One in 7 people with Type 2 diabetes may be needlessly testing their blood sugar at home several times a day, a U.S. study says.

People with Type 2 diabetes don't need to test their blood at home if they have well-controlled symptoms and don't take medications that can cause dangerously low blood sugar, doctors say. For these patients, studies have not found that home blood sugar monitoring makes any difference in blood sugar levels. But still, many of them are pricking their fingers unnecessarily.

The researchers examined data on more than 370,000 people with Type 2 diabetes. Overall, almost 88,000, or about 23 percent, had at least three insurance claims for test strips used to check blood sugar at home.

More than half of the people testing their blood sugar at home didn't need to do this, accounting for 14 percent of the total study population, researchers reported Monday in JAMA Internal Medicine.

"Many Type 2 diabetes patients not using insulin or other medications at risk of rapid changes in blood sugar levels are testing far more often than they need to be," said the lead study author, Dr. Kevin Platt of the University of Michigan in Ann Arbor.

"This needless behavior causes unnecessary pokes, worry and costs," Platt said by email. "More is not always better when it comes to medical care."

Type 2 diabetes, the most common form of the disease, is linked to obesity and aging and develops when the body can't properly use or make enough of the hormone insulin to convert blood sugar into energy. Left untreated, it can lead to complications like blindness, kidney failure, nerve damage and amputations.

Many patients can keep their blood sugar in a healthy range with oral medications and don't need insulin. Unlike insulin, which immediately affects blood sugar and requires regular testing to ensure that blood sugar is in a healthy range, those on oral medication for diabetes don't require regular testing because the pills don't cause rapid shifts in blood sugar, Platt said.

Among the people analyzed who appeared to be needlessly testing blood sugar at home, about 33,000 were taking medications that aren't known to cause dangerously low blood sugar and 19,000 were not taking any diabetes medicines at all.

Half of the patients taking unnecessary blood sugar tests at home took these tests at least twice a day, and half of them had testing supply costs of at least $325 a year, the study said.

The study wasn't a controlled experiment designed to prove whether or how home testing directly affected blood sugar levels in people with diabetes.

And some patients might still need to test at home, even if they don't need to do this multiple times daily, said Sheri Colberg, a professor emerita at Old Dominion University in Norfolk, Virginia, who has studied and treated people with diabetes.

"Even if checking routinely may not change outcomes like overall blood glucose management, the benefit of having glucose testing strips available is that individuals — even non-insulin users — are then able to check their blood glucose when their usual routines vary, during times of illness, or whenever other events may negatively impact their blood glucose," Colberg, who wasn't involved in the study, said by email.

Patients should discuss their home blood sugar testing needs at every checkup, advised Dr. Vanessa Arguello of the David Geffen School of Medicine at the University of California, Los Angeles.

"Diabetic patients who are using insulin or are on oral medications that may cause low blood sugars should monitor their blood sugars multiple times per day including before meals, at bedtime, occasionally after meals to learn about nutrition therapy, prior to critical tasks, and when they suspect low blood sugars," Arguello said by email.

Diabetic patients who are not using insulin or are not taking medications that may cause low blood sugars can monitor their blood sugars less frequently, from twice daily to every other day based on goals established by them and their physician, Arguello added.