AARP Hawaii said a new online resource has been launched to help Medicare beneficiaries avoid the "doughnut hole" gap in drug coverage where they are forced to pay the full cost of their prescription drugs for part of the year.

AARP said its new Doughnut Hole Calculator is especially needed in Hawai'i, where a higher percentage of residents enrolled in Medicare fall into the coverage gap than any other state.

AARP, quoting a Kaiser Family Foundation study, said 36 percent, or 33,000 beneficiaries in Hawai'i, went into the doughnut hole in 2007.

That compared with 26 percent nationally. Moreover, AARP Hawaii said the coverage gap is expected to widen in coming years as the cost of prescription drugs escalates.

"Our sense is it's getting more expensive by the year," said AARP Hawaii spokesman Bruce Bottorff.

"Prescription drug costs are outpacing inflation."

The new calculator, available at www.aarp.org/doughnuthole, lets people determine if they will fall into the coverage gap and find ways to avoid it by switching to less expensive medications.

It does so by guiding people through their prescription drug options with localized information about their plans. They will get a graph of their out-of-pocket spending by month and be able to look up lower-cost alternatives.

AARP said there were 193,333 Medicare beneficiaries in the state in 2008 and that nationally the average beneficiary spends almost 30 percent of their income on health care costs.