Clinical Trials in Nephrology

Dr. Uptal Patel

Dr. Uptal Patel

Over the last decade, there has been increased recognition that clinical trials in nephrology are fewer in number and smaller in size when compared to other medical specialties. However, a more contemporary examination of published and ongoing clinical trials in nephrology has been missing. In a recent article published in AJKD, Inrig et al systematically reviewed the database and provide a contemporary snapshot of randomized trials in nephrology. Corresponding author Dr. Uptal Patel (UP) discusses this study with Dr. Navdeep Tangri (eAJKD), eAJKD Contributor.

eAJKD: What prompted you to undertake this study?

UP: As of 2007, the FDA Amendments Act legislation required registration and recording of basic results of clinical trials of anything regulated by the FDA stating that it should be freely accessible. This provided an opportunity to do something that hadn’t been done, which was looking at studies irrespective of their ultimate outcome with respect to publication. There have been some reviews in our field about the quality, content, and scope of randomized trials in nephrology, but looking at the pipeline had not been recently done.

eAJKD: What would you say was the key finding of your study?

UP: On the positive side, there were a number of trial characteristics in the nephrology studies that we found to be similar to studies in other subspecialties (for example, rates of randomized versus nonrandomized trials). When compared to the cardiology studies, there were some with better study characteristics but there is still room for improvement. There were a number of study characteristics that remained suboptimal within nephrology studies (for example, a large number of unblinded studies and a small number of studies with data monitoring committees), indicating that we still have some work to do despite the call for action from prior studies and the renal community.

eAJKD: One of the things that struck me is that enrollment is always lower in nephrology trials. What are some of the reasons we do smaller studies?

UP: I think we do smaller studies in nephrology because there are a number of barriers to doing larger studies.  This is something we can hopefully come together on as a community.  Cardiology has done a number of innovative things, and they are on the brink of changing the way clinical trials are done.

As an example, there are a number of registries in the cardiology space that have been used to improve quality of care and reduce variation.  These have demonstrated improvements in quality of care and health outcomes. Cardiology is now leveraging that same robust data collection infrastructure to help make randomized trials more efficient.  For example, a trial was recently completed that randomized women to radial versus femoral PCI, at about 10 percent of the cost due to its innovative use of existing registries.

Why can’t we do that in nephrology? We have registries for our ESRD and transplant populations, yet they haven’t developed into platforms for clinical trials. They’ve remained largely administrative databases and not real-time, functional, useful registries for improving patient care or for better studying our patients.

eAJKD: Did you measure whether trials evaluated a clinical versus a surrogate outcome?

UP: We did not. And, hopefully, that will be something we can do later. The reason is that the reporting structure of includes outcomes as unstructured data, so it requires manual coding and data extraction. But, I agree that we as a field need to study more meaningful clinical outcomes.

To view the article abstract or full-text (subscription required), please visit

Leave a Reply