Grant Number:	5R01CA190017-04 Interpret this number
Primary Investigator:	Gross, Cary
Organization:	Yale University
Project Title:	Impact of Social Contagion on Physician Use of Unproven Cancer Interventions
Fiscal Year:	2017

DESCRIPTION (provided by applicant): Efforts to align cancer care with the best available medical evidence have largely focused on disseminating guidelines, enhancing physician-patient communication, and revising payment schema. Although these are critical strategies, it is possible that another major influence on physician behavior has been overlooked - what if the practice of a physician's peers was a major determinant of whether she or he adopts one new cancer intervention or abandons another? We propose a novel investigation of the impact of physicians and physician patient-sharing networks on the adoption and abandonment of cancer interventions. Physician networks are groups of physicians who work with one another either directly or indirectly, through shared patients. New cancer management approaches could diffuse through such networks via social contagion, whereby ideas and behaviors spread through interconnected groups of people. It is particularly timely to explore new constructs that shape the delivery of cancer care, as the rapid diffusion of expensive, unproven, and sometimes ineffective cancer interventions poses a significant threat to the sustainability of the cancer car system and to the health of individual patients. For instance, the use of advanced imaging tests (AITs) such as PET scans and MRI for women with breast cancer has increased substantially over the past decade, despite little evidence supporting their use. Further, once an intervention has diffused into practice and become a standard of care, it can remain widely used even when there is evidence that it provides limited or no incremental benefit compared to less expensive or burdensome alternatives. For example, radiation oncologists have been reluctant to abandon the lengthier and more expensive "standard" courses of radiation for breast cancer, despite evidence that shorter courses yield similar outcomes. To address these concerns, we will focus on Medicare beneficiaries undergoing breast cancer care. We aim to (1) construct physician patient-sharing networks; (2) assess the impact of physicians and social contagion on the early adoption of AITs and the early abandonment of more costly and inconvenient longer-course radiotherapy; (3) identify physician and physician network characteristics associated with early adoption or abandonment of interventions; and (4) assess the population-level impact of physicians' adoption and abandonment of these interventions in terms of costs, care patterns, and outcomes, across physicians. Within any complex system, it is critical to understand factors that drive the behavior of individuals. A rigorous analysis of the complex web of physician and patient interactions in cancer care can not only provide a rich understanding of how physicians influence the behavior of their peers, but also identify a potentially powerful lever for inducing physicians to abandon ineffective interventions or discourage the use of unproven ones (Provocative Question E-3).




Physician trajectories of abandoning long-course breast radiotherapy and their cost impact.
Authors: Xu X. , Soulos P.R. , Herrin J. , Wang S.Y. , Pollack C.E. , Evans S.B. , Yu J.B. , Gross C.P. .
Source: Health services research, 2021 Jun; 56(3), p. 497-506.
EPub date: 2020-10-18.
PMID: 33070305
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Income disparities in needle biopsy patients prior to breast cancer surgery across physician peer groups.
Authors: Killelea B.K. , Herrin J. , Soulos P.R. , Pollack C.E. , Forman H.P. , Yu J. , Xu X. , Tannenbaum S. , Wang S.Y. , Gross C.P. .
Source: Breast cancer (Tokyo, Japan), 2020 May; 27(3), p. 381-388.
EPub date: 2019-12-02.
PMID: 31792804
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Peer Influence on Physician Use of Shorter Course External Beam Radiation Therapy for Patients with Breast Cancer.
Authors: Yu J.B. , Pollack C.E. , Herrin J. , Soulos P.R. , Zhu W. , Xu X. , Gross C.P. .
Source: Practical radiation oncology, 2020 Mar-Apr; 10(2), p. 75-83.
EPub date: 2019-11-27.
PMID: 31785370
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Persistent Use of Extended Fractionation Palliative Radiotherapy for Medicare Beneficiaries With Metastatic Breast Cancer, 2011 to 2014.
Authors: Yu J.B. , Pollack C.E. , Herrin J. , Zhu W. , Soulos P.R. , Xu X. , Gross C.P. .
Source: American journal of clinical oncology, 2019 Jun; 42(6), p. 493-499.
PMID: 31033511
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Association Between Degrees of Separation in Physician Networks and Surgeons' Use of Perioperative Breast Magnetic Resonance Imaging.
Authors: Shi Y. , Pollack C.E. , Soulos P.R. , Herrin J. , Christakis N.A. , Xu X. , Gross C.P. .
Source: Medical care, 2019 Jun; 57(6), p. 460-467.
PMID: 31008899
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An empiric approach to identifying physician peer groups from claims data: An example from breast cancer care.
Authors: Herrin J. , Soulos P.R. , Xu X. , Gross C.P. , Pollack C.E. .
Source: Health services research, 2019 Feb; 54(1), p. 44-51.
EPub date: 2018-11-28.
PMID: 30488484
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Surgeon peer network characteristics and adoption of new imaging techniques in breast cancer: A study of perioperative MRI.
Authors: Tannenbaum S.S. , Soulos P.R. , Herrin J. , Pollack C.E. , Xu X. , Christakis N.A. , Forman H.P. , Yu J.B. , Killelea B.K. , Wang S.Y. , et al. .
Source: Cancer medicine, 2018 Dec; 7(12), p. 5901-5909.
EPub date: 2018-11-15.
PMID: 30444005
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Physician peer group characteristics and timeliness of breast cancer surgery.
Authors: Bachand J. , Soulos P.R. , Herrin J. , Pollack C.E. , Xu X. , Ma X. , Gross C.P. .
Source: Breast cancer research and treatment, 2018 Aug; 170(3), p. 657-665.
EPub date: 2018-04-24.
PMID: 29693229
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The Impact of Social Contagion on Physician Adoption of Advanced Imaging Tests in Breast Cancer.
Authors: Pollack C.E. , Soulos P.R. , Herrin J. , Xu X. , Christakis N.A. , Forman H.P. , Yu J.B. , Killelea B.K. , Wang S.Y. , Gross C.P. .
Source: Journal of the National Cancer Institute, 2017-08-01; 109(8), .
PMID: 28376191
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