Author + information
- Received August 18, 2016
- Revision received October 26, 2016
- Accepted October 26, 2016
- Published online January 30, 2017.
- Khadijah Breathett, MDa,∗ (, )
- Larry A. Allen, MD, MHSa,
- Laura Helmkamp, MSb,
- Kathryn Colborn, PhDb,
- Stacie L. Daugherty, MD, MSPHa,
- Prateeti Khazanie, MD, MPHa,
- Richard Lindrooth, PhDc and
- Pamela N. Peterson, MD, MSPHa,d
- aUniversity of Colorado, Anschutz Medical Campus, Division of Cardiology, Aurora, Colorado
- bUniversity of Colorado Adult and Child Consortium for Health Outcomes Research and Delivery Science, Aurora, Colorado
- cUniversity of Colorado, Department of Health Systems, Management and Policy in the Colorado School of Public Health, Aurora, Colorado
- dDenver Health Medical Center, Denver, Colorado
- ↵∗Reprint requests and correspondence:
Dr. Khadijah Breathett, University of Colorado, Anschutz Medical Campus, RC2, Mail Stop B139, 12700 East 19th Avenue, Room 8103, Aurora, Colorado 80045.
Objectives The aim of this study was to determine if the Affordable Care Act (ACA) Medicaid Expansion was associated with increased census-adjusted heart transplant listing rates for racial/ethnic minorities.
Background Underinsurance limits access to transplants, especially among racial/ethnic minorities. Changes in racial/ethnic listing rates post-ACA Medicaid Expansion are unknown.
Methods Using the Scientific Registry of Transplant Recipients, we analyzed 5,651 patients from early adopter states (implemented the ACA Medicaid Expansion by January 2014) and 4,769 patients from non-adopter states (no implementation during the study period) from 2012 to 2015. Piecewise linear models, stratified according to race/ethnicity, were fit to monthly census-adjusted rates of heart transplant listings before and after January 2014.
Results A significant 30% increase in the rate of heart transplant listings for African-American patients in early adopter states occurred immediately after the ACA Medicaid Expansion on January 1, 2014 (before 0.15 to after 0.20/100,000; increase 0.05/100,000; 95% confidence interval [CI]: 0.01 to 0.08); in contrast, the rates for African-American patients in non-adopter states remained constant (before and after 0.15/100,000; increase 0.006/100,000; 95% CI: –0.03 to 0.04). Hispanic patients experienced an opposite trend, with no significant change in early adopter states (before 0.03 to after 0.04/100,000; increase 0.01/100,000; 95% CI: –0.004 to 0.02) and a significant increase in non-adopter states (before 0.03 to after 0.05/100,000; increase 0.02/100,000; 95% CI: 0.002 to 0.03). There were no significant changes in listing rates among Caucasian patients in either early adopter states or non-adopter states.
Conclusions Implementation of the ACA Medicaid Expansion was associated with increased heart transplant listings in African-American patients but not in Hispanic or Caucasian patients. Broadening of the ACA in states with large African-American populations may reduce disparities in heart transplant listings.
Racial/ethnic minorities are not listed for heart transplantation at equitable levels of disease prevalence (1–4). Underinsurance is a major contributor to this inequality in heart transplant allocation among racial/ethnic minorities (1–6). Adequate health insurance or demonstration of ability to pay is a requirement for heart transplantation listing in all programs (5). Approximately 43% of heart transplant patients have public insurance, and 30% of those patients have Medicaid (7). Historically, racial/ethnic minorities have had the highest rates of uninsurance (8). With the implementation of the Affordable Care Act (ACA), many racial/ethnic minorities have improved access to health care (9–11). However, the correlation of ACA Medicaid Expansion with heart transplant listing rates among racial/ethnic minorities is unknown.
Medicaid expansion did not occur uniformly, with only 44% of states expanding Medicaid (early ACA adopter states) in 2014 (12). Given the increased number of racial/ethnic minorities insured under the ACA Medicaid Expansion, we hypothesized that the census-adjusted heart transplant listing rates for racial/ethnic minorities would increase in early adopter ACA Medicaid Expansion states compared with non-adopter states.
Patients listed for heart transplant were identified in the national Scientific Registry of Transplant Recipients (SRTR) database. The SRTR data system includes data on all donor, wait-listed candidates, and transplant recipients in the United States, submitted by the members of the Organ Procurement and Transplantation Network. The SRTR database collects data on demographic characteristics, including race/ethnicity, comorbidities, clinical data, insurance, education level, and transplant center state; details have been reported elsewhere (13). SRTR reports <1% of race/ethnicity data as missing over the past decade (14). The Health Resources and Services Administration, U.S. Department of Health and Human Services, provides oversight to the activities of the Organ Procurement and Transplantation Network and SRTR contractors, and sites are periodically audited.
Adults ≥18 years of age with a single listing for heart transplant in the United States between January 2012 and December 2015 were identified. Patients with a listed race of African American or Caucasian or an ethnicity of Hispanic were included.
ACA medicaid expansion state stratification
Early adopter states were defined as those that implemented ACA Medicaid Expansion by January 2014, and non-adopter states were defined as those that did not implement by December 2015 (Figure 1). Patients were aggregated into early adopter and nonadopter state groups. Patients who were listed in states that adopted the ACA Medicaid Expansion between February 2014 and December 2015 (n= 5) or states that reduced coverage with adoption were excluded (n = 2) (12); this approach was taken because the objective of the study was to compare access to heart transplant listing before and after implementation of the ACA Medicaid Expansion in January 2014.
Medicaid was partially expanded before the federal ACA Medicaid Expansion of 2014 in 19 states and Washington, DC (Figure 1) (15). However, these partial expansions were limited in size and scope and had substantially lower enrollment than the ACA Medicaid Expansion (15). These states were therefore included in the analysis, and we did not control for the timing of the partial pre-ACA Medicaid Expansion.
The primary outcome of interest was the census-adjusted rate of heart transplant listing. The listing rate was chosen as the outcome rather than the heart transplantation rate because insurance is directly related to the initial step of heart transplant listing. After a patient is listed, insurance type has little association with likelihood of transplantation.
The state-level census data were obtained from the annual projected U.S. Census Bureau estimates and were used to calculate census-adjusted rates of heart transplant listing according to state, race, and ethnicity. Census data were not available for 2015; therefore, 2014 census data were used to adjust heart transplant listings from 2014 to 2015. All other census years were available for adjustment. The state-level census was chosen as the denominator because statewide data on the at-risk end-stage heart failure population who may be eligible for heart transplant are not available. In addition, the racial/ethnic populations differ significantly in early adopter and non-adopter states. The U.S. census has been used as the denominator in previous studies to illustrate transplantation rates (16).
Baseline patient characteristics were compared in ACA early adopter and non-adopter states by using chi-squared tests for categorical variables and Wilcoxon-Mann-Whitney tests for continuous variables.
Piecewise linear models were fit to monthly census-adjusted rates of heart transplant listings to test the impact of ACA Medicaid Expansion implementation. The piecewise linear models incorporate parameters for changes in heart transplant listings over time, and they permit the slopes to differ between early adopter and non-adopter states before and after the ACA Medicaid Expansion. This approach was chosen over a pre-test/post-test design because the data did not seem to satisfy the parallel trends assumption. Most importantly, piecewise linear models allow for estimation of an instantaneous change in rate, which we set at January 2014, concurrent with the ACA Medicaid Expansion. Piecewise models have been used to estimate the association between policy implementation and patient outcomes in previous studies (17,18). To implement this model, binary factors were specified for the ACA Medicaid Expansion (before and after January 2014) and for early adopter states versus non-adopter states. Models were stratified according to race/ethnicity. In a secondary analysis, models were specified for the most populated insurance groups (Medicaid, private, and Medicare), in a similar fashion.
Statistical analyses were performed by using SAS version 9.4 (SAS Institute, Inc., Cary, North Carolina) and R statistical software (R Foundation for Statistical Computing, Vienna, Austria).
Between 2012 and 2015, there were 5,651 patients listed in 23 early adopter states plus Washington, DC, and 4,769 listed in 20 non-adopter states (Table 1, Figure 1). The majority of patients listed for transplant were Caucasian in both the early adopter and non-adopter states (62.8% and 60.2%, respectively), followed by African-American patients (20.9% and 29.3%) and Hispanic patients (9.7% and 7.8%). Compared with 2012 census demographic characteristics, listing proportions were similar for Caucasian patients from both early adopter (62.8% listed, 60.1% census) and non-adopter (60.2% listed, 61.3% census) states. Among African-American patients, listing proportions were higher than census demographic characteristics in both early adopter (20.9% listed, 9.3% census) and non-adopter (29.3% listed 16.9% census) states. Among Hispanic patients, listing proportions were lower than census demographic characteristics in both early adopter (9.7% listed, 20.1% census) and non-adopter (7.8% listed, 16.5% census) states.
The proportion of patients listed for heart transplant according to insurance type included private insurance in 50.3% of early adopter states and 51.0% of non-adopter states, Medicaid in 15.8% of early adopter states and 8.2% of non-adopter states, and Medicare in 30.1% of early adopter states and 36.2% of non-adopter states. Approximately one-half of patients listed in non-adopter states were status 1B. Patients from early adopter states were split into thirds at status 1A, 1B, and 2. The patterns were similar among Caucasian patients for each state group (Online Table 1). However, among African-American and Hispanic patients from both state groups, a larger proportion were listed as status 1B and a smaller proportion were listed as status 2.
The census-adjusted heart transplant listing rates were highest in African-American patients throughout the study period, followed by Caucasian and Hispanic patients (Figure 2, Online Figure 1). Within each race/ethnicity, heart transplant listing rates were similar in early and nonadopter states before the ACA Medicaid Expansion (Table 2).
Immediately after the ACA Medicaid Expansion, the heart transplant listing rate increased significantly by 30% in African-American patients in early adopter states (before 0.15 to after 0.20/100,000; increase 0.05/100,000; 95% confidence interval [CI]: 0.01 to 0.08). Rates were constant among African-American patients in non-adopter states (before and after 0.15/100,000; increase 0.006/100,000; 95% CI: –0.03 to 0.04) (Figure 2, Table 2). Rates increased in Hispanic patients from both early adopter and nonadopter states, but the change was only significant in non-adopter states (early adopter—before 0.03 to after 0.04/100,000; increase 0.01/100,000; 95% CI: –0.004 to 0.02; non-adopter—before 0.03 to after 0.05/100,000; increase 0.02/100,000; 95% CI: 0.002 to 0.03). Rates did not change significantly among Caucasian patients from either early adopter or nonadopter states (early adopter—before 0.08 to after 0.09; increase 0.004/100,000; 95% CI: –0.01 to 0.02; non-adopter—before and after 0.08; increase 0.01/100,000; 95% CI: –0.001 to 0.03). Heart transplant listing rates stabilized after initial changes post-ACA Medicaid Expansion. From 2014 to 2015, the rate of change over time was similar within each race/ethnicity (Figure 2, Table 2, Online Table 2).
In a secondary analysis, we evaluated changes in racial/ethnic listing rates post-ACA Medicaid Expansion among each subgroup of insurance. Among those with Medicaid, African-American patients had somewhat higher heart transplant listing rates pre–ACA Medicaid Expansion in early adopter states compared with non-adopter states. When the ACA Medicaid Expansion was implemented, rates further diverged in African-American patients with Medicaid and were significantly higher in early adopter states from 2014 to 2015 (Figure 3A) (non-overlapping CIs). Among those with Medicaid, no change in listing rates was observed pre- and post- ACA in other racial groups. Among patients with private insurance and among those with Medicare, listing rates increased in African-American patients at the time of the ACA Medicaid Expansion in both early adopter and non-adopter states but with no significant differences in rates between the 2 groups. Among the other racial groups with private insurance and Medicare, no significant differences in listing rates were observed in either early adopter or non-adopter states after ACA Medicaid Expansion (Figures 3B and 3C) (overlapping CIs). In all insurance groups, rates were highest post–ACA Medicaid Expansion in African-American patients in early adopter states.
The ACA Medicaid Expansion was associated with a significant increase in heart transplant listings in African-American patients but not among Hispanic or Caucasian patients. These findings suggest that improved access to insurance may be a partial solution to reducing racial/ethnic disparities in organ allocation in the United States.
To our knowledge, this study is the first to evaluate the association between the ACA and racial/ethnic listings for heart transplant. This study is strengthened by using census-adjusted rates that account for racial/ethnic state-wide differences in population rather than comparing count data reflected in the proportions. Although listing rates for African-American patients are higher than for Caucasian and Hispanic patients, rates of heart transplant listings remain lower than anticipated for African-American patients. African-American patients are at highest risk for heart failure, have 2- to 3-fold higher prevalence of heart failure than Caucasian patients before 75 years of age, and have the highest rates of death from heart failure (19–21). The factors that contribute to this disparity are numerous, including referral patterns, comorbidities, social support, education, patient-centered decisions, and adherence (2,3,22–24). Because the evaluation and treatment course for heart transplantation are expensive, one of the greatest factors associated with disparities in heart transplantation is underinsurance and uninsurance (2,5,24). A recent research letter by Oliveira et al. (25) showed that the ACA Medicaid Expansion was associated with increased heart transplant listings in early adopter states versus non-adopter states. Our findings suggest that expanding insurance coverage may improve racial/ethnic equity in access to heart transplantation, a life-saving treatment.
Results of the present study add to a body of literature that suggests economic and racial/ethnic barriers to health care can be reduced with insurance (11,26,27). The ACA increased access to insurance for all citizens and especially African-American patients (8). All races/ethnicities had reductions in the proportion of uninsured populations after the ACA Medicaid Expansion, and the largest decline was seen in African-American subjects (28). In the National Health Interview Survey, the ACA was associated with significantly improved access to insurance, reduction in delay of care, and increased likelihood of pursuing necessary care among African-American and Hispanic patients (29). Similarly, state-based analyses of the ACA implementation have revealed reductions in racial/ethnic disparities for health care in Massachusetts, California, and Oregon, with the greatest gains in African-American subjects compared with other groups (30–32). These reductions in disparities were seen despite known higher comorbidities among African-American subjects (21).
Our finding that Hispanic patients from early adopter states did not have an increased probability of being listed for a heart transplant is consistent with other research showing that health care disparities have not been universally reduced under the ACA (11,33,34). There are various possible explanations for this finding. First, the risk of heart failure is higher in Hispanic patients than in Caucasian patients (19), but the risk of death from heart failure is lower (20). Therefore, the prevalence of end-stage heart failure may be lower than expected in this population. Second, longer follow-up may be needed to assess the full change in health care access associated with the ACA Medicaid Expansion, although the time trends available in our data suggest immediate changes rather than gradual ones. Third, the state of Texas accounted for most of the variability among nonadopter states, and Texas had a notable decrease in the proportion of uninsured, nonelderly Hispanic patients from 37% in 2012 to 32% in 2014 (35). This finding could be related to federally mandated, non-Medicaid Expansion changes in ACA policy and could account for the marginal increase in heart transplant listings among non-adopter states in 2014. However, no increase in listing rates among Hispanic patients with private insurance was observed in either state group. Finally, an important factor may be that undocumented individuals are ineligible for insurance coverage through the ACA (33,34,36,37). The 3 states with the most undocumented individuals include California (6%), which accounts for most of the variability of results of early adopter states, and 2 non-adopter states, Texas (6%) and Florida (4%) (38). More than 70% of undocumented individuals from California and Texas are Mexican, and 19% from Florida are Mexican. Given these factors, it should not be surprising that health policy changes for heart failure care do not manifest the same across racial/ethnic groups.
Because the number of donor hearts is limited, it is critical that different racial and ethnic groups have equitable access to this scarce resource (39). The heart transplant matching process is changing to increase allocation of suitable organs to patients who are deemed to have the greatest need. This change could be beneficial to racial/ethnic minorities who were more likely to be listed if an inotrope was indicated in their care (40). However, guidelines for transplantation are not concrete. Conservative transplantation programs may place greater weight on insurance type when deciding which candidates should be listed for transplantation. In some states, patients with basic health care coverage such as Medicaid may not be given equitable candidacy as patients with Medicare plus private insurance because Medicaid programs will not universally cover costs of transplantation (41). It is paramount to avoid increasing racial/ethnic disparities because the selection process is calibrated particularly among politically divided organ procurement organizations. The main alternative to transplant (i.e., left ventricular assist devices) is also disproportionately allocated at lower rates to racial/ethnic minorities (42,43). Thus, further study of the impact of the ACA Medicaid Expansion on access to all advanced heart failure therapies would provide necessary additional context for understanding racial/ethnic disparities in this disease.
Alternate explanations for the increase in heart transplant listings among African-American subjects from early adopter states should be considered. First, in addition to implementation of the ACA Medicaid Expansion on January 1, 2014, other relevant ACA policy changes included implementation of the following: health insurance exchanges in all 50 states through either state or federally based marketplaces, prohibition of annual limits on health insurance coverage, and penalties for being a citizen without health care insurance (44). State-based marketplaces were prepared to begin enrollment on January 1, 2014; states without marketplace plans were defaulted to federally based marketplaces (45). Many of the state-based marketplace programs were in early adopter states of the ACA Medicaid Expansion, and, likewise, many of the federally based marketplaces were in non-adopter states. Although differences in care and outcomes for state versus federally operated marketplaces are not known, it is plausible that patients within states with planned marketplace programs had increased knowledge of policy changes and increased immediate access to insurance on the implementation date. Indeed, transplant center teams include financial coordinators who prospectively evaluate patients for sources of payment before listing, help patients identify payment sources, and seek rapid insurance approval for therapies (46). Second, the U.S. unemployment rate decreased throughout the study period (47), and a corresponding increase in private insurance may have affected the results. However, no sudden change in the unemployment rate was observed in 2014, and the increase in heart transplant listings among African-American patients with private insurance was not significant. Third, variation in transplant center density over time was considered as a factor. Although the data for this study had aggregate listings per states with de-identified center data, publicly reported data revealed no major changes in the number of active transplant centers during the study (111 centers in 2012 and 105 centers in 2015) (48). Similarly, there were no major differences between the 2 most populous states, which account for a large fraction of the data (Online Table 2), California (11 centers in 2012, 9 centers in 2013, 10 centers in 2014, and 11 centers in 2015), an early adopter state, and Texas (9 centers in 2012, 10 centers in 2013 to 2015), a non-adopter state (48).
First, the number of patients with end-stage heart failure who are eligible for heart transplant is not currently available. Thus, the U.S. census was used as the denominator for rate of heart transplant listing. Second, we do not control for the 15 early adopter states and Washington, DC, and the 4 non-adopter states that partially expanded Medicaid before the date of full ACA Medicaid Expansion (i.e., January 1, 2014). Excluding these states would have removed a large proportion of patients from the analysis. The effects of the ACA Medicaid Expansion may therefore be underestimated. Third, Medicaid insurance has high variability in state-level scope of service, quality of care, and reimbursement. This factor further affects the ability to achieve equity in access to heart transplant listings. Fourth, the ACA has not been in existence long enough to evaluate long-term outcomes such as wait-list mortality.
The rate of heart transplant listings after the ACA Medicaid Expansion differed according to race and ethnicity. The census-adjusted rate of heart transplant listings for African-American patients increased significantly in early adopting states compared with non-adopting states in January 2014. Listing rates increased marginally in Hispanic patients in non-adopter states, possibly due to ineligibility of undocumented Hispanic patients for the ACA Medicaid Expansion. There were no changes in rates of heart transplant listings in Caucasian patients at the time of the ACA Medicaid Expansion. This outcome suggests that broader expansion of the ACA may help mitigate racial/ethnic disparities in access to care.
COMPETENCY IN MEDICAL KNOWLEDGE: Underinsurance limits access to heart transplantations, especially among racial/ethnic minorities. Broadening insurance access with the ACA Medicaid Expansion was associated with increased heart transplant listing in African-American patients but not in Hispanic or Caucasian patients.
TRANSLATIONAL OUTLOOK: Further study of racial/ethnic changes in left ventricular assist device implantation after the ACA Medicaid Expansion is warranted.
The data reported here were supplied by the Minneapolis Medical Research Foundation as the contractor for the Scientific Registry of Transplant Recipients. The interpretation and reporting of these data are the responsibility of the authors and in no way should be seen as an official policy of or interpretation by the Scientific Registry of Transplant Recipients or the U.S. government. Dr. Breathett has received support from a T32 training grant (5T32 HL116276-02) from the National Institutes of Health and the University of Colorado, Department of Medicine, Health Services Research Development Grant Award. Dr. Allen discloses grant funding from the National Institutes of Health (K23 HL105896), the Patient Centered Outcomes Research Institute (CDR-1310-06998), and the American Heart Association (#16SFRN29640000); and has served as consultant for J&J, Novartis, St. Jude, and ZS Pharma. Dr. Daugherty has received grant funding from the National Heart, Lung, and Blood Institute (K08 HL103776) and the American Heart Association (#2515963). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Abbreviations and Acronyms
- Affordable Care Act
- confidence interval
- Scientific Registry of Transplant Recipients
- Received August 18, 2016.
- Revision received October 26, 2016.
- Accepted October 26, 2016.
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