Trends in the Medical Complexity and Outcomes of Medicare-insured Patients Undergoing Kidney Transplant in the Years 1998-2014

Using Relative Survival to Estimate the Burden of Kidney Failure

RATIONALE & OBJECTIVE

Estimates of mortality from kidney failure are misleading because the mortality from kidney failure is inseparable from the mortality attributed to comorbid conditions. We sought to develop an alternative method to reduce the bias in estimating mortality due to kidney failure using life table methods.

STUDY DESIGN

Longitudinal cohort study.

SETTING & PARTICIPANTS

Using data from the US Renal Data System and the Medicare 5% sample, we identified an incident cohort of patients, age 66+, who first had kidney failure in 2009 and a similar general population cohort without kidney failure.

EXPOSURE

Kidney failure.

OUTCOME

Death.

ANALYTICAL APPROACH

We created comorbidity, age, sex, race, and year-specific life tables to estimate relative survival of patients with incident kidney failure and to attain an estimate of excess kidney failure-related deaths. Estimates were compared with those based on standard life tables (not adjusted for comorbidity).

RESULTS

The analysis included 31,944 adults with kidney failure with a mean age of 77±7 years. The 5-year relative survival was 31% using standard life tables (adjusted for age, sex, race, and year) versus 36% using life tables also adjusted for comorbidities. Compared with other chronic diseases, patients with kidney failure have among the lowest relative survival. Patients with incident kidney failure ages 66-70 and 76-80 have a survival comparable to adults without kidney failure roughly 86-90 and 91-95 years old, respectively.

LIMITATIONS

Relative survival estimates can be improved by narrowing the specificity of the covariates collected (eg, disease severity and ethnicity).

CONCLUSIONS

Estimates of survival relative to a matched general population partition the mortality due to kidney failure from other causes of death. Results highlight the immense burden of kidney failure on mortality and the importance of disease prevention efforts among older adults.

PLAIN-LANGUAGE SUMMARY

Estimates of death due to kidney failure can be misleading because death information from kidney failure is intertwined with death due to aging and other chronic diseases. Life tables are an old method, commonly used by actuaries and demographers to describe the life expectancy of a population. We developed life tables specific to a patient's age, sex, year, race, and comorbidity. Survival is derived from the life tables as the percentage of patients who are still alive in a specified period. By comparing survival of patients with kidney failure to the survival of people from the general population, we estimate that patients with kidney failure have one-third the chance of survival in 5 years compared with people with similar demographics and comorbidity but without kidney failure. The importance of this measure is that it provides a quantifiable estimate of the immense mortality burden of kidney failure.

Declining Medicare reimbursement in abdominal transplantation from 2000 to 2021

BACKGROUND

The Centers for Medicare and Medicaid Services is a major payer for abdominal transplant services. Reimbursement reductions could have a major impact on the transplant surgical workforce and hospitals. Yet government reimbursement trends in abdominal transplantation have not been fully characterized.

METHODS

We performed an economic analysis to characterize changes in inflation-adjusted trends in Medicare surgical reimbursement for abdominal transplant procedures. Using the Medicare Fee Schedule Look-Up Tool, we performed a procedure code-based surgical reimbursement rate analysis. Reimbursement rates were adjusted for inflation to calculate overall changes in reimbursement, overall year-over-year, 5-year year-over-year, and compound annual growth rate from 2000 to 2021.

RESULTS

We observed declines in adjusted reimbursement of common abdominal transplant procedures, including liver (-32.4%), kidney with and without nephrectomy (-24.2% and -24.1%, respectively), and pancreas transplant (-15.2%) (all, P < .05). Overall, the yearly average change for liver, kidney with and without nephrectomy, and pancreas transplant were -1.54%, -1.15%, -1.15%, and -0.72%. Five-year annual change averaged -2.69%, -2.35%, -2.64%, and -2.43%, respectively. The overall average compound annual growth rate was -1.27%.

CONCLUSION

This analysis depicts a worrisome reimbursement pattern for abdominal transplant procedures. Transplant surgeons, centers, and professional organizations should note these trends to advocate sustainable reimbursement policy and to preserve continued access to transplant services.

Effect of pretransplant dialysis vintage on clinical outcomes in deceased donor kidney transplant

The waiting time for deceased donor kidney transplants (DDKT) is increasing. We evaluated DDKT prognosis according to the pretransplant dialysis vintage. A total of 4117 first-time kidney transplant recipients were enrolled from a prospective nationwide cohort in Korea. DDKT recipients were divided into tertiles according to pretransplant dialysis duration. Graft failure, mortality, and composite were compared between DDKT and living donor kidney transplant (LDKT) recipients. Pretransplant dialysis vintage was longer annually in DDKT recipients. In the subdistribution of the hazard model for the competing risk, the first tertile did not show an increased risk of graft failure compared with LDKT recipients; however, the second and third tertile groups had an increased risk of graft failure compared to LDKT recipients (adjusted hazard ratio [aHR] 3.59; 95% confidence interval [CI] 1.69-7.63; P < 0.001; aHR 2.37; 95% CI 1.06-5.33; P = 0.037). All DDKT groups showed a significantly higher risk of patient death than LDKT, with the highest risk in the third tertile group (aHR 11.12; 95% CI 4.94-25.00; P < 0.001). A longer pretransplant dialysis period was associated with a higher risk of the composite of patient death and graft failure in DDKT recipients. DDKT after a short period of dialysis had non-inferior results on graft survival compared with LDKT.

Revision Total Hip Arthroplasty in Solid Organ Transplant Patients: A Propensity Score-Matched Cohort Study for Aseptic and Infected Revisions

Background

Previous studies have demonstrated that solid organ transplant (SOT) patients undergoing primary total hip arthroplasty (THA) are at an increased risk of postoperative complications. The purpose of this study is to use a large, national database to investigate revision THA (rTHA) outcomes in SOT patients.

Methods

Nationwide Readmissions Database (NRD) from 2010-2018 was used, and ICD-9 and ICD-10 codes were used to identify all patients who underwent rTHA, including those with history of SOT. Propensity score matching (PSM) was used to analyze rTHA outcomes in SOT patients comparted to matched controls. Separate analysis performed for patients undergoing rTHA for prosthetic joint infection (PJI) vs other causes.

Results

A total of 414,756 rTHA, with 1837 of those being performed in SOT patients, were identified. Of these, 65,961 and 276 were performed for PJI in non-SOT and SOT patients, respectively. For non-PJI patients, SOT patients had higher 90-day all-cause readmission rates (24.0% vs 19.4%, P = .03) but lower rate for readmission related to rTHA (6.0% vs 9.2%, P = .03), but no difference readmission for specific rTHA complications, mortality (0.6% vs 1.3%, P = .20), or revision rTHA. Of PJI patients, SOT patients had no difference in overall 90-day readmission (38.6 vs 31.3%, P = .280), readmission for specific rTHA complications, re-revision, or mortality (4.7% vs 6.0%, P = .63).

Conclusions

SOT patients undergoing rTHA for aseptic reasons are higher risk of overall readmission but lower risk of readmission related to rTHA than appropriately matched controls. SOT PJI patients undergoing had similar rates of readmission, mortality, and revision surgery compared to matched non-SOT PJI patients.

Health claims databases used for kidney research around the world

Health claims databases offer opportunities for studies on large populations of patients with kidney disease and health outcomes in a non-experimental setting. Among others, their unique features enable studies on healthcare costs or on longitudinal, epidemiological data with nationwide coverage. However, health claims databases also have several limitations. Because clinical data and information on renal function are often lacking, the identification of patients with kidney disease depends on the actual presence of diagnosis codes only. Investigating the validity of these data is therefore crucial to assess whether outcomes derived from health claims data are truly meaningful. Also, one should take into account the coverage and content of a health claims database, especially when making international comparisons. In this article, an overview is provided of international health claims databases and their main publications in the area of nephrology. The structure and contents of the Dutch health claims database will be described, as well as an initiative to use the outcomes for research and the development of the Dutch Kidney Atlas. Finally, we will discuss to what extent one might be able to identify patients with kidney disease using health claims databases, as well as their strengths and limitations.