The cost of children’s health care is growing quickly — especially for baby boys.

In 2013, per capita spending on health care for babies, infants and toddlers between the ages of 0 and 3 was $4,813, according to a study of health insurance claims released this month.

That’s a bigger number than average spending for many working-age adults, the report stated, and it’s up about 19 percent from per capita spending for babies just three year’s earlier.

But what’s even more intriguing to some physicians and health researchers is a large gender gap behind the numbers.

Per capita spending for boys in the age group was $5,307, according to the study, whereas average spending for girls was $4,294.

A difference of more than $1,000 is “beyond what I expected,” said Dr. David Griffin, a medical director and pediatrician with Bloomington-based HealthPartners.

The study didn’t include data from HealthPartners, so Griffin called up numbers from his own company.

“Our information perfectly parallels what this shows,” he said. “Our comparable numbers are $4,023 for boys and $3,200 for girls. So, we’re lower, but the ratios are the same.”

So what explains it?

The study from researchers at a nonprofit called the Health Care Cost Institute described broad trends in health care spending for children, and found overall that the rate of increase for those ages 0 to 18 exceeded that for the under-65 population overall.

The data come from claims handled by four of the nation’s largest health insurers — Aetna, Humana, Kaiser Permanente and Minnetonka-based UnitedHealth Group — and covers only children in employer-sponsored health plans. Those insurers are financial backers of the research institute.

The report drew on claims data from about 10.2 million children per year, and looked at spending in broad categories such as acute hospital inpatient services, professional procedures, brand prescriptions and generic prescriptions. In almost all categories, spending for boys age 0 to 3 exceeded spending for girls.

The data include hints about possible drivers of the difference, such as more emergency room spending and use for baby boys than baby girls.

But the report itself doesn’t answer specific questions like: Could the overall spending difference be driven by the cost of circumcisions for boys, or fewer problems with premature birth for baby girls?

“I can tell you things about use of services, average price of services, because we have the actual allowed amounts of the services that people used,” said Amanda Frost, senior researcher with the institute. “However, claims data is not very good at telling us why these things occurred.”

The documented gender gap in ER spending, as well as prescription medication costs, jumped out at Katherine Cairns, executive director for the Minnesota Chapter of the American Academy of Pediatrics.

Baby boys used emergency rooms in 2013 at a rate of 300 visits per 1,000 insured, compared with 254 visits per 1,000 insured for baby girls, according to the report. The average price of an ER visit was $922 for baby boys, compared with $908 for baby girls.

Higher spend on ER, drugs

Cairns noted the report showed higher spending on ERs and pharmaceuticals not just for baby boys, but for boys through the age of 13. The take- home message, Cairns said, is that parents can play an important role in preventive care and safety that will “help decrease emergency room visits and the associated costs.”

Dr. Thomas George, a neonatology specialist at the University of Minnesota Medical Center, seconded the point. Colleagues in emergency medicine at the U say that boys account for about 60 percent of all injuries, compared with 40 percent for girls, across all ages, George said.

But in terms of babies, George thinks the gender gap in spending is likely driven by costly health care for babies born premature.

In 2014, boys accounted for about 57 percent of infants admitted to the neonatal intensive care unit at the University of Minnesota Masonic Children’s Hospital. Boys made up a similar majority for the last four years, George said, adding that an international database shows a similar pattern.

“It’s a known phenomenon that girls do better than boys in the NICU setting,” he said, referring to neonatal intensive care units. “And some of those complications of prematurity … those are long-term consequences, so I would expect then those boys who have those complications to just require more health care.”

While there are theories on gender differences that might explain NICU outcomes, there also are many unknowns, said Roxanne Fernandes, chief nursing officer at Children’s Hospitals & Clinics of Minnesota. Whether it’s differences in metabolizing medications or signs of heart attack, “I think we’re just beginning to understand those gender differences,” said Fernandes, who was a NICU nurse back in 1979.

If NICU costs are the driver, the dollars are justified by dramatic improvements in survival rates for premature babies, Fernandes said.

“How we treat these babies, both before birth and after birth, is so different from the way we treated them 40 years ago — it’s remarkable,” she said.

What about circumcision?

Circumcision costs could be in the mix, but Fernandes said she wasn’t sure it would be a big factor. Some insurers don’t pay for circumcision, she said, while others have pushed for circumcisions to be performed outside of hospitals, where procedures can be more costly.

While HealthParters hopes to do more analysis on the gender gap, Griffin says his bet is that NICU costs explain it. And if that’s the case, it’s another reason to focus efforts on preventing prematurity and low birth weight by promoting healthy pregnancies, he said.

– since the costs seem excessive – the NICU factor could explain it.

“Anytime we’re looking at costs related to childbirth, there’s a huge range around those averages — they can be strongly driven by outliers,” said Katy Kozhimannil, a health policy researcher at the University of Minnesota. “While the majority of births go well and are uncomplicated, the ones that are not can be incredibly costly, because it’s some of the most intensive medical care that we provide.”


Twitter: @chrissnowbeck