Improving Mammography Performance in Practice

Patricia Carney, PhD
Professor of Family Medicine
Associate Director for Population Studies
Oregon Health & Science University Cancer Institute
Portland, Oregon

What's the problem?

Mammography is not a perfect test, partly because of the complex architecture of the breast tissue being imaged and partly because the technology is imperfect. Moreover, abnormalities are a rare event, with about 4 to 6 occurring in every 1,000 mammograms. Accurately reading and interpreting screening mammograms is therefore an important challenge for radiologists.

Shortcomings in human decision making, coupled with complicated practice settings, also influence physicians' interpretive performance. Despite the proven value of mammography, its efficacy depends in large part on radiologists' interpretative skills, and radiologists differ substantially in their interpretations.

Although previous studies have shown marked differences in radiologists' interpretive behavior, we still have much to learn about how to use that knowledge to maximize breast cancer screening performance in community settings. Key unanswered questions include: What factors influence radiologists' behavior as they read and interpret mammograms? What is the best way to systematically provide feedback to radiologists on their interpretive performance? What kinds of interventions could best help radiologists change their behavior to improve their interpretive performance, and ultimately, to improve screening mammography in community settings?

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How will this research address the problem?

In 1994, the National Cancer Institute established the Breast Cancer Surveillance Consortium (BCSC), a research resource for studies designed to assess the delivery and quality of breast cancer screening and related patient outcomes in the United States. The BCSC is a collaborative network of five mammography registries and two affiliated sites with linkages to pathology and/or tumor registries. The network is supported by a central Statistical Coordinating Center. As of May 2008, the Consortium's database contained information on more than 2 million women, 7.5 million screening mammographic examinations interpreted by more than 1,000 community radiologists, and 86,700 breast cancer cases.

Dr. Patty Carney, recently the principal investigator of the New Hampshire Mammography Network (one of the BCSC sites) and currently a professor at Oregon Health & Science University Cancer Institute, has long had an interest in physician behavior. In particular, she has been interested in understanding the factors that influence physician behavior and in using that knowledge to develop interventions aimed at improving performance. She has worked both with physicians in training and physicians in practice.

The BCSC has provided a rich harvest of data that Dr. Carney and investigators at the other BCSC sites have used to understand the factors that influence radiologist behavior. Studies using these data, for example, have shown extensive variability among radiologists in their interpretive performance and accuracy. This work also has noted great variability among existing audits, the reports that mammography facilities use to provide feedback to radiologists.

Since September 2000, Dr. Carney and investigators at three other BCSC sites have been collaborating with a team at Harborview Medical Center, in Seattle, led by Dr. Joann Elmore on a project called Factors Affecting Variability of Radiologists (FAVOR). FAVOR has used data from the BCSC registries in New Hampshire, Colorado, North Carolina, and Washington State and a survey of radiologists to estimate the accuracy of mammography at an individual level and to better understand the reasons for variability in interpretation.

Using the BCSC registry data and the results from the radiologist survey, Drs. Carney and Elmore and their research teams have developed and are now testing an interactive web-based educational intervention. This intervention is designed to help radiologists examine and understand their interpretive performance over time and determine whether and how they can improve their own accuracy. When a radiologist logs onto the system, the intervention automatically populates all fields with his or her individual data.

The FAVOR web-based intervention has three modules. Module 1, Outcome Audits, explains the basic components of an radiologist audit report (i.e., screening results, recall rates, biopsy yields, sensitivity, and specificity), and allows users to compare their own audit results with the average results of other US radiologists and with national benchmarks established by the Agency for Healthcare Research and Quality. Module 2, The Influence of Breast Cancer Risk Perceptions on Mammography Interpretation, helps radiologists learn the breast cancer risk factors of pre- and post-menopausal women whose mammograms they have interpreted, assess how their interpretive performance may be influenced by perceptions of risk, and consider whether to change their clinical practice once breast cancer risk is clarified. Module 3, Malpractice and Mammography, helps radiologists learn the prevalence of medical malpractice suits among radiologists who interpret mammograms, understand how perception of this risk is higher than actual risk, and assess whether malpractice concerns influence their practice.

The study is a randomized controlled trial with an early group of radiologists undertaking the intervention first, and a late group serving as a control group. Currently, the study is in the 9-month window between implementation of the early group and the late group. In January 2009, the late group will receive the intervention and data analysis will begin shortly thereafter.

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Significance of the study and results

Breast cancer is a significant cause of morbidity and mortality in the United States. Until it can be prevented, the best approach includes mammography screening for early detection. A better understanding of ways to enhance radiologists' mammography interpretive performance is needed to optimize the impact of mammography screening.

One of the distinguishing features of this work is that it takes advantage of a large, multi-site surveillance research resource, the BCSC, to develop a web-based intervention that can directly influence the practice patterns of radiologists in community practice through its predisposing, enabling, and reinforcing elements. This program predisposes radiologists to change (by helping them understand current levels of performance and their goals for achievement), enables change (by facilitating a revision of how they use audit reports to change practice), and reinforces change (by providing support to ensure the enabling components occur). Whether it actually results in change is important, because many new imaging technologies are on the horizon. To the extent that they rely on interpretive behavior of humans, we need to show that behavior can optimized if we hope to achieve the potential impact of the old as well as new technologies.

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Recent publications of interest

Taplin S, Abraham L, Barlow WE, Fenton JJ, Berns EA, Carney PA, Cutter GR, Sickles EA, Carl D, Elmore JG. Mammography facility characteristics associated with interpretive accuracy of screening mammography. J Natl Cancer Inst 2008 Jun 18;100(12):876-87.

Baernstein A, Liss HK, Carney PA, Elmore JG. Trends in study methods used in undergraduate medical education research, 1969-2007. JAMA 2007 Sep 5;298(9):1038-45. Review.

Carney PA, Yi JP, Abraham LA, Miglioretti DL, Aiello EJ, Gerrity MS, Reisch L, Berns EA, Sickles EA, Elmore JG. Reactions to uncertainty and the accuracy of diagnostic mammography. J Gen Intern Med 2007 Feb;22(2):234-41.

Miglioretti DL, Smith-Bindman R, Abraham L, Brenner RJ, Carney PA, Bowles EJ, Buist DS, Elmore JG. Radiologist characteristics associated with interpretive performance of diagnostic mammography. J Natl Cancer Inst 2007 Dec 19;99(24):1854-63.

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Last modified:
10 Nov 2008
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