Diagnostic Imaging Use for Patients With Cancer: Opportunities to Enhance Value

Geographic variation in Medicare spending has been extensively studied over the past 40 years, most notably by researchers at the Dartmouth Institute for Health Policy and Clinical Practice. Medicare spending varies substantially across hospital referral regions (HRRs), even after differences in patient case mix are adjusted for, and additional spending does not appear to improve health outcomes for beneficiaries, nor is it associated with higher care quality.^1,2 These data collectively have led many to conclude that there is wasteful health care spending within Medicare that could be reduced through policy interventions aimed at reducing excessive practice variation in high-spending geographic areas.

The Choosing Wisely campaign sponsored by the American Board of Internal Medicine Foundation and Consumer Reports encourages clinicians, patients, and other health care stakeholders to more carefully consider the value of recommended care with the goal of reducing overuse of low-value care. Low-value imaging tests that are unlikely to affect clinical decisions are a prime target of the campaign. The article by Makarov et al³ in this issue of JAMA Oncology highlights 2 relevant examples by examining patterns of care associated with the use of staging imaging in a cohort of patients diagnosed with favorable-prognosis cancers of the breast and prostate. Consistent with prior studies, the authors demonstrate substantial overuse of imaging in these 2 patient populations. Overall, approximately 40% of patients underwent imaging tests (eg, computed tomography scans, bone scans, or positron emission tomography–computed tomography scans) during the initial period following their cancer diagnosis. Such tests are unlikely to demonstrate any evidence of metastatic spread, and they subject the patients to risk of harm due to radiation exposure and false positive results that prompt additional invasive testing. The financial costs of unnecessary imaging in this patient population are substantial, and so eliminating it represents an opportunity for significant cost savings while maintaining cancer care quality.

The article by Makarov et al³ adds to a large body of literature demonstrating significant associations between geography and variations in health care utilization. Most notably, the study extends current understanding by demonstrating that regions with high imaging rates for favorable-risk breast cancer were significantly likely to also have high imaging rates of for favorable-risk prostate cancer, and, to a lesser extent, vice versa. These observed regional-level associations across disease regions provide further evidence to suggest that factors within an HRR drive variations in health care utilization regardless of clinical context.

However, it is important to distinguish the authors’ findings indicating inappropriate use of low-value care from the related but distinct issue of excess geographic variation in health care utilization. Although the existence of excess variation in health care spending without improvement in patient outcomes suggests that inappropriate utilization may be a primary explanatory factor, prior studies have indicated that only a small proportion of observed geographic variation in health care spending can be explained by inappropriate use.^4,5 Furthermore, as alluded to in the study by Makarov et al,³ high-spending regions tend to have higher rates of both appropriate and inappropriate care, while lower-spending regions have lower rates of both appropriate and inappropriate care. This has been referred to as the thermostat model.⁶ If correct, it might suggest that policy interventions targeted at the regional level must be designed with extreme care, lest they reduce utilization of appropriate care for patients who need it along with intended reductions in inappropriate care.

The 2013 Institute of Medicine (IOM) panel,⁷ cited by Makarov et al,³ came to a similar conclusion when considering the question of whether Medicare should adopt a geographically targeted value index to base clinicians’ payments on the performance of their geographic area. The panel’s findings confirmed the presence of substantial geographic variation in health care spending at the HRR level, but the panel also found that variation in expenditures was present at every level of geography, including among physicians within the same group. Therefore, the IOM panel recommended against adoption of a geographically targeted value index because geographic units are not where most health care decisions are made, and such payment reform would unfairly punish high-value clinicians in low-value regions and reward low-value clinicians in high-value regions.

As noted by Roman and Asch,⁸ “deadopting” low-value care is a slow and difficult process.⁸ National consensus guidelines over at least the past decade have recommended against routine use of staging imaging for patients diagnosed with early-stage, favorable-risk prostate cancer and breast cancer. Nevertheless, a substantial proportion of clinicians continue to order the tests despite abundant evidence suggesting that the tests are of little value. The study by Makarov et al³ suggests that overuse of low-value imaging tests among cancer patients may be driven by factors within geographic regions. However, despite extensive study, we still do not fully understand what these factors are and how they contribute to overuse of inappropriate care. Potential factors may include local market forces such as regional oversupply of health resources and resultant competitive stress for health systems and clinicians in such regions. They may include differences in local culture and norms of care among clinicians regarding what is considered the standard of care, particularly for discretionary medical decisions. Clinicians’ judgment may be colored by a tendency to seek information that confirms what they already believe (confirmation bias) or a desire to avoid missing a rare case of metastatic disease (loss averision).⁸ Regional variation is likely driven by a complex interplay of factors that exist at the regional, health system, and clinician level.

As our understanding of explanatory factors driving regional patterns of health care continues to evolve, interventions designed to educate, enhance awareness, and support shared medical decision making between patients and physicians are most appropriate. The Choosing Wisely campaign is a laudable example, and it will be critical for continued research to examine temporal trends in patterns of care following its implementation to assess the potential effects. Payment policies that reward high-value care and discourage low-value care are also promising. However, as concluded by the recent IOM report, smaller-level variation exists within individual HRRs, and so payment policies applied uniformly across geographic regions may be unjust and risk adversely affecting patient outcomes by reducing overall care utilization regardless of appropriateness.

Corresponding Author: Samuel Swisher-McClure, MD, MSHP, Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Blvd, TRC 2 W, Philadelphia, PA 19104 (Swisher-McClure@uphs.upenn.edu).

Published Online: March 12, 2015. doi:10.1001/jamaoncol.2015.31.

Conflict of Interest Disclosures: None reported.