Medical Professional Publications

Rise in Pediatric Kidney Stones Sparks Concerns

(From the May 2015 Issue of PediatricsOnline)

Researchers at Nationwide Children's Hospital find troubling trends in pediatric urolithiasis — the formation of kidney stones — reaching throughout the healthcare system. Their review of national hospital data, published in the journal Pediatric Nephrology, shows evidence that increasing numbers of children are suffering from stones and the burden on the system is growing.

Theirs is one of three recent studies — each using different data sources — that found significant increases. In this review, nearly 70 percent of cases were handled in the emergency room, where the number of cases increased by 9 percent from 2006 to 2011. Earlier works found the number of pediatric kidney stone cases nearly doubled in South Carolina from 1996 to 2007, and nationally, case numbers grew by an adjusted 10.6 percent annually from 1999 to 2008.

These increasing numbers offer a strong argument for increased research, the authors say.

The reason: "In adults, there's strong evidence that there are a lot of extra-renal health problems associated with kidney stones," says Kirsten Kusumi, MD, a fellow in the Section of Nephrology at Nationwide Children's and lead author of the study. "Adult patients have been shown to have higher rates of heart attack, stroke, coronary artery disease and congestive heart disease, as well as chronic kidney disease and low bone density."

The researchers are pursuing studies to determine whether the pediatric urolithiasis has the same associations with these serious health problems.

Dr. Kusumi and her team evaluated data from the Kid's Inpatient Database of the Healthcare Costs and Utilization Project (HCUP) from six years between 1997 and 2012 and the HCUP National Emergency Department Sample from 2006 to 2011. HCUP provides data from a sample of American pediatric hospitals. The study took into account nephrolithiasis, which is formation of stones in the kidney, as well as ureterolithiasis, stones found in the ureter.

In addition to rising numbers of pediatric cases, they found that costs have also been climbing despite a shift toward outpatient treatment, indicated by increasing emergency department visits combined with decreasing inpatient admissions.

"The good news is we're getting better at managing kidney stones," Dr. Kusumi says. The data indicate that the most serious cases are concentrated in inpatient care.

The average number of pediatric hospital discharges for urolithiasis decreased overall by 2.5 percent from 1997 to 2012. During that time, the average stay for nephrolithiasis dropped by nearly 10 hours and the average stay for ureterolithiasis, which is generally harder to treat, increased by 5 hours.

Despite the shift toward more outpatient care, total aggregate charges increased from $8.3 million to $17.6 million, an increase of 20 percent when adjusted for inflation.

Within the overall figures, the cost of inpatient treatment of nephrolithiasis rose 300 percent and inpatient ureterolithiasis 238 percent.

A surprising finding by the team is that, while males are most likely to be affected as adults, teenage females are the most common among pediatric patients. The reason for this is unknown, but the team hypothesizes that sex hormones may be playing a role.

The authors believe the study adds to the call for increased research in kidney stones in children, and they are seeking National Institutes of Health (NIH) grants to investigate these trends further.

"Knowing adults with urolithiasis have long-term complications, it's concerning that more and more children are seen with this disease," Dr. Kusumi says.

"Nobody has really considered these extra-renal complications in children," she continues. "That’s what we are currently working on to improve the health of our patients."


Kusumi K, Becknell B, Schwaderer A. Trends in pediatric urolithiasis: patient characteristics, associated diagnoses, and financial burden. Pediatric Nephrology. 2015 May, 30(5):805-810.

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