Costs and Outcomes of Privately-Insured Kidney Transplant Recipients by Body Mass Index

Obesity presents an additional challenge to the procedure of and recovery from kidney transplantation. As the prevalence of transplant candidates with an elevated body mass index (BMI) grows, researchers need to examine and quantify the increased risks and additional costs associated with the full spectrum of body composition.

A retrospective cohort study design was used.

Data from a private health insurance provider were linked with records from the Organ Procurement and Transplantation Network to examine costs and health outcomes following kidney transplantation.

BMI was used to predict costs and outcomes.

The primary outcome of interest was posttransplant cost defined as insurance charges. Secondary outcomes of interest included delayed graft function, graft failure, patient survival, and length of transplant hospitalization.

Categories of BMI followed selected cutoffs from World Health Organization International Classifications. Charges from recipient dialysis center, health providers, and treatment centers following transplant were summed during transplant hospitalization as well as each of three years following transplantation.

Rates of graft failure were significantly increased for underweight, overweight, obese, and morbidly obese recipients. Recipients with elevated BMI had a significantly longer length of transplant hospitalization and an increased rate of delayed graft function.

Our analysis was limited to the quality and availability of the data included in the registry. Though inexpensive and easy to calculate, BMI may not be the best measure of body composition. Finally, BMI measurement is cross-sectional at time of transplant thereby limiting the potential for fluctuation of BMI before and after transplantation.

The study results highlight the exponential concern associated with non-normal BMI for kidney transplant recipients. Transplant centers and insurance companies should consider funding weight management programs for transplant candidates as a means of obtaining preferred BMI and reducing costs associated with follow-up care.