U.S. seniors forced to pay full price for their medications while in Medicare's so-called donut hole didn't suffer more heart attacks or deaths as a result, in a new study.

During several months spent in the Medicare coverage gap, when the government-run insurance program's Part D component stops covering medications, seniors were no more likely than peers with drug coverage to be hospitalized for, or die from, a heart-related problem.

After a small deductible, Part D drug plans typically cover 75 percent of drug costs up to a certain dollar figure, which was $2,400 in 2007. After a beneficiary reaches that level, there is no coverage until the person has spent potentially thousands of dollars out of pocket, then coverage kicks back in.

That gap, also known as the donut hole, will eventually be closed by the Affordable Care Act in the year 2020. But until then, patients still face increased drug costs.

"When prices go up, people tend to reduce their consumption of non-essential and essential medications," said Jennifer Polinski, the study's lead author and an instructor at the Harvard Medical School and Brigham and Women's Hospital in Boston.

There's also evidence that poor adherence to medications affects rates of illness and death, she added.

The fear, Polinski told Reuters Health, is that seniors are more vulnerable when they stop taking their medications because of higher drug prices.

To see whether being in the donut hole translated into a higher risk of death or illness from heart-related events, Polinski and her colleagues looked at about 19,000 seniors in Medicare Part D between 2006 and 2007.

The team compared an equal number of seniors who had low-income subsidies to cover drug costs in the donut hole and seniors who were getting no help paying for drugs during the coverage gap.

Of the 9,383 people who received some help paying for their drugs while in the gap, 122 died.

Among 9,383 seniors who had no extra financial support during the coverage gap, 135 died, according to findings published in the Journal of the American Geriatrics Society.

The difference, according to the authors, is not statistically significant, meaning it's so small it could have been due to chance.

The same was true of hospitalization rates for various heart problems, such as heart attack, stroke or heart failure, among the two groups.

Although these results seem positive, the researchers caution that they only looked at the short span of time seniors spent in the coverage gap, which was about three months during this particular study.

They can't say whether more seniors without financial help died or were hospitalized after their coverage started again at the beginning of the next calendar year, but possibly as a result of having gone without their meds for an extended time.

Despite the study's findings, Polinski said patients should talk to their doctors if they're have trouble paying for medications, because doctors may be able to prescribe a generic version instead.

"I think it's still something patients need to be concerned about until the gap is closed," Polinski said.

The study is published in Journal of the American Geriatrics Society.