Outcomes of studies detail benefits of designation.
There are some key components of primary stroke centers that appear to make a big difference. Acute stroke teams reduce time delays and increase treatment by IV tissue plasminogen activator (TPA). Stroke units have repeatedly been shown to improve outcomes, reduce deaths, and reduce complications. Care protocols improve the efficiency of care, improve outcomes, and reduce mistakes.
A meta-analysis of data from 18 well-done, relevant studies showed that stroke unit care was associated with a significant 21% reduction in death and a 13% reduction in the combined end point of death or poor outcome.
A separate 2005 study by Dr. S. Claiborne Johnston and associates of 16,853 patients with acute ischemic stroke at 34 medical centers looked at whether the Brain Attack Coalition’s criteria for stroke centers improved care. Use of an acute stroke team reduced the risk of mortality by 24%. Emergency medical services (EMS) activation of a stroke team reduced mortality risk by 19%. The rate of TPA use at centers that had the most characteristics of primary stroke centers was close to 5% of strokes – double the rate at other centers (Neurology 2005;64:422-7).
Data from the National Institute of Neurological Disorders and Stroke and numerous studies throughout the world show that timely administration of TPA after stroke improves patient outcomes. This is a very important point: If stroke centers did nothing more than increase the use of IV TPA, their effect on patient outcomes would be profound.
A 2006 report from New York State followed 32 hospitals, 14 of which became designated primary stroke centers. They instituted preferential triage, in which ambulances had to bypass non–stroke centers, if possible, to take patients to a stroke center. The rate of TPA utilization nearly doubled. Stroke unit admissions skyrocketed from a little more than 15% to nearly 40%.
In a new study, we looked at TPA use at stroke centers that are certified by the Joint Commission and have gone through either one cycle or three cycles of certification. The rate of IV TPA administration to eligible patients significantly increased in relation to the length of time a hospital had been a stroke center.
The more experienced stroke centers also achieved higher rates of compliance with other care paradigms, including higher rates of discharge on statins and stroke education. These make a difference in preventing subsequent strokes, MIs, and vascular deaths.
A Finnish study included huge numbers of patients – 20,045 at comprehensive stroke centers, 10,749 at primary stroke centers, and 30,891 at general hospitals. Compared with 1-year death rates at general hospitals, rates were 11% lower at primary stroke centers and 16% lower at comprehensive stroke centers. Rates of institutional care were lower at the stroke centers, and the proportions of patients who could go home at 1 year increased by 16% and 22% at the two types of stroke centers, respectively (Stroke 2010;41:1102-7).
A second project in New York State looked at 30,947 patients with acute ischemic stroke in 2005-2006, 15,297 of whom were admitted to a designated primary stroke center. As an internal control group, the study looked at 39,000 patients who were admitted for GI hemorrhage and 40,000 who were admitted for MI to see if these were just better hospitals or if the “stroke center” designation made a difference.
Mortality was significantly lower at primary stroke centers compared with other hospitals at four follow-up time points (0.3% lower within 1 day, 1.3% lower at 7 days, 2.5% lower at 30 days, and 3% lower at 1 year). This is a hard end point. This benefit was consistent in analyses comparing subgroups of hospitals by location or by race or ethnicity (JAMA 2011;305:373-80).
A 2%-3% reduction in deaths from strokes in the United States would mean 16,000-24,000 fewer deaths. There are very few medical interventions that reduce deaths. Trauma centers reduce deaths, and we have molded the stroke center concept after that of the trauma center.
Stroke centers are beneficial for patients and improve outcomes in many ways. They reduce death, and few things do. They improve clinical outcomes and increase the use of TPA. They provide more efficient care and are more effective in starting secondary prevention medications. There are more than 800 hospitals designated as primary stroke centers by the Joint Commission – they can’t all be wrong!
Dr. Alberts is professor of neurology, director of the stroke program, and chief of the division of stroke and cerebrovascular disease at Northwestern University, Chicago. He has received honoraria from Genentech, which makes TPA. Dr. Alberts and Dr. Johnston debated this topic at the American Stroke Association’s International Stroke Conference 2011.
Hospital’s efforts and resources matter, not designation.
I want to remind readers what the question is: Does a “stroke center” designation – not the centers themselves, but the designation – improve patient outcomes?
I want to address three separate questions. First, do some centers provide better stroke care than do others? Second, does care improve at primary stroke centers? Third, does a stroke center designation improve patient outcomes? Most of what Dr. Alberts discussed addresses the first two questions.
I concede the first question completely. There definitely is evidence that care differs among hospitals. Many medical centers had elements of primary stroke centers prior to certification, and some of these elements were associated with better outcomes.
In our 2005 study of 16,853 patients at 34 academic centers in the United States before the start of stroke center designations, several components of stroke centers were already present at different hospitals. Centers that had these components were more likely to give tissue plasminogen activator (TPA). The more components a hospital already had, the more likely they were to give TPA. This says nothing about designation. It just says that those components tend to associate with providing better care. Some of the components also were associated with reduced mortality.
I also concede the second question: Does care improve at primary stroke centers? In studies that looked at care improvements at stroke centers, care got better. Just the fact of looking makes a difference. That occurs in part because of stroke center designation, but how well could we do if we just tracked our own outcomes and we weren’t certified as primary stroke centers? We’d probably do a lot better, compared with baseline, regardless of the designation.
We did a cluster randomized trial of 14 Kaiser hospitals in Northern California and randomized them to an intervention group (standardized discharge orders) or a control group. We took one specific element that’s in all of our stroke centers and worked hard to make that happen in seven hospitals, but not in the other seven.
Even before we started the trial, “optimal treatment” (defined as our combined outcome of blood pressure control, statin use, and anticoagulation if atrial fibrillation was present) improved from 15% to 32% of patients systemwide.
During the trial of 3,360 patients, optimal treatment rates remained statistically stable in the control group (from 32% at baseline to 34% at 6 months) and improved at the intervention hospitals (from 31% at baseline to 38%).
The bottom line is that you don’t need stroke center certification to improve care. Care improves for a variety of reasons. Sometimes other steps are much more cost effective to implement than stroke center certification would be.
The last and only real question in this debate is whether stroke center designation improves patient outcomes. The recently published New York study in JAMA that Dr. Alberts cited showed lower mortality in designated stroke centers than in non–stroke center hospitals, but there are differences between those groups: Stroke centers tended to treat younger patients and those in urban areas, with more teaching hospitals and larger hospitals. The investigators tried to control for those factors, but one thing they could not control for was the fact that hospitals chose to become primary stroke centers. They had the capabilities, and it was feasible at those centers to become primary stroke centers. Already, they were at an advantage.
There is just no solid evidence that the designation improves outcomes for patients. Care differs among hospitals prior to certification. Care improves when you watch it, and was improving well before the certification process began.
Some elements of stroke centers are associated with better care, but certification as a stroke center is not required to pursue those elements. Hospitals that elect to become certified are more likely to provide better stroke care before certification, and are already committed to improving care.
I want to pose a different question: Does society benefit from stroke center certifications? I think the answer is “Yes.” The system of certifying stroke centers provides a framework for regionalization. With stroke center certification, we can convince our EMS teams that they need to bypass the noncertified hospitals and bring stroke patients to hospitals that provide better stroke care. Getting patients to hospitals that provide better care definitely will improve overall care on a societywide level.
Dr. Johnston is professor of neurology and epidemiology and director of the stroke service at the University of California, San Francisco. He said he has no relevant conflicts of interest.