2019

Modeling peer effect modification by network strength: The diffusion of implantable cardioverter defibrillators in the US hospital network

Statistics in Medicine

A. James O'Malley, Erika L. Moen, Julie P. W. Bynum, Andrea M. Austin, Jonathan S. Skinner

We develop methodology that allows peer effects (also referred to as social influ- ence and contagion) to be modified by the structural importance of the focal actor's position in the network. The methodology is first developed for a sin- gle peer effect and then extended to simultaneously model multiple peer-effects and their modifications by the structural importance of the focal actor. This work is motivated by the diffusion of implantable cardioverter defibrillators (ICDs) in patients with congestive heart failure across a cardiovascular dis- ease patient-sharing network of United States hospitals. We apply the general methodology to estimate peer effects for the adoption of capability to implant ICDs, the number of ICD implants performed by hospitals that are capable, and the number of patients referred to other hospitals by noncapable hospi- tals. Applying our novel methodology to study ICD diffusion across hospitals, we find evidence that exposure to ICD-capable peer hospitals is strongly asso- ciated with the chance a hospital becomes ICD-capable and that the direction and magnitude of the association is extensively modified by the strength of that hospital's position in the network, even after controlling for effects of geography. Therefore, interhospital networks, rather than geography per se, may explain key patterns of regional variations in healthcare utilization.

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Association of Receiving Multiple, Concurrent Fracture-Associated Drugs With Hip Fracture Risk

JAMA Network

Rebecca T. Emeny, PhD, MPH; Chiang-Hua Chang, PhD; Jonathan Skinner, PhD; A. James O’Malley, PhD; Jeremy Smith, MPH; Gouri Chakraborti, MA; Clifford J. Rosen, MD; Nancy E. Morden, MD, MPH

Manyprescriptiondrugsincreasefracturerisk,whichraisesconcernforpatients receiving 2 or more such drugs concurrently. Logic suggests that risk will increase with each additional drug, but the risk of taking multiple fracture-associated drugs (FADs) is unknown.

ToestimatehipfractureriskassociatedwithconcurrentexposuretomultipleFADs.

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Use of Advance Care Planning Billing Codes for Hospitalized Older Adults at High Risk of Dying: A National Observational Study

Journal of Hospital Medicine

Amber E Barnato, MD, MPH, MS; A James O’Malley, PhD; Jonathan S Skinner, PhD; John D Birkmeyer, MD

Advance care planning (ACP) is the process where- in patients, in discussions with their healthcare providers, family members, and other loved ones, make individual decisions about their fu- ture healthcare or prepare proxies to guide future medical treatment decisions.1,2 In 2016, the Centers for Medicare and Medicaid Services (CMS) began paying providers for ACP by using billing codes 99497 (first 30 min of ACP) and 99498 (additional 30 min of ACP). According to the CMS, during the first year after the billing codes were introduced, 22,864 providers billed for ACP conversations with 574,621 patients.3 While all adults are eligible, common triggers for ACP in- clude advanced age, serious illness, and functional status changes that confer an increased risk of dying. We explored the early uptake of the ACP billing code in a large national physician practice that provided mandatory education in use of the ACP billing code, offered a small financial incentive for ACP documentation, and primed physicians to reflect on the patient’s risk of dying in the next year at the time of hospital admission.

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Measuring racial segregation in health system networks using the dissimilarity index

Social Science & Medicine
Austin AM, Carmichael DQ, Bynum JPW, Skinner JS.

Racial disparities in the end-of-life treatment of patients are a well observed fact of the U.S. healthcare system. Less is known about how the physicians treating patients at the end-of-life influence the care received. Social networks have been widely used to study interactions with the healthcare system using physician patient-sharing networks. In this paper, we propose an extension of the dissimilarity index (DI), classically used to study geographic racial segregation, to study differences in patient care patterns in the healthcare system. Using the proposed measure, we quantify the unevenness of referrals (sharing) by physicians in a given region by their patients' race and how this relates to the treatments they receive at the end-of-life in a cohort of Medicare fee-for-service patients with Alzheimer's disease and related dementias. We apply the measure nationwide to physician patient-sharing networks, and in a sub-study comparing four regions with similar racial distribution, Washington, DC, Greenville, NC, Columbus, GA, and Meridian, MS. We show that among regions with similar racial distribution, a large dissimilarity index in a region (Washington, DC DI = 0.86 vs. Meridian, MS DI = 0.55), which corresponds to more distinct referral networks for black and white patients by the same physician, is correlated with black patients with Alzheimer's disease and related dementias receiving more aggressive care at the end-of-life (including ICU and ventilator use), and less aggressive quality care (early hospice care).

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Chronic Condition Measurement Requires Engagement, Not Measurement Alone.

The Journal of Ambulatory Care Management
Austin AM1, Carmichael D, Berry S, Gozansky WS, Nelson EC, Skinner JS, Barr PJ.

Patient-reported outcome measures (PROMs) have great promise, but evidence of success is mixed. This study uses data from Dartmouth-Hitchcock Medical Center and Kaiser-Permanente Colorado to evaluate providing PROMs directly to the primary care physician. We compared changes over time in urinary incontinence, falls, and mental and physical health between clinics providing augmented PROMs (N = 202 patients) and control clinics (N = 102 patients). Both the control and treatment groups exhibited improvements, but there was no significant difference in outcomes over time. These results suggest that measuring and printing out PROMs for primary care physicians will not result in better patient outcomes without physician clinical engagement.

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Association of Receiving Multiple, Concurrent Fracture-Associated Drugs With Hip Fracture Risk

JAMA Network

Rebecca T. Emeny, PhD, MPH; Chiang-Hua Chang, PhD; Jonathan Skinner, PhD; A. James O’Malley, PhD; Jeremy Smith, MPH; Gouri Chakraborti, MA;Clifford J. Rosen, MD; Nancy E. Morden, MD, MPH

Choosing between competing treatment options is difficult for patients and clinicians when results from randomized and observational studies are discordant. Observational real-world studies yield more generalizable evidence for decision making than randomized clinical trials, but unmeasured confounding, especially in time-to-event analyses, can limit validity.

The association between medical care utilization and health outcomes: A spatial analysis

Regional Science & Urban Economics
Francesco Moscone, Jonathan Skinner, Elisa Tosetti, Laura Yasaitis

As health care spending continues to strain government and household budgets, there is increasing interest in measuring whether the incremental dollar spent on health care is worth it. In studying this question, researchers often make two key assumptions: that health care intensity can be summarized by a single index such as average spending, and that samples of hospitals or regions are spatially independent: Manhattan and the Bronx are no more alike than are Manhattan and San Diego, for example. In this paper we relax both assumptions. Using detailed data on 897,008 elderly Medicare enrolees with acute myocardial infarction (or a heart attack) during 2007–11, we find first that the total level of health care spending has little impact on health outcomes; more important is how the money is spent. …

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Physician Beliefs and Patient Preferences: A New Look at Regional Variation in Health Care Spending

American Economic Journal
David Cutler, Jonathan S. Skinner, Ariel Dora Stern, and David Wennberg*

There is considerable controversy about the causes of regional variations in health care expenditures. Using vignettes from patient and physician surveys linked to fee-for-service Medicare expenditures, this study asks whether patient demand-side factors or physician supply-side factors explain these variations. The results indicate that patient demand is relatively unimportant in explaining variations. Physician organizational factors matter, but the most important factor is physician beliefs about treatment. In Medicare, we estimate that 35 percent of spending for end-of-life care and 12 percent of spending for heart attack patients (and for all enrollees) is associated with physician beliefs unsupported by clinical evidence. (JEL D83, H75, I11, I18)

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