'Kidney' vs 'Renal': Experts Say Words Matter

Marlene Busko

November 06, 2020

The KDIGO consensus report for nomenclature for kidney function and disease recommends largely replacing the word "renal" with "kidney" instead, but there has been pushback, especially when it comes to making this semantic switch in nephrology journals.

The report by Andrew S. Levey, MD, Tufts Medical Center, Boston, Massachusetts and colleagues, published online in Kidney International, grew out of a Kidney Disease: Improving Global Outcomes (KDIGO) consensus conference attended by nephrology journal editors, researchers, and clinicians in June 2019. 

Medscape interviewed several stakeholders to find out their views about the recommended new kidney lingo.

Most Patients Don't Know What Renal Means

KDIGO collaborated with Standardised Outcomes in Nephrology (SONG) to conduct 10 focus groups with 54 patients and 13 caregivers from the United States, United Kingdom, and Australia. These revealed the patients' attitudes and experiences with language commonly used to describe kidney diseases and care.

Some patients said that "end-stage kidney disease" sounds like impending death, and most did not know what "renal" meant.

KDIGO nomenclature conference participants

The full article, by SONG cofounder Allison Tong, PhD, MPH, University of Sydney, Australia, and colleagues, was later published in the Clinical Journal of the American Society of Nephrology (CJASN) and was praised in a Patient Voice editorial by Paul Conway, chair of policy and global affairs at the American Association of Kidney Patients.

Conway told Medscape: "I think if you change language and make it more readily understood as a policy and healthcare issue, you could save lives because people will be more attuned."

"To drive innovation like artificial implantable kidneys, you will need to capture the imagination of the American public and investors and Congress," he added.

Key KDIGO Recommendations in Five Areas

The main nomenclature recommendations from the consensus conference are to:

  • Use "kidney" rather than "renal" or "nephro-" when referring to kidney disease and kidney function, except when describing specific kidney disease (eg, membranous nephropathy) or structure (eg, renal artery)

  • Use "kidney failure" with appropriate descriptions of presence or absence of symptoms and signs rather than "end-stage kidney disease" and use kidney replacement therapy rather than renal replacement therapy

  • Follow the 2012 KDIGO definition and classification of acute kidney diseases and disorders and acute kidney injury

  • Follow the 2013 KDIGO definition and classification of chronic kidney disease

  • Use specific terms such as albuminuria, proteinuria, or decreased glomerular filtration rate to describe stage of disease, rather than "abnormal" or "reduced" kidney function

Dr Andrew Levey in a webinar on the nomenclature recommendations.

A corresponding five-part glossary provides extensive, detailed recommendations. Part of this glossary will be added to the American Medical Association's online manual of style.

Are the Nephrology Journals Onboard?

The recommendations were developed by consensus with input from more than 20 journal editors, and the executive summary and glossary was published in many journals.

Conference participant Joseph Laycock, PhD, managing editor of Pediatric Nephrology, London, UK, told Medscape that the key changes are to use "kidney" preferentially over "renal" where reasonable, and to replace the term "end-stage" with the more accurate term "stage 5 chronic kidney disease" or "kidney failure."

Since many terms such as 'renal transplant' and 'kidney transplant' are used interchangeably, "let's pick the one most patients understand," he said.

In an editorial published published in May, Laycock acknowledged however that the switch is not always reasonable, "such as in specific diseases, anatomical terms, societies, or indeed our journal name."  

According to Laycock all of the nephrology journals are endorsing the glossary and implementing the key points, albeit not in exactly the same way.

Not All Nephrologists, Editors, or Patients Agree

Nephrologists polled by Medscape have varying views on the proposed changes. Matthew Sparks, MD, from Duke University and the Durham VA, North Carolina, who participates in the nephrology journal club Freely Filtered podcast, is "tirelessly working to ensure 'renal' is erased from our memories."  

"I've taken up the charge to push this issue," he told Medscape. "I think it is a very important one."

Dr Matthew Sparks

The concept is not new, Sparks noted. For example, the national meeting of the American Society of Nephrology (ASN) was previously called Renal Week. It was switched to Kidney Week in 2011 once the organizers realized that those living in the city hosting the convention had no idea what "renal" meant.

Sparks understands why critics trivialize the issue, but for him even these small things matter.

His fellow Freely Filtered podcaster Swapnil Hiremath, MD, from the Ottawa Hospital Research Institute, Ottawa, Canada, takes a different stance. "This is a faux debate that takes time and effort and attention away from the real issues," he told Medscape.

He believes time would be better spent "developing new therapies, trying to get more patients transplanted, and fixing racial and socioeconomic inequities."

Hiremath also finds the move to use the term "kidney" somewhat Anglophilic and very American. The kidney is "la rein" in French, he noted, and in much of the non-English speaking world renal is understood by patients.

For him, "renal replacement therapy (RRT)" rolls off the tongue much more easily than "kidney replacement therapy (KRT)."

Less controversial is the recommendation to avoid using "end-stage." As Laycock noted, that term has been defunct since the KDIGO 2012 criteria, "added to the fact that patients potentially find it distressing, its removal is overdue."

Roger A. Rodby, MD, Rush University, Chicago, Illinois, agrees. It's "a terrible term for people to hear. 'End stage' sounds like death, and originally that's what it meant, but now we've got options. We've got great dialysis [and] transplant," he told Medscape.

However, Rodby also thinks the other recommendations go too far and is not convinced that changing renal to kidney really improves anything.

Some patients agree. Californian Lori Hartwell, the founder and president of Renal Support Network and the host of KidneyTalk, a radio podcast show, told Medscape: "If they [KDIGO] want to use kidney instead of other terms, great — but don't impose it on the rest of us."

Hartwell, who was diagnosed with kidney disease at age 2, added, "When you have an illness, you have to learn a new vocabulary with all the complex terminology to survive and thrive."

She is more concerned about the designated stages for chronic kidney disease because it mimics the stages of cancer. "Kidney decline is a natural function of aging. This naming of stages scares people who may be perfectly fine for their age or circumstances," she observed.           

And Kamyar Kalantar-Zadeh, MD, PhD, MPH, University of California Irvine School of Medicine and editor in chief of the Journal of Renal Nutrition, is strongly opposed to replacing "renal" with "kidney" throughout nephrology journal articles.

Despite the good intentions of the conference participants, he told Medscape, "the proposed nomenclature is limiting and undermines technical complexities of the scientific language of the great field of kidney medicine."

He was on board with earlier calls from the National Kidney Foundation to use the word kidney more often, especially when communicating with patients and the public at large.

"However, KDIGO, which is subject to no defined oversight or accountability by any professional society or patient groups, is going to [the] extreme," he said. Even more extreme, he asserts, are nephrology journals such as CJASN that refuse to publish papers that do not follow the imposed glossary. 

Nephrology Leading The Way

The KDIGO consensus report author, Levey, told Medscape that he anticipates that this will be a gradual process, probably over years.

And while nephrology has taken the lead by involving patients to revise and improve its terminology, SONG cofounder Tong thinks that other specialties may follow suit.

"I suspect this will be part of a trend to standardize [medical] terms in communication," Levey echoed. 

Do you have a strong preference for the use of either 'kidney' or 'renal' in journals or communication with patients? If so, let's discuss in the comments.

The consensus conference was sponsored by AstraZeneca, Boehringer Ingelheim, Fresenius Medical Care, Bayer Health Care, Sanofi, and Roche.

Marlene Busko is an independent medical journalist who specializes in reporting about diabetes and endocrinology, cardiology, and nephrology. She lives in Montreal, Canada and enjoys hiking, biking, and skiing.

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