JAMA publishes an article today (20th June), showing a surprisingly high rate of untreated kidney failure amongst adults. The study involved nearly 2 million adults in Canada and the rate was considerably higher amongst older adults.
The study was researched by Brenda R. Hemmelgarn, M.D., Ph.D., of the University of Calgary, Alberta, Canada, and colleagues whose aim was to determine if age is associated with the likelihood of treated kidney failure (renal replacement therapy: receipt of long-term dialysis or kidney transplantation) or untreated kidney failure, and all-cause mortality.
The patients were adults in Alberta, Canada, who had outpatient estimated glomerular filtration rate (eGFR; flow rate of filtered fluid through a kidney) measured between May 2002 and March 2008, with a baseline eGFR of 15 mL/min/1.73 m2 or higher. None of them required renal replacement therapy at the beginning of the study. The researchers looked for rates of treated kidney failure, untreated kidney failure (progression to eGFR <15 mL/min/1.73 m2 without renal replacement therapy), and death.
The researchers provide background information in the article, explaining that previous studies have defined kidney failure by receipt of long-term dialysis, which reflects both disease progression and a treatment decision. They go on to state that :
“Studies of the association among age, kidney function, and clinical outcomes have reported that elderly patients are less likely to develop end-stage renal disease (ESRD) compared with younger patients and are more likely to die than to progress to kidney failure even at the lowest levels of estimated glomerular filtration rate [...] Because it is plausible that the likelihood of initiating long-term dialysis among individuals with kidney failure varies by age, earlier studies may provide an incomplete picture of the burden of advanced kidney disease in older adults, based on the incidence of long-term dialysis alone.”
During the average follow up time of just under four and a half years, 5.4% or nearly 100,000 participants had died, over 3,000 or 0.18% developed and had kidney failure treated and around the same number 0.17% had untreated kidney failure. Within each eGFR level category, rates of death were higher with increasing age, while rates of treated kidney failure were higher amongst younger people. In the lowest eGFR reading of 15-29mL/min/1.73 m2 treated kidney failure rates were ten fold higher amongst the youngest age group, defined as 18 to 44, compared with the oldest group, 85 or older.
The relationship was clearly reversed for untreated kidney failure with untreated failures 5 times higher amongst the over 85 group, compared to the 18-44 year old group.
Researchers conclude that:
“These findings have important implications for clinical practice and decision making; coupled with the finding that many older adults with advanced chronic kidney disease [CKD] are not adequately prepared for dialysis, these results suggest a need to prioritize the assessment and recognition of CKD progression among older adults. Our findings also imply that clinicians should offer dialysis to older adults who are likely to benefit from it [...] and should offer a positive alternative to dialysis in the form of conservative management (including end-of-life care when appropriate) for patients who are unlikely to benefit from (or prefer not to receive) long-term dialysis. Given the large number of older adults with severe CKD, these results also highlight the need for more proactive identification of older adults with CKD, assessment of their symptom burden, and development of appropriate management strategies. Finally, our study demonstrates the need to better understand the clinical significance of untreated kidney failure, the factors that influence dialysis initiation decisions in older adults, and the importance of a shared decision making process for older adults with advanced CKD.”
“Rates of Treated and Untreated Kidney Failure in Older vs Younger Adults” JAMA. 2012;307(23):2507-2515. doi:10.1001/jama.2012.6455