Publication Spotlight: Dr. Orandi
Read the below interview with Babak John Orandi, MD, PhD, MSc, Assistant Professor, School of Medicine - Surgery, University of Alabama Birmingham Medical Center and author of Obesity as an isolated contraindication to kidney transplantation in the end-stage renal disease population: A cohort study.
What question did your study aim to answer?
We sought to estimate the number of people on dialysis who have obesity as the sole contraindication to listing for kidney transplant.
What inspired you to conduct this study?
With the growing number of patients on dialysis and the rising obesity epidemic, by 2030 nearly 50% of U.S. adults will have obesity and nearly 25% will have severe obesity—many patients have obesity as a major barrier to transplantation. In my practice, I am increasingly encountering the clinical challenge of assisting patients with both end-stage renal disease and obesity achieving the benefits of kidney transplantation.
Which USRDS datasets did you use to conduct your study?
1/1/2012-12/31/2014. We used information from the Patient file to identify and then exclude patients who within 90 days after their first ESRD service date: died, received a kidney transplant or were added to the kidney/KP waitlists. Among the ESRD patients that remained eligible for inclusion, USRDS identifiers linked to the ESRD CORE RXHIST file identified patients that had recovered, discontinued dialysis, or been lost to follow-up within 90 days after their first ESRD service date. Further exclusions based on patients' comorbidities identified within 90 days of first ESRD service date that contraindicated transplantation. We identified psychological, medical, and functional status comorbidities based on information in the USRDS Core SAF dataset's MEDEVID file, and diagnosis codes from the 2012-2014 Physician/Supplier claims data.
Our primary exposure was BMI at first ESRD service date from the USRDS Core SAF dataset's MEDEVID file. Primary outcome information, e.g., wait-listing, transplantation, death, and information on most potential confounders were from the 2019 USRDS Core SAF dataset's Patient file; however, among those added to the waitlist and analyzed for time to transplantation, we obtained PRA information from the kidney and kidney-pancreas waitlist files.
Using plain language, please summarize your study conclusions in two or three points.
Nearly 40,000 incident dialysis patients from 2012-2014 had obesity as the only contraindication to wait-listing for kidney transplant. These patients were more likely to be Black, female, and younger.
Please share a specific insight about working with USRDS data that you learned during the completion of this study.
Many of the challenges of working with USRDS data can be managed by first referring to and understanding the available documentation, e.g., the "2019 Researcher’s Guide to the USRDS Database." Nonetheless, some of the data files, e.g., claims data, are quite large and require adequate computer resources.