A quarter of patients with diabetes surveyed at a Connecticut health center reported under-using insulin because of its cost.

The survey, conducted by Yale School of Medicine Researchers, included 199 people treated for type 1 or type 2 diabetes at the Yale Diabetes Center between June and August 2017. The results were published Tuesday in JAMA Internal Medicine.

The survey’s small sample size and limited geographic scope means it may not represent the broader public, but researchers say their findings about how drug costs influence behavior are noteworthy.

“These results highlight an urgent need to address affordability of insulin,” the authors wrote. “Insulin is a life-saving, essential medicine, and most patients cannot act as price-sensitive buyers.”

The cost of insulin tripled between 2002 and 2013, and has increased by 64 percent since 2014, according to GoodRx, a website and mobile application that tracks drug prices. GoodRx analyzed prices for 22 insulins and found that prices are rising for all types -- short-, immediate-, rapid-, and long-acting -- but vary by type and brand.

In the Yale survey, respondents reported a range of cost-related issues, such as taking smaller doses than prescribed, stopping use of insulin and not filling a prescription.

A third of respondents said they did not discuss their financial concerns with their doctor.

In the Philadelphia area, some patients have found creative ways to get the medications they need without breaking the bank, such as traveling abroad or ordering medication from international online pharmacies.

Some doctors even suggest a trip to Europe to stock up on medication.

Doctors are often unaware of the cost of medications they recommend, but Yale researchers suggested that asking patients about their ability to pay could make a difference in whether they follow their recommended treatment.