Physicians can no longer disregard out-of-pocket costs when prescribing medications to their patients, one neurologist and health policy researcher says.

"It's gotten to the point that, even if some don't think it's our role to consider out-of-pocket costs, we're making decisions that impact patients directly," says Brian Callaghan, M.D., M.S., an associate professor of neurology at Michigan Medicine.

Callaghan and colleagues' latest paper on medication pricing found that, as the out-of-pocket price went up for prescriptions for three common neurologic conditions, patients were less likely to take their medication as prescribed.

"These findings should have ramifications for how we practice," Callaghan says. "Gone are the times we could ignore out-of-pocket costs, because they affect whether our patients take the medications we give them."

'Clever' study design

The new study by the American Academy of Neurology, published in Neurology, compared less and more expensive drug options for neuropathy, Parkinson's disease and dementia from privately-insured and Medicare Advantage claims. The drugs they compared are similarly effective and have similar side effects, and the only real difference between them was the price, Callaghan says.

"We focused in on the cost in a clever study design in order to avoid some of the confounding effects in previous studies," says Callaghan, also a member of the University of Michigan's Institute for Healthcare Policy & Innovation. Those confounders could include physician-preferred medications and selection bias.

Callaghan and colleagues analyzed claims from 2001-2016, including more than 55,000 patients with neuropathy, most prescribed gabapentinoids, nearly 20,000 patients with dementia, prescribed cholinesterase inhibitors, and more than 3,000 patients with Parkinson's disease, prescribed dopamine agonists.

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The out-of-pocket cost differences in each medication pair ranged from less than $20 to more than $75 per month, despite the fact that efficacy is known to be similar for all options.

"We found a significant association between price and medication adherence for dementia and one category of neuropathy prescriptions (gabapentinoids), and a positive, though not statistically significant, association between price and adherence for Parkinson's disease and another category of neuropathy prescriptions (mixed serotonin/norepinephrine reuptake inhibitors, known as SNRIs)," Callaghan says.

Other research has also found lower medication adherence with higher-priced drugs in conditions where the drugs are more expensive overall, like multiple sclerosis, he adds. This study shows that even when comparing three conditions that have generally more affordable medications, price still plays a role in adherence, he says.

Rise in neurologic drug costs

Callaghan says many clinicians may not realize that today's medication cost landscape is so drastically different than when they began seeing patients.

"It wasn't that long ago when out-of-pocket costs were so small for medications, and limited to co-pays. Now, we know those costs are going up," he says.

In fact, earlier this year, his team found people with neurological diseases are paying considerably more out-of-pocket for their prescriptions compared to a decade ago. In MS in particular, average patient costs were 20 times higher in 2016 than they were in 2004.Those findings were published in Neurology as well.

Callaghan says it's difficult for physicians to stay updated on all of the changing variables, as pricing depends on many factors including time on the market, whether there's a generic option and the particulars of each patient's insurance plan.

Even when a medication is generic, it can take years to become cheaper, he says, so simply determining which options are generics doesn't always result in lower prices.

Practice implications

To combat this problem, physician and patient education and teamwork are sorely needed, according to Callaghan.

"Physicians need to work with their patients to get them the right medications to increase adherence as much as possible," he says.

What could help? Allowing physicians to easily figure out exactly how much a patient would pay out-of-pocket for a given prescription, ideally right in the medical records system, Callaghan suggests.

That pre-prescription conversation could give the patient an opportunity to say whether they're going to fill and take the medication. If not, other options could be discussed right there, before more treatment time is lost between appointments.

"In order for that to happen, multiple systems would need to work together, including the insurance information and pharmacy information," Callaghan says.

Adherence in other categories of medications

Future research might investigate the association between out-of-pocket cost and adherence for popular extended release formulations, like Keppra XR (levetiracetam) for epilepsy, and combination pills, such as those for blood pressure, Callaghan says.

"These findings make you wonder about the promise of those ideas," he says.

The idea is that medication adherence may be higher if the patient only has to take the pill once or twice a day instead of more often. But could cost trump ease?

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"Extended release formulations usually come with higher out-of-pocket costs, so it's possible the expensive cost is more of a dissuader to a patient than needing to take something multiple times a day," Callaghan says.

And although this wasn't an aim of the study, researchers found overall lower medication adherence rates in minority populations compared to white patients.

"This is consistent with other studies in other diseases about medication adherence," Callaghan notes, so he says physicians should take these disparities into account as well when discussing medication options and medication adherence with their patients.

The first author of the paper is Evan L. Reynolds, Ph.D., from Michigan Medicine. Additional authors are James F. Burke, M.D., M.S., Mousumi Banerjee, Ph.D., Kevin A. Kerber, M.D., M.S., Lesli E. Skolarus, M.D., M.S., from the University of Michigan; Brandon Magliocco, M.P.H., from the American Academy of Neurology; Gregory J. Esper, M.D., MBA, from Emory University.

Paper cited: "Association of out-of-pocket costs on adherence to common neurologic medications", Neurology.