Source of Post-Transplant Care and Mortality among Kidney Transplant Recipients Dually Enrolled in VA and Medicare

Discussion

In a cohort of kidney transplant recipients eligible to receive care in VA and/or the private sector using Medicare, more than 80% underwent transplantation at a non-VA Transplant Center using Medicare. However, two thirds received some or all post-transplant care within the VA. Patients who received post-transplant care exclusively through Medicare or through both VA and Medicare had higher mortality than those who received VA-only post-transplant care (7).

There are at least two potential non-mutually exclusive explanations for our findings of lower mortality among veterans who received VA-only post-transplant care. First, the quality of post-transplant care could be higher within the VA. Several prior studies that compared outcomes and quality of nontransplant care between VA and non-VA facilities demonstrated differences favoring VA (8⇓–10). Streja et al. (9) and Wang et al. (10) found lower mortality among veterans who received dialysis within the VA compared with veterans who received this treatment outside the VA. O’Hanlon et al. (8) demonstrated higher-quality diabetes, cardiovascular, and preventive care, and lower rates of inappropriate medication prescribing in VA compared with non-VA facilities. The provision of post-transplant care that minimizes risk for adverse outcomes requires effective coordination among providers, pharmacists, and transplant coordinators. Immunosuppressive agents must be properly dosed and interacting medications avoided, calcineurin inhibitor levels need to be maintained within narrow therapeutic windows, and transplant-related complications require prompt treatment. Several facets of the VA Healthcare System facilitate post-transplant care coordination that may be more challenging to achieve in the private sector. As a nationwide integrated health care system, the VA enables timely communication between providers at transplant centers and distant facilities. The capacity for telehealth visits in lieu of in-person examinations permits convenient and timely assessments by VA providers, and the universal electronic medical record allows providers to access test results and view prescribed medications anywhere within the VA (11,12). Such factors may contribute to more effective coordination of transplant care, which could translate into improved outcomes. Interestingly, the difference in 5-year mortality was smaller when post-transplant care was defined by immunosuppressant medication prescribing than by outpatient transplant-related clinic visits (Supplemental Table 5). As the venue of outpatient transplant visits may better reflect where veterans primarily receive their care, this finding suggests that potential differences in the quality of care could explain our primary findings.

Although we adjusted our analyses for site of transplantation and other potential confounders, an alternative explanation for our survival analyses favoring the VA may be due to transplant system and process differences, resulting in the favorable selection of patients in the VA. For example, VA Transplant Centers may require a more arduous evaluation process that results in the selection of healthier patients for transplantation compared with larger non-VA Centers. They may also be less likely to accept high Kidney Donor Profile Index kidneys, to minimize the number of patients with poor outcomes (13). Our finding of lower 30-day mortality among those transplanted within the VA may support this possibility. The lower rates of dialysis dependence and rejection episodes at 1 year, and lower frequency of outpatient transplant visits and calcineurin inhibitor measurements among those who received VA-only post-transplant care, a large majority of whom were transplanted in the VA, may also suggest a healthier patient population. However, these observations could also reflect differences in the quality of care after transplantation. Further exploration is needed to delineate the effects of post-transplant care quality and/or differential transplant listing on longer-term mortality among veterans receiving care within and across health care systems.

Many veterans in our study were users of dual care after transplantation, particularly those who received a kidney allograft through Medicare. Dual care poses a risk for fragmentation and/or duplication in care, as well as serious adverse outcomes (14⇓⇓⇓–18). Although the effect of dual care on outcomes among transplant recipients has not previously been investigated, a study by Thrall et al. (19) of 46 dual-care veterans with a history of organ transplantation found that more than half had duplicative monitoring of immunosuppressant levels and/or discrepancies in immunosuppressant regimens across health systems. Moreover, just 25% of kidney transplant patients had clinic notes or laboratory results from the non-VA facility scanned into the VA health record. Such dual care could plausibly lead to allograft rejection and other serious, adverse transplant-related complications. If so, this could explain why we found higher mortality among those who used dual post-transplant care compared with patients who were VA only. Nonetheless, our finding of lower mortality among dual-care patients compared with patients who are Medicare only suggests the possibility that some involvement from VA in post-transplant care might benefit patients. Future efforts to elucidate how coordination of transplant care affects patients’ outcomes may lead to improved treatment models in those eligible for care both within and outside VA.

The MISSION Act will enhance the convenience of kidney transplant care for many veterans by obviating the need to travel to a designated VA Transplant Center for such care. This is important as prior studies suggest that veterans without other health insurance were less likely to undergo kidney transplantation than veterans and non-veterans with private insurance (4,5). The extent to which veterans will choose to receive non-VA transplant care using the recently enacted MISSION Act is unknown. Nonetheless, our finding of higher long-term mortality among veterans who receive some or all post-kidney transplant care outside the VA underscores the importance of closely tracking outcomes among those who choose to utilize the MISSION Act to receive transplant care in the private sector.

The recently signed Advancing American Kidney Health Initiative aims to substantially increase the number of kidney transplants in the next decade, including instituting financial incentives and policy proposals to expand the kidney donor pool (20). Consequently, a growing number of patients, including veterans, are likely to receive transplant care in the future. Our findings on the substantial reliance of veterans on the VA for such care have important implications regarding the future allocation of funds to manage this patient population. Furthermore, future Centers for Medicare and Medicaid payment models and financial incentives could consider requirements for more integrated post-transplant care for the lifespan of the organ if additional research confirms that greater coordination of transplant care improves patient outcomes.

Our study has important limitations (13). First, although patients who received VA-only post-transplant care were more likely than patients who were Medicare only or dual care to have received a deceased donor transplant, we did not have access to other donor data such as Kidney Donor Profile Index, type of donor (standard criteria versus extended criteria), or recipients’ calculated panel-reactive antibody levels (21,22). Differences in such variables, if present, could affect longer-term outcomes. Nonetheless, the E-value associated with our lower point estimate (i.e., adjusted HR, 1.5; 95% CI, 1.1 to 2.1) suggests that an unmeasured confounder would need to have a HR of 2.37 to negate our findings, which seems unlikely (23). Second, we did not have access to data on post-transplant care paid for by private insurance and, hence, we did not include veterans who were eligible for but not enrolled in VA. Although administrative claims data should capture all such care, we were unable to identify immunosuppressant medication prescriptions in 12% of Medicare transplant patients in the year after transplant, despite their eligibility for continued Medicare payment of these medications (24). Third, we considered post-transplant care in the first 12 months after hospital discharge from transplantation as our exposure variable rather than a more sustained period of time, as the first year is typically the most intensive period of post-transplant management. Fourth, we selected a study endpoint (i.e., 5-year mortality) that is not the only potential quality of care outcome. We considered alternative outcomes, but limited power and lack of access to certain data sources precluded investigating other outcomes. Finally, we cannot confirm that the observed associations of post-transplant care source with death are causal. We also acknowledge that the post-transplant care veterans received using Medicare may not necessarily reflect the care they will receive with the MISSION Act. For example, care delivered via the MISSION Act will be documented as scanned notes in the VA electronic medical record, whereas Medicare-funded care has no such requirement.

In summary, in a national cohort of kidney transplant recipients dually enrolled in VA and Medicare, use of VA for post-transplant care is common, even among those undergoing transplantation outside VA, and is associated with lower mortality than receipt of such care via Medicare or both VA and Medicare. Future studies will help clarify the reason(s) for these differences. Nonetheless, our findings can inform patient decisions regarding the preferred venue of care after kidney transplantation and highlight the critical importance of monitoring patient outcomes as the VA expands options for care in the community.