(CNN) -- A new study of pediatric care finds wide regional variations in the kinds of treatment and medication children receive, which is "raising troubling questions," according to its authors.
The Dartmouth Atlas report released Wednesday replicates and expands upon a groundbreaking study done in the 1970s.
Back then, scientists discovered a wide variety of care for children with throat problems. The 1970s study found 60% of the children who lived in Morrisville, Vermont, had their tonsils out by the age of 15. In other communities, fewer than 20% of kids in that same age group did.
The variety surprised researchers, and the previous study had a big impact on children's health care in the region. Doctors reexamined their practices and tried to establish exactly why there was such variation. The number of surgeries declined, and the rate of tonsillectomies in Morrisville fell to one of the lowest in the state.
Researchers wanted to revisit the same issue using current data to see if the regional variations in care continued. Again, they found a wide variety in the quantity and quality of children's care.
Researchers focused on the northern New England area, since state legislatures in Maine, Vermont, and New Hampshire require medical claims reporting. In many other parts of the country, there is no such requirement for reporting data, which has created a data gap for researchers.
"The regional differences are striking here," said Dr. David Goodman, professor of pediatrics at the Dartmouth Institute and an author of the report. "What makes this particularly striking is the data we now have is so vivid detail, we can identify the very hospitals" at the heart of the variations.
Looking at tonsillectomies again, researchers found that there is still a wide regional variety in how many are performed.
Tonsillectomies are mostly done in children with problems with sleep apnea or for kids who suffer from chronic sore throats.
Randomized trials show these surgeries have limited effectiveness. Consequently, fewer tonsillectomies had been performed since the 1960s when the rate peaked, but researchers have noticed a small upward trend between 1996 and 2006. The rate rose from 4.97 to 8.7 per 1,000 children (that's 243,000 procedures per year).
Rates in the region did vary significantly. They were lowest in Bangor, Maine, at 2.7 per 1,000, compared with Berlin, New Hampshire, where the rate was nearly four times higher.
"These surgeries are fairly common in younger children, where there are absolutely no studies showing that this is beneficial, and even with older children, the beneficial effects are quite small," Goodman said. "What this shows is that whether a child has this surgery depends more on where they get their care as opposed to who they are."
The report looked beyond tonsillectomies. The authors also looked at the number of well-care visits children had, what kind of tests they were given, and what kind of prescriptions they received.
Again, researchers continued to find a wide variety of treatments across the region. For instance, when it came to adolescents' annual doctor visits, 55% of teens in Lebanon, New Hampshire, annually saw a doctor, versus only 29% of teens in Colebrook, New Hampshire.
Children were screened for lead exposure in varying numbers as well. While 86% of children under the age of 2 were screened in Berlin, New Hampshire, between 2008 and 2010, only 8% were tested in Dover-Foxcroft, Maine.
ADHD care also seemed to have wide differences. Medication rates varied more than twofold, with more than 75 per 100 children in Caribou, Maine, compared with less than 35 per 100 children receiving it in Greenville, Maine. (Nationally, only 8.4% of children ages 3-17 were ever diagnosed with ADHD through 2009, the latest year available in a 2011 survey by the Centers for Disease Control and Prevention).
What this suggests, according to the Dartmouth study authors, is that children are being under-treated in some areas and over-treated in others.
Goodman said there is intense interest from doctors and hospitals in the region in the findings of this report.
"They want to understand what is occurring and to use this information to improve care," he said.
He also hopes that other state legislatures will now make this kind of data collection on care mandatory. "We'd like for other states to realize the value of this data and know that its collection is important for the well-being of their population."