As out-of-pocket costs go up for drugs for the Alzheimer's disease, peripheral neuropathy and Parkinson's disease, people are less likely to take the drugs as often as their doctors prescribed, according to a study this week in Neurology.
"These results are concerning, especially as we've seen the cost of prescription drugs continue to rise and an increasing amount of the cost being shifted to patients through out-of-pocket costs," said study author Brian C. Callaghan, MD, MS, of the University of Michigan in Ann Arbor.
The study found that increases in out-of-pocket costs by $50 were associated with lower adherence. For Alzheimer's disease, a $50 increase in out-of-pocket costs was associated with a 12% decrease in the medication-possession ratio. For peripheral neuropathy, a $50 increase in out-of-pocket costs for the gabapentinoid drugs was associated with a 9% decrease in the medication possession ratio.
The study was supported by the American Academy of Neurology.
Callaghan also noted that people with Alzheimer's disease and neuropathy often have other conditions that require medication, so the effect of out-of-pocket drug costs may be magnified.
"Out-of-pocket costs have risen to the point where systematic changes are needed," said James C. Stevens, MD, FAAN, President of the American Academy of Neurology. The academy is advocating for a cap on out-of-pocket costs in Washington, Stevens said.