People with diabetes who are enrolled in the US federal Medicare health programme are two to three times more likely to use "expensive" brand-name drugs than diabetes patients who are treated within the Veterans Administration (VA) Healthcare System, new research shows.

Spending on Medicare's prescription drug benefit, known as Part D, would have been an estimated $1.4 billion less in 2008 if its brand-name and generic drug use had matched that of the VA for the medications studied, according to the researchers, from the University of Pittsburgh, VA Pittsburgh Healthcare System and Dartmouth College. Their report, the first large-scale comparison of prescription drug use between Medicare Part D and the VA, will be published in the Annals of Internal Medicine this week.

"Our study shows that we can make a big dent in Medicare spending simply by changing the kinds of medications people are using - and physicians are prescribing - without worrying about whether the government should or should not negotiate drug prices," commented lead author Walid Gellad, an assistant professor in the Pitt Graduate School of Public Health's Department of Health Policy and Management and Pitt's School of Medicine.

'The levels of generic use found in the VA are attainable, and they are compatible with high-quality care," he added.

Medicare and the VA have a significantly different approach to drug prescribing, the authors note. Medicare contracts with more than 1,000 private insurance companies, each using a distinct formulary and cost-sharing arrangement for prescribing drugs, while the VA uses a single formulary and all veterans have the same cost-sharing arrangement.

Of the four medication groups commonly used by patients with diabetes, the researchers found that Medicare beneficiaries were more than twice as likely as VA patients to use brand-name drugs in almost every region of the country.

"We're not suggesting that Medicare turn into a VA system, nor do we believe that brand-name drugs have no role in improving health. This study is about how we can manage our limited resources while maintaining high-quality care. The VA shows it can be done for prescription drugs," said Dr Gellad.

Meantime, the US Senate Special Committee on Aging's two leading members have asked the Government Accountability Office (GAO) to investigate the pricing and coverage details provided by Medicare Part D plan sponsors on the programme's online prescription drug Plan Finder, and also to look at how well the government is doing in ensuring that the companies are adhering to Medicare marketing guidelines.

The request, from Committee chairman Democrat Bill Nelson and ranking member Republican Susan Collins, has been spurred in part by official findings that aggressive marketing tactics used by Medicare Advantage plans may be misleading consumers about the true cost and scope of benefits. Around 38% of all Medicare beneficiaries are enrolled in a Medicare Advantage plan that includes drug coverage, but for the remaining 62% enrolled in stand-alone Medicare drug plans, no such investigation has been undertaken to examine the accuracy and oversight of online marketing information on which these seniors rely to select their coverage, say the Senators, in their request to the GAO.

"With more than $65 billion invested, and important personal coverage decisions at stake, ensuring plan sponsor compliance with fair market practices to senior and the accuracy of the information provided to beneficiaries electronically is essential for both beneficiaries and the taxpayer," they write.

They also point to official warnings that the Medicare Part D programme is "particularly vulnerable to fraud and abuse."