of cost. The rationale for use of the RAM for the Position Development Conference (PDC) is based on its ability to combine the best available scientific evidence with the collective judgment of worldwide experts in the bone field, to yield appropriate recommendations that are patient- and technology-specific.

Methods Used to Formulate the Recommendations

Expert Consensus (Consensus Development Conference)

Description of Methods Used to Formulate the Recommendations

Position Development Conference (PDC) Expert Panel

Concurrent with Task Force work, international experts in the field of bone densitometry and societies specific to skeletal health were contacted by the PDC Steering Committee to serve as member panelists. Twelve experts agreed to participate on the PDC Expert Panel. In addition to individuals representing many regions of the world, one official representative from each of the following professional societies were participants on the expert panel: The American Society for Bone and Mineral Research (ASBMR), the North American Menopause Society (NAMS), and the National Osteoporosis Foundation (NOF). The role of the Expert Panel was to review the proposed Official Positions and supportive documents developed by the task forces and make final recommendations to the International Society for Clinical Densitometry Board of Directors (ISCD BOD).

PDC Moderators

PDC panel Moderators with experience in the RAND/University of California, Los Angeles (UCLA) Appropriateness Method (RAM) were selected by the Steering Committee. Two moderators assisted the Chair of the PDC in the development and refinement of statements derived from the initial Task Forces questions and sub-questions and, along with the Chair of the PDC, lead the discussion and the rating by the Expert Panel during the PDC in Tampa, Florida, USA.

Grading of the Official Positions

All Official Positions for the 2013 PDC were rated by the Expert Panel in the following categories: appropriateness, necessity, quality of evidence, strength of recommendations and application of recommendations (see the "Rating Scheme for the Strength of the Evidence" and the "Rating Scheme for the Strength of the Recommendations" fields).

Proposed ratings in all cases, except the RAM ratings for appropriateness and necessity for each of the above categories, were included in the preliminary Official Positions crafted by each Task Force. Final ratings were determined by the on site meeting, convened Expert Panel that included appropriateness and necessity.

A rating of "appropriate" was required in order for a statement to be sent to the BOD for selection as an ISCD Official Position. Ratings of each Official Position from the 2013 PDC are expressed in the form of four characters representing quality of the evidence, strength of the recommendation, application of the recommendation, and whether it is necessary as previously described. For example, a rating "Good-A-W-Necessary" indicates that the evidence includes consistent results from well-designed, well-conducted studies in representative populations, a strong recommendation supported by the evidence, worldwide recommendation, and is necessary to perform in all instances. Since PDC topics are often selected because strong medical evidence is unavailable, it is the nature of the process that Official Positions are not always supported by the highest possible level of evidence. Nevertheless, the ISCD Official Positions encourage consistent approaches in the clinical practice of bone densitometry, and focus attention on issues that require further study.

PDC Procedures

After the initial selection of topics by the Board of Directors and Scientific Advisory Committee, the PDC Steering Committee selected three Task Force chairpersons, one for each of the three major PDC topics. Thereafter, the PDC Steering Committee and Task Force chairpersons worked collectively to select international experts as members of their respective Task Forces with the knowledge required to evaluate their assigned PDC topic. All topic questions and sub-questions that were generated by each Task Force were thoroughly researched in the scientific medical literature.

Prior to the PDC meeting in Tampa, Florida, USA, topic questions and sub-questions were converted into recommendation statements that were sent to the Expert Panel for an initial "appropriateness" rating. The PDC required a median "appropriateness" rating in either the upper third or lower third of the rating continuum (continuum was 1 to 9 with clusters 7 to 9 representing the upper third and clusters 1 to 3 representing the lower third) without "disagreement." "Disagreement" was defined as lack of consensus being predetermined to be four or more Expert Panelists rating in extreme clusters 1 to 3 and 7 to 9. In circumstances where the median "appropriateness" rating was less than 7, no Official Position was developed.

In making its decisions, the Expert Panel considered the level of the medical evidence, expert opinion, and the clinical need for a recommendation. In some instances, regulatory issues received consideration. The statements rated as "appropriate" with a median score of 7 or higher without "disagreement" by the Expert Panel were designated Official Positions. The statements rated as "uncertain" with a median score between four and six or any median score with "disagreement" were further discussed at the PDC. After the initial rating the documents supporting all Task Forces' recommendations were sent to the Expert Panelists for review. In brief, Task Force chairs presented reports on their topics supporting the "uncertain" statements to the Expert Panelists in closed session on the first day of the conference. These statements were then edited by Task Force chairs, if necessary, reflecting suggestions made by the Expert Panelists. Re-rating of "uncertain" statements occurred during each Task Force chairpersons' presentation when the PDC Moderators felt there was a significant likelihood of change in the opinions of the Expert Panel.

After all statements rated as "appropriate without disagreement" had been selected and all supporting evidence presented, the Expert Panel performed a final rating for necessity, quality of the evidence, strength of the recommendation, and application of the recommendation. The proposed Official Positions with supportive evidence were presented by the Task Force chairs at a meeting open to the public (in conjunction with the ISCD Annual Meeting) and attended by ISCD members, representatives from companies with interests in bone health and skeletal assessment, and other individuals with interest in bone disease and densitometry. All participants were encouraged to provide comments and suggestions to the expert panelists. On the next day, the Expert Panelists, in closed session, determined final wording of the proposed Official Positions.

Rating Scheme for the Strength of the Recommendations

All Official Positions for the 2013 Position Development Conference were rated by the Expert Panel in the following categories:

Appropriateness: Statements that the Expert Panel rated as "appropriate without disagreement" according to predefined criteria derived from the RAND/University of California, Los Angeles (UCLA) Appropriateness Method (RAM) were referred to the International Society for Clinical Densitometry Board of Directors (ISCD BOD) with a recommendation to become ISCD Official Positions. A statement was defined as "appropriate" when the expected health benefit exceeded the expected negative consequences by a significant margin such that it was worth performing.

Necessity: Recommended Official Positions that were rated by the Expert Panel were then rated according to necessity to perform in all circumstances, i.e., whether the health benefits outweighed the risks to such an extent that it must be offered to all patients. Necessity rating was conducted in a similar fashion as the appropriateness rating, in that each Official Position had to be rated as necessary without disagreement using similar predefined RAM criteria.

Strength of Recommendations

A: Strong recommendation supported by the evidence

B: Recommendation supported by the evidence

C: Recommendation supported primarily by expert opinion

Application of Recommendations

W: Worldwide recommendation

L: Application of recommendation may vary according to local requirements

Cost Analysis

A formal cost analysis was not performed and published cost analyses were not reviewed.

Method of Guideline Validation

External Peer Review

Internal Peer Review

Description of Method of Guideline Validation

The proposed Official Positions with supportive evidence were presented by the Task Force chairs at a meeting open to the public and attended by International Society for Clinical Densitometry (ISCD) members, representatives from companies with interests in bone health and skeletal assessment, and other individuals with interest in bone disease and densitometry. All participants were encouraged to provide comments and suggestions to the expert panelists. On the final day, the Expert Panelists, in closed session, determined final wording of the proposed Official Positions.

Following completion of the Position Development Conference, the Steering Committee finalized recommendation wording without changing content. These recommendations were then presented to the International Society for Clinical Densitometry Board of Directors (ISCD BOD) for review and voting. The BOD did not alter the content or wording of the proposed Official Positions. Recommendations approved by a majority vote of the ISCD BOD became ISCD Official Positions.

Type of Evidence Supporting the Recommendations

The type of supporting evidence is specifically stated for each recommendation (see the "Major Recommendations" field).

Since the field of bone densitometry is new and evolving, some clinically important issues that are addressed at the Position Development Conferences are not associated with robust medical evidence. Accordingly some Official Positions are based largely on expert opinion.

Potential Benefits

  • Identification of those with localized or systemic loss of lean body mass warranting intervention
  • Identification of those with localized fat atrophy warranting intervention
  • Specification, among those with a high body mass index, of the proportions of body mass that are lean tissue and adipose tissue

Potential Harms

Low radiation exposure

Qualifying Statements

Since Position Development Conference topics are often selected because strong medical evidence is unavailable, it is the nature of the process that Official Positions are not always supported by the highest possible level of evidence. Nevertheless, the International Society for Clinical Densitometry (ISCD) Official Positions encourage consistent approaches in the clinical practice of bone densitometry, and focus attention on issues that require further study.

Description of Implementation Strategy

An implementation strategy included publication of the International Society for Clinical Densitometry (ISCD) Official Positions in international journals that directly or indirectly pertain to skeletal diseases and the measurement of skeletal health.

Formal presentation of the ISCD Official Positions occurs at ISCD Annual Scientific Meetings, all ISCD Adult and Pediatric Bone Density Educational Courses, and ISCD Vertebral Fracture Assessment Educational courses. The Official Positions have been published in the society's official journal, Journal of Clinical Densitometry and Assessment of Skeletal Health.

Implementation Tools

Foreign Language Translations

Quick Reference Guides/Physician Guides

Staff Training/Competency Material

For information about availability, see the Availability of Companion Documents and Patient Resources fields below.

IOM Care Need

Living with Illness

Staying Healthy

IOM Domain

Effectiveness

Bibliographic Source(s)

Hangartner TN, Warner S, Braillon P, Jankowski L, Shepherd J. The official positions of the International Society for Clinical Densitometry: acquisition of dual-energy x-ray absorptiometry body composition and considerations regarding analysis and repeatability of measures. J Clin Densitom. 2013 Oct-Dec;16(4):520-36. [68 references] PubMed External Web Site Policy

Adaptation

Not applicable: The guideline was not adapted from another source.

Date Released

2013 Oct-Dec

Guideline Developer(s)

International Society for Clinical Densitometry - Nonprofit Organization

Source(s) of Funding

International Society for Clinical Densitometry

Guideline Committee

Acquisition of Body Composition Analysis Studies Using DXA Task Force 2

Composition of Group That Authored the Guideline

Task Force Members: Thomas N. Hangartner, PhD (Chair), BioMedical Imaging Laboratory, Wright State University, Dayton, OH, USA; Sarah Warner, PhD, CCD, Perceptive Informatics, Billerica, MA, USA; Pierre Braillon, MD, PhD, Département de Radiologie, Hôpital Femme-Mére-Enfant, Lyon, France; Larry Jankowski, CBDT, Illinois Bone and Joint Institute, LLC, Morton Grove, IL, USA; John Shepherd, PhD, CCD, Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, USA

Financial Disclosures/Conflicts of Interest

None disclosed

Guideline Status

This is the current release of the guideline.

Guideline Availability

Electronic copies: Available to subscribers from the Journal of Clinical Densitometry Web site External Web Site Policy.

Print copies: Available from the International Society for Clinical Densitometry, 101 Centerpoint Drive, Suite 208, Middletown, CT 06457; Phone: (860) 259-1000; Fax: (860) 259-1030; Web site: www.iscd.org External Web Site Policy.

Availability of Companion Documents

The following are available:

Patient Resources

None available

NGC Status

This NGC summary was completed by ECRI Institute on August 21, 2014. The information was verified by the guideline developer on September 30, 2014.

Copyright Statement

This summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.

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