Maybe these 17 diagnosis possibilities to find out which one is the best? Or maybe the Qualcomm Xprize for the tricorder?
More data needed before wider uptake, researchers suggest
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In an analysis of data from the observational PHANTOM-S study conducted in Germany, 58 out of every 1,000 treated patients will be disability-free, for a number needed to treat (NNT) of about 17, according to May Nour, MD, PhD, of the University of California Los Angeles, and colleagues.
Expanding that to include patients who benefitted to some degree, the number increased to 182 per 1,000, for an NNT of 5.5, they reported at the International Stroke Conference here.
"That's a very significant benefit," Nour told reporters during a briefing. The group did not calculate a number needed to harm, but Nour said it is known from the original paper that there was no "statistically significant difference in harms in terms of symptomatic intracranial hemorrhage or seven-day mortality."
James Grotta, MD, director of the mobile stroke unit at UT Health and Memorial Hermann in Houston, said that if the populations included in the study are the same, "the calculations are probably reasonably accurate. All the data thus far have suggested that moving faster will have a substantial impact on outcome, but we don't know this, and that's why we need to do [randomized] studies."
"It's a reasonable guess based on the data we have," he said. "Is it real? Who knows?"
Grotta's was the first mobile stroke unit program in the United States, launched in February 2014. The first program in the world started in Germany in 2008, under the leadership of Klaus Fassbender, MD. The first data from that program were reported in 2012 in The Lancet Neurology, and showed in a randomized single-center trial that mobile stroke units reduced the time from the initial alert to a therapeutic decision -- but it did not provide any outcomes data.
Last September, another German team led by Alexander Kunz, MD, reported data from the observational PHANTOM-S study in The Lancet Neurology showing no difference in reduced disability whether patients were treated in the mobile stroke unit or with conventional care.
Since outcomes and cost-effectiveness data from large randomized controlled trials are lacking, Grotta's team is in the midst of conducting the largest such trial of mobile stroke units. They've enrolled 280 patients thus far, and have recently signed on mobile stroke teams in Denver and Memphis to contribute to their study.
Their research will also include a cost-effectiveness study, he said.
In the analysis of the PHANTOM-S data -- which included 305 patients treated with tPA in the mobile stroke unit and 353 patients treated conventionally in the ED -- Nour and colleagues also found a greater benefit-per-thousand among those who received the drug compared with those who didn't.
If confirmed in larger controlled trials, she said, these findings suggest that thrombolysis given in mobile stroke units would have a "substantial clinical benefit."
She cautioned, however, that the study was underpowered, and the data were unadjusted.
Nour noted that several other centers in addition to Houston, Memphis, and Denver have mobile stroke units, including the Cleveland Clinic; her own institution, UCLA, has one coming online in the near future.
Grotta said there's "a lot of interest" from centers in mobile stroke units, but "most people, appropriately, are waiting" given the lack of information on outcomes and cost-effectiveness.
There are also challenges with reimbursement, as drugs and procedures cannot be covered if given in ambulances. Some centers have circumvented that challenge by making the mobile stroke unit into an extension of the emergency department, Grotta said.
Some centers simply take a loss of the cost of the drug, said Joseph Broderick, MD, of the University of Cincinnati, who was not involved in either study.
Broderick noted that his institution has not launched a mobile stroke unit partially because of the costs of the initial equipment -- which typically come in at about $1 million -- and partly because of the staffing costs. They were also deterred by limitations on how often and how widely it can be deployed.
"Like with any therapy, we have to see whether it makes a difference in application," he told MedPage Today.
He had praise for the pioneers leading the experiment: "With any new treatment approach, you need to have people who are doing it and getting good at it, to demonstrate effectiveness. You have people who push the envelope."
- Reviewed by Henry A. Solomon, MD, FACP, FACC Clinical Associate Professor, Weill Cornell Medical College and Dorothy Caputo, MA, BSN, RN, Nurse Planner