"What this variation [in stroke treatment regimens] screams to me is that it is unexplained by the variables that we are able to measure in aggregate across everything," says a neurology researcher.
Every four minutes, someone in the United States dies from a stroke, the fifth-leading cause of death in the United States. About 800,000 people suffer a stroke in varying degrees of severity each year, and it kills nearly 130,000 people, according to the Centers from Disease Control and Prevention.
When the costs of hospital care, medication, rehabilitation and lost productivity are factored in, CDC, estimates that stroke costs about $34 billion a year.
Even with so much at stake, there appear to be wild geographic variations across the nation in how often stroke is treated with the intravenous blood clot dissolving drug tPA (tissue plasminogen activator), a study by University of Michigan researchers in the July issue of Stroke shows.
If, given within a few hours after the stroke, tPA has been shown to restore blood flow to the brain and reduce or prevent damage that can cause long-term disability. Yet, researchers at the UM—examining stroke treatment records of Medicare enrollees from 2007 to 2010 in 3,436 hospital markets across the United States—found that only 4.2% of the more than 844,000 stroke victims received tPA or other urgent stroke treatments.
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James Burke, MD |
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In the bottom one-fifth of the hospital markets patients received no tPA. In the top one-fifth of markets 9% of patients received clot-busting drugs. In Asheville, NC and Stanford, CA as many as 14% of patients received IV tPA or an intra-arterial treatment using tPA or another drugs.
Baffling Variations
There were only minor improvements in treatment levels for patients in regions with certified primary stroke centers, or where emergency medical services drove patients further to get stroke treatment. Older patients, minorities, and women were less likely to get tPA regardless of where they lived, the study showed.
James Burke, MD, senior author of the study and an assistant professor of neurology at UM, says he's hard pressed to explain these disparities in treatment regimens.
"My honest answer is I don't know. It's a whole bunch of different things. My guess is that this is probably a very complicated nut to crack," he says.
Burke says different hospital markets may have differing strengths and weaknesses when it comes to treating stroke.
Variations 'Unexplained' by Variables
"You might have a market with a hospital that is fantastic at delivering tPA, but has a patient population that is only average at identifying stroke symptoms, or you might have fantastic EMS but they are delivering patients to a hospital that is inefficient about identifying tPA candidates and getting people treated quickly," he says. "My guess is it's all of these factors coming together and not any one thing."
"The biggest message is that this is telling us we need to figure out that question," he says. "What this variation screams to me is that it is unexplained by the variables that we are able to measure in aggregate across everything."
The cost of tPA does not appear to be a factor in its limited use, Burke says. A separate study from Michigan State University in 2012 put the per dose cost of tPA at $2,200, but estimated that it provided a "net savings to society of $6,074."
"I don't think the financial barrier is huge because, in part, Medicare amongst others reimburses at higher rates when you treat with this drug," Burke says. "A lot of the drug cost is defrayed by having higher reimbursements rates to incentivize hospitals to use this drug."
He says the "comfort level" of attending clinicians diagnosing stroke is likely a key reason why stroke treatment is so uneven.
"Diagnosing stroke is a tricky enterprise," he says. "There are a handful of very severe strokes that are clear cut diagnostically, but a whole lot of them are less clear cut. Then, you need to have a system in place for all the things that need to happen before you give somebody the drugs. Unless you have a pharmacist ready to reconstitute the drug, a CT scanner ready to go, and physicians and nursing and triage, all those pieces working together, you are going to lose a lot of time and people are going to slide out of time windows."
A Credible Treatment Stroke Regimen
Another problem, he says, is the lingering suspicion in "the emergency medicine community" about the efficacy of tPA, the only Food and Drug Administration-approved drug for ischemic strokes, which account for nearly 90% of all strokes.
"Those sorts of doubts wash out of clinical experience very slowly," Burke says. "I don't think there are a lot of people who would still say, 'I don't use this medicine because it doesn't work,' but it does lead to a reticence about using it. It is one of the factors that needs to improve treatment rates over time."
For community and rural hospitals with limited resources, Burke says, the quickest way to find out if they've got a "credible" stroke treatment regimen is to "determine if you can deliver IV tPA within 60 minutes of someone hitting the door."
"If you have the pieces in place you are probably doing as reasonable a job as you can under the circumstances," Burke says. "If you're a critical access hospital you can ask yourself 'can we provide this service, and if not, what do we need to do to make it happen?' Should we find a hospital to partner with and we can treat them here and ship them there? Do we use telemedicine? Should we pick up the phone, or can we do this all on our own?'"
These pressing questions need to be answered, Burke says, because we can expect to see stroke cases rise over the next decade and beyond as the demographic ages in all parts of the country.
"Stroke is one of the things that should be at the top of the list from an emergency perspective," Burke says. "We have medication that clearly reduces disability by substantial margins, and this is a relatively common diagnosis, and there is clearly substantial room for improvement."
John Commins is the news editor for HealthLeaders.