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REVIEWS AND COMMENTARY 䡲 OPINION Note: This copy is for your personal non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, contact us at www.rsna.org/rsnarights. Comparative Effectiveness Research: What It Means for Radiology1 Pari V. Pandharipande, MD, MPH G. Scott Gazelle, MD, MPH, PhD Published online 10.1148/radiol.2533091286 Radiology 2009; 253:600 – 605 1 From the Department of Radiology, Institute for Technology Assessment, Massachusetts General Hospital, 101 Merrimac St, 10th Floor, Boston, MA 02114. Received July 16, 2009; revision requested August 13; revision received August 25; final version accepted August 25. Address correspondence to P.V.P. (e-mail: pari@mgh -ita.org). Authors stated no financial relationship to disclose. 姝 RSNA, 2009 600 D iagnostic imaging is an important and costly component of medical care. In 2007, Medicare expenditures for imaging services totaled $11.4 billion; this represented a substantial increase from the $8.4 billion spent in 2002 (1). As the debate about health care reform has accelerated, further attention has been focused on the need to carefully assess the benefits and costs of imaging. In particular, there has been concern that expensive imaging tests often have been ordered and performed without sufficient evidence to support their appropriateness or potential benefits (2,3). For example, in a recent article in the New England Journal of Medicine, Avorn argued that currently, there is “almost no evidentiary bar at all” to gain Food and Drug Administration approval of imaging technologies (4). The problem is not inattention to research: In the past 2 decades, advances in radiology have soared, due at least in part to an ever-expanding imaging research enterprise. However, studies in which researchers quantify the long-term effects of imaging on patient outcome remain sparse. A few challenges may explain this evidence gap (5). First, diagnostic test results are intermediate outcomes; they influence, but do not directly determine, patients’ health outcomes. Factors such as disease severity, treatment effectiveness, or system performance may modulate the effect of imaging on outcomes. Second, imaging technology is a moving target; techniques are developed, refined, and become obsolete quickly. This makes it difficult to conduct sufficiently large trials quickly enough to be relevant. Third, randomized controlled trials of imaging technologies present several challenges. Because the majority of diagnostic imaging tests have minimal or no adverse effects and because of the general perception among patients and physicians that more information leads to better care, it is often both practically and ethically difficult to withhold a diagnostic test from patients enrolled in a randomized trial. Furthermore, it is often the case that several tests or combinations of tests are potentially useful; however, comparing all of these tests with sufficient statistical power to detect meaningful differences in outcomes may require an extremely large trial that could take years to complete and be prohibitively costly. Even if such trials could be completed, the results may be confounded by advances in treatments, imaging technologies, or both. There has been no better time to address these challenges than now. The American Reinvestment and Recovery Act has recently placed patient-centered outcomes research, termed comparative effectiveness research (CER), at the forefront of funding priorities (3,4,6–12). In the next 2 years alone, $1.1 billion will be allocated specifically for CER and will be divided among the National Institutes of Health, the Agency for Healthcare Research and Quality, and the Office of the Secretary in the U.S. Department of Health and Human Services (6,7,11). Additional funds may be devoted to CER through the Challenge (RC1) and Grand Opportunity (RC2) grant mechanisms. The coming years will be an ideal time for investigators in radiology to develop a CER initiative and establish a lasting precedent for CER in our field. In this article, we aim to (a) define CER, with a focus on its application to radiology; (b) describe research activities that fall under the CER umbrella; (c) present CER topics in radiology that will receive priority for funding; (d) describe the current role of cost-effectiveness analysis in CER; and (e) encourage changes within our field that will support CER. Defining CER from the Radiologist’s Standpoint The American Reinvestment and Recovery Act established the Federal Coordinating Council for Comparative Effectiveness Research to direct the vision and priorities for CER conducted under all radiology.rsna.org ▪ Radiology: Volume 253: Number 3—December 2009 OPINION: Comparative Effectiveness Research federal agencies. On June 30, 2009, this council submitted a publicly available document to the President and Congress in which they defined CER and outlined their mission for the upcoming years (7). CER was defined as: ... the conduct and synthesis of research comparing the benefits and harms of different interventions and strategies to prevent, diagnose, treat and monitor health conditions in “real world” settings. The purpose of this research is to improve health outcomes by developing and disseminating evidence-based information to patients, clinicians, and other decisionmakers, responding to their expressed needs, about which interventions are most effective for which patients under specific circumstances. (7) The central goal of CER is to fill gaps in knowledge that add uncertainty to everyday medical decision making (6,7,11). One may ask, “Isn’t that the goal of most clinical research?” The primary difference is that the knowledge gained from CER should, in a transparent way, inform and improve health care decisions when multiple treatment options are available (6,7,11). A key component of CER is the identification and comparison of all relevant alternatives; in many settings, this precludes comparison with a placebo group or with a group that did not undergo treatment. Although CER has not been a central focus of imaging research to date, over the past 2 decades, CER activities have represented a growing minority of research initiatives in radiology (13–16). In this article, we will provide examples of published CER investigations in radiology and describe their potential roles in patient and policy decisions. A Patient’s Decision: Breast Cancer Screening in a BRCA1 Mutation Carrier Consider a BRCA1 mutation carrier who must decide how to manage her increased risk for breast cancer. If she opts for screening with imaging, she would like to know the relative benefits of mammography alone versus mammography combined with magnetic resonance (MR) imaging. MR imaging strategies are more sensitive but less specific in the detection Pandharipande and Gazelle of breast cancer than are mammographic strategies (17). However, sensitivity and specificity, in isolation, provide insufficient information concerning the longterm implications of choosing one strategy over another. Investigators have used computer modeling techniques to simulate the natural history of breast cancer in high-risk patients and then compared MR imaging and mammographic screening strategies in hypothetical high-risk populations (17,18). In so doing, they have estimated the life expectancy benefits of combined MR imaging and mammography over mammography alone (17,18). These studies show one application of CER in radiology and its potential value in a realworld setting. A Policymaker’s Decision: Funding CT Screening Programs for Smokers Consider a policymaker who is deciding whether to fund chest computed tomographic (CT) screening for smokers. By screening smokers with chest CT, it is possible to more than double the number of early-stage lung cancers detected (19– 24). Furthermore, one group of investigators reported a 10-year survival rate of more than 80% for patients with screendetected lung cancers in a single-arm study; this would represent a large potential improvement over the expected survival of patients with symptom-detected cancer (19). Nevertheless, these data are insufficient to enable the policymaker to make an informed decision. Biases such as lead time, length, and overdiagnosis could account for the reported positive results of single-arm screening studies and negate any predicted benefits of screening. Large randomized controlled trials performed to assess the benefit of CT screening in smokers are underway (25,26). In the interim, computer modeling techniques have been used to simulate comparative trials and quantify the mortality reduction, if any, that screening may confer (27–29). In these studies, investigators have estimated and accounted for the previously mentioned biases and have incorporated additional factors, such as the competing mortality risks in smokers and the sequelae of false-positive Radiology: Volume 253: Number 3—December 2009 ▪ radiology.rsna.org CT results (27–29). Mortality reductions conferred by screening were found to be modest or nonexistent (27–29). Until randomized controlled trial results become available, a policymaker could use results from CER modeling studies to estimate whether the predicted benefits of a CT screening program justify its cost or whether available resources might be better spent on a different public health program. It is important to note that computer modeling techniques are one way of conducting CER, but they are by no means the only way to conduct CER. In imaging research, when clinical trials are impossible or impractical to conduct, computer models can serve as powerful tools with which to predict the effects of imaging performance on long-term patient outcomes (5). Increasingly sophisticated modeling and model calibration techniques have resulted in models for a number of diseases that are highly accurate and useful (30). However, computer models are limited in that they cannot reproduce every facet of a complex disease process; therefore, they should be viewed as complementary to other research approaches. A variety of methods can and should be used for successful CER, as will be detailed later in this article, and the investigator’s research design should be based on the clinical question at hand. Research Activities under the CER Umbrella When surveying the literature on CER, it becomes apparent that there is no precise definition of what qualifies as CER and what does not (6,7,11,12). In fact, CER includes many types of investigations. Consider a scenario in which investigators conduct decision analysis with a variety of data sources, including meta-analysis, published randomized controlled trials, and observational data. Suppose the decision analysis informed a change in health care policy. To implement this change, the investigators develop a search engine with which to identify patients in their hospital’s database that could most benefit from the new policy. All elements of this 601 OPINION: Comparative Effectiveness Research process— data gathering and synthesis, medical decision making, and translation of results into practice—are integral to CER. While the endpoint of CER is to direct medical decisions, the heterogeneity of approaches that can be used to achieve this goal is well-recognized in the council’s document (7). Thus, instead of investing in a single type of research activity, the council’s intent is to promote the development of CER infrastructure. Accordingly, to guide investment priorities, the council put forth a strategic framework that included the following four core categories of activity that are essential to durable successful CER: research, human and scientific capital, CER data infrastructure, and dissemination and translation of CER (7). The council stated that CER may encompass more than one of these categories when addressing a broader agenda and specifically put forth three cross-cutting themes— priority populations, conditions, and interventions—to encourage a multipronged approach to their study (7). The core CER activities and crosscutting themes comprise the council’s strategic framework (7). Here, we focus on defining the core categories of CER activity. Research re- Pandharipande and Gazelle fers to hypothesis-driven patient-oriented investigations, such as studies in which researchers compare different imaging strategies. Human and scientific capital refers to educating investigators, particularly new investigators, in CER methods and to promoting innovations in CER methods. CER data infrastructure refers to the development of electronic databases that can facilitate CER. In radiology, such databases ideally should integrate patient and imaging information. Dissemination and translation of CER refers to creating decision aids, tools, and programs to effectively implement and disseminate CER results (7). Of these four categories, the council’s primary priority is the development of CER data infrastructure, underscoring their research engine approach (7). Given that radiology is a field that has been digital for 10 years or more in many academic institutions, our field has an opportunity for leadership in this domain, as will be discussed later in this article. High-Priority Areas of CER in Radiology As part of the American Reinvestment and Recovery Act, the Institute of Medicine was asked to develop a list of 100 top-priority areas for CER (3,6). The Institute of Medicine also issued its report on these topics on June 30, 2009, by quartile ranking (6). Of the 100 topics, nine were directly relevant to radiology (Table) (6). When reviewing these nine topics, two themes are striking. First, the Institute of Medicine identified oncologic radiology as the highest-priority area for CER initiatives in radiology (3,6). While only one imaging topic was included in the top 25, this topic—a call for investigators to compare the effectiveness of PET, CT, and MR imaging in all venues of cancer care— encompasses most of current cancer imaging (3,6). The Institute of Medicine’s emphasis in the second quartile on comparing screening strategies for breast and colorectal cancer and in the fourth quartile on studying outcomes after different treatment choices for liver metastases (including ablative therapies) further reflects the importance they placed on oncologic radiology (3,6). Second, the goal of two of the nine topics is to elucidate the role of specialists in imaging (6). In the third quartile, one topic calls for a comparison of the effectiveness of imaging CER Topics Relevant to Radiology Among 100 High-Priority Topics Designated by the Institute of Medicine Quartile First Second Second Second Third Third Fourth Fourth Fourth Objective Compare the effectiveness of imaging technologies in diagnosing, staging, and monitoring patients with cancer, including PET, MR imaging, and CT Compare the effectiveness of film-screen or digital mammography alone and mammography plus MR imaging in community practice–based screening for breast cancer in high-risk women of different ages, risk factors, and race or ethnicity Compare the effectiveness of new screening technologies (such as fecal immunochemical tests and CT colonography) and usual care (fecal occult blood tests and colonoscopy) in preventing colorectal cancer Compare the effectiveness and outcomes of care with obstetric US studies and care without use of US in normal pregnancies Compare the effectiveness of traditional risk stratification for coronary heart disease and noninvasive imaging (using coronary artery calcium, carotid intima media thickness, and other approaches) on coronary heart disease outcomes Compare the effectiveness of traditional and newer imaging modalities (eg, routine imaging, MR imaging, CT, and PET) when ordered for neurological and orthopedic indications by primary care practitioners, emergency department physicians, and specialists Compare the effectiveness of CT angiography and conventional angiography in assessing coronary stenosis in patients at moderate pretest risk of coronary artery disease Compare the effectiveness of diagnostic imaging performed by radiologists and nonradiologists Compare the effectiveness of surgical resection, observation, or ablative techniques on disease-free and overall survival, tumor recurrence, quality of life, and toxicity in patients with liver metastases Source.—Reference 6. Note.—Quartiles are arranged from top (first) to bottom (fourth). Topics relevant to radiology were extracted from 100 CER topics prioritized across all medical disciplines by the Institute of Medicine. Topics within each quartile (groups of 25) were considered of equivalent priority. PET ⫽ positron emission tomography, US ⫽ ultrasonography. 602 radiology.rsna.org ▪ Radiology: Volume 253: Number 3—December 2009 OPINION: Comparative Effectiveness Research studies ordered by specialists versus those ordered by nonspecialists (6). In the fourth quartile, another topic calls for a comparison of the effectiveness of imaging performed by radiologists versus that performed by nonradiologists (6). Inclusion of these topics may reflect concern about financially motivated self-referral or skepticism regarding the value of specialization for those performing imaging interpretations. Is Cost-effectiveness Analysis a Part of CER? The question of whether economic analysis should be included in or excluded from CER has been the subject of recent ardent debates (5,7,10,11,31–33). The council discusses stakeholders’ opposing opinions in their document (7). Proponents of including cost-effectiveness analysis argue that without it, the relative value of competing health care strategies will remain unknown (4,7,11,33). Thus, policy decisions regarding health care resource allocation will be uninformed and, likely, inappropriate. The proponents highlight the risk of passing up high-value care—which will improve our society’s overall life expectancy and quality of life at a reasonable cost—for expensive low-yield care (11). They argue that by excluding economic analysis, a critical aspect of prudent decision-making will be missing. The Society of Medical Decision Making, in their background paper on CER, invoked Garber’s well-known analogy of choosing healthcare programs at a societal level to selecting items from a restaurant menu (11,33). Regarding the importance of costeffectiveness analysis in CER, they stated that “it strengthens the usefulness of CER immensely . . . otherwise, it would be like translating the foreignlanguage menu of healthcare choices into your own language, but then putting ‘white-out’ over the prices” (11,33). Stakeholders who propose to exclude cost-effectiveness analysis from Pandharipande and Gazelle CER are concerned that cost information may inappropriately influence research efforts and medical decision making (4,7). Some argue that cost information will “taint” CER, rendering simultaneous analyses of clinical effectiveness more questionable (10). Many argue that the results of economic analyses would indirectly and inappropriately drive medical decisions by facilitating policies that would restrict coverage and access to care (4,7). Concerns have also been raised that economic analyses would unfavorably affect physician reimbursement (7). Perhaps as a result of these opposing viewpoints, the council does not emphatically include or exclude costeffectiveness analysis as part of CER (7). However, when detailing how a CER proposal should be judged, the council includes the potential effect of a proposal on costs as one factor that may be used to estimate its overall priority (7). Improving Care in Radiology through CER Initiatives To ensure that we, as radiologists, are able to provide high-quality high-value care for our patients, we will need to prioritize CER in the coming years. This will be best accomplished by focusing, in the immediate future, on developing a strong CER infrastructure, as the council emphasized in their proposed strategic framework (7). First, continued high-quality research efforts, ranging from studies in which researchers compare imaging test performance characteristics to those in which researchers compare longer-term outcomes for different imaging strategies, are critical for CER to succeed in radiology. Such efforts should invoke a highly interdisciplinary approach and include collaborations with clinical colleagues and experts in outcomes research methods. These collaborations are essential for durable CER initiatives. Several American College of Radiology Imaging Network (ACRIN) trials exemplify such research efforts. Multicenter ACRIN trials in which researchers evaluate new techniques for Radiology: Volume 253: Number 3—December 2009 ▪ radiology.rsna.org use in cancer detection and staging span the fields of breast (34–36), colorectal (37), cervical (38,39), prostate (40), and lung (25) cancer, and the results have been widely used to inform policy and reimbursement decisions. Second, investments in training for new investigators in outcomes research methods will be essential for CER in radiology to succeed. This will necessitate increased funding for career development awards. This will also require recruiting trainees into outcomes research careers, which will call on health services researchers in radiology to participate more actively in the training of residents and fellows. Third, electronic databases that facilitate CER will need to be further developed and maintained. The council’s emphasis on this aspect of CER infrastructure is an advantage for the radiology community (7). As noted earlier, many academic institutions are just a few steps away from being able to generate robust electronic databases that can integrate patient and imaging information. An example includes Render, a search application and repository developed at the institutional level that enables investigators to search a detailed database of patient and imaging information in an online format (41). This type of database will also facilitate the involvement of trainees in CER: It removes the burden of case identification, which enables trainees to focus more time on the core elements of a given research project. The National Oncologic PET Registry is an example of a national database (42). Its primary purpose is to provide evidence for PET-related Center for Medicare & Medicaid Services coverage decisions (42). Proposals for the development of a variety of electronic databases with which to conduct CER in radiology are likely to be prioritized in the near future. Fourth, development of tools and programs to disseminate CER results in radiology will need to receive greater emphasis. This is a challenge for CER in all fields. An example of this type of tool would be a Web-based algorithm in which a patient could enter demographic, health, and preference information to gain knowledge about the risks and ben603 OPINION: Comparative Effectiveness Research efits of using an imaging surveillance strategy in cancer detection. The development of high-quality decision support tools for patients and practitioners across imaging fields will undoubtedly improve the efficiency and quality of care in radiology. Conclusion There has been no better time than now for radiology, as a field, to make a lasting commitment to CER. New funding sources available to support outcomes research provide a singular opportunity to build the infrastructure that is needed to conduct high-quality CER. However, simultaneous support within the radiology community is also needed at multiple levels. Radiology departments within academic institutions will need to allocate greater resources to CER efforts, providing start-up and ongoing support to “dry laboratory” outcomes researchers that is commensurate to that provided for investigators in “wet laboratory” basic science settings. Radiologic societies will need to augment funds allocated to train new investigators in outcomes research methods and support innovative CER proposals. The private practice community can substantially contribute to CER by increasing contributions to radiologic societies to fund these endeavors. Demonstrable support within the radiology community, in turn, will increase the likelihood of sustained federal CER funding and ensure that future research endeavors in radiology will include both technology development and assessment, without disproportionate representation of the former. 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