Dementia patients who get prescriptions from multiple health systems may face a higher risk of drug mix-ups or unsafe interactions than people with cognitive problems who get all their medications from one place, a study of U.S. veterans suggests.
Researchers examined data on more than 75,000 veterans with dementia and found that among patients who received all of their care at Department of Veterans Affairs (VA) facilities, 39 percent had potential safety issues with prescribed medications.
Among those who got some care at the VA and some treatment elsewhere, however, 59 percent had possible drug safety issues, the study found.
"Generally speaking, older adults are at greater risk of having adverse drug events," said lead study author Joshua Thorpe, a researcher at the VA Pittsburgh Healthcare System. "These risks are exacerbated in persons with dementia."
The average dementia patient has four other chronic health conditions and receives care from five different providers in a typical year, researchers note in the Annals of Internal Medicine.
All of these medical conditions come with prescriptions - at least five different drugs for a typical dementia patient and up to nine or more different medicines for 16 percent of these patients, the authors write.
Federal policy shifts over the past decade have made it easier for elderly veterans to access care outside the VA and get prescriptions from doctors working for other health systems. Most recently, the Veterans Access, Choice and Accountability Act expanded access to non-VA facilities to veterans who couldn't get seen within 30 days or who lived more than 40 miles from the nearest VA providers.
To see how expanded access to care outside the VA might influence medication safety for veterans with dementia, researchers studied patients who qualified for care through the VA as well as through the Medicare Part D drug benefit.
Overall, 44 percent of the patients in the study had prescriptions that carried risks for dementia patients, either when taken alone or when used in combination with other drugs patients got at the same time.
Veterans using the VA as well as other health systems had more than double the risk of being exposed to powerful "anticholinergic" medications - drugs that make dementia drugs less effective and increase the risk of memory problems, dizziness and falls.
Dementia patients with prescriptions from inside and outside the VA system were also more likely to receive antipsychotics, which are known to increase mortality in people with dementia.
One limitation of the study is that researchers lacked data on over-the-counter medications, which can also pose safety issues when taken by dementia patients or mixed with other drugs.
Still, the authors suggest a policy fix - implementing electronic health information exchanges and medication therapy management services that can connect data from the VA to other health systems.
The study highlights one way that efforts to increase access and choice may boost the risk of unintended drug safety issues, Dr. David Gifford, a researcher at Brown University in Providence, Rhode Island, writes in an accompanying editorial.
"We have known for a while that making sure we know the medications a person is currently taking compared to what they used to be taking when they transition between providers such as being discharged from a hospital to the community is an important task to prevent medication related errors," Gifford said by email.
"We also have known that the lack of information on a person's medication and allergies at the time of being prescribed new medications can increase the risk of receiving medications that may cause an adverse event or interact with other medications," Gifford added.
The best thing patients and families can do is carry a list of every prescription and over-the-counter medication or supplement they take - and show it to every new provider or pharmacist they see, Gifford said.