Deaths Higher for Strokes Treated at Night, on Weekends

Susan Jeffrey
Two new studies again suggest that stroke mortality is higher in patients who are admitted to the hospital during nights and on weekends.
The results were presented here during the International Stroke Conference 2008.
In 1 report, researchers led by Matthew J. Reeves, PhD, associate professor of neurology at Michigan State University, in East Lansing, researchers found that the risk for in-hospital mortality was higher for all patients who presented after hours and on weekends, but particularly so for hemorrhagic stroke patients.
The other study, with lead author David S. Liebeskind, MD, associate professor of neurology at the University of California, Los Angeles, showed that mortality was higher for patients with any stroke admitted to the hospital on a weekend vs a weekday.
The findings, both researchers speculated, may reflect differences in the quality of care offered to stroke patients during these off-hours.
"There are differences here that shouldn't be," Dr. Liebeskind told reporters here. These findings "set the course for items to address to make sure that these inequalities are not persisting."
Dr. Reeves pointed out that roughly half of stroke patients in his study were treated during off-hours. Based on this, they calculated the population-attributable risk of this differential between on- and off-hours. "It's about 5%, so theoretically, if you could get rid of the difference between on-hours and off-hours, you could lower the mortality rate by 5%," Dr. Reeves said. "Probably there are not many things you'll see at this conference this week that could do that."
Weekend Presentation a Hazard
Previous studies in Canada and Europe have suggested that patients admitted for stroke on the weekends have poorer care and higher risk-adjusted mortality, Dr. Liebeskind said. In the study presented here, the researchers looked at stroke outcomes in the United States, comparing weekend and weekday admissions.
They used data on more than 2.4 million stroke admissions from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project between 1988 and 2004 based on International Statistical Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes 430 to 438. Annual percentages and trends analyses were conducted for demographic variables, admission characteristics, procedures, and outcomes. Of 2,409,043 total admissions, 1,397,883 were ischemic strokes.
Patients admitted on weekends vs weekdays did not differ in age, race, sex, or socioeconomic status, they note. Weekend patients were more often admitted emergently (70.2% vs 53.5%), but length of stay was similar between cohorts.
The researchers found that the mortality rate for all stroke patients admitted on weekdays was "remarkably lower," they write, than weekend admissions, a pattern that was also seen in the ischemic stroke subgroup.
Patients were also more likely to be routinely discharged if they were admitted on weekdays compared with weekends (53.2% vs 43.8%; P < .001). Again, this was also true of the ischemic stroke subgroup.
Dr. Liebeskind noted that the cohorts had a similar number of procedures done, but those in the weekend cohort underwent their first procedure almost 1 day later than the weekday group, with the first procedure at 2.65 days after the event, vs 1.76 days for the weekday group.
He added that although stroke mortality did go down during the 15-year period, the differential in mortality between those admitted on the weekend vs weekdays persisted.
Their analysis ended in 2004, during a time when primary stroke centers were still being developed and mobilized throughout the country, he added. "We don't know how things will sit in coming years with stroke centers that have been developed and tailored, so that remains to be seen, but the hope is that we standardize care irrespective of the day of the week."
Increased Risk with "Off-Hour" Admissions
In a separate report, Dr. Reeves and colleagues looked at outcomes among 308,545 stroke admissions at 857 US hospitals participating in the Get With the Guidelines — Stroke (GWTG-Stroke) program, a continuous quality-improvement program through the American Heart Association/American Stroke Association (ASA). They included hospitals that submitted at least 20 cases between October 2001 and April 2007.
For this analysis, 883 cases were excluded because they did not arrive at the emergency department, and 6701 cases that did not have data on mortality status were also excluded. A total of 187,669 ischemic stroke and 34,845 hemorrhagic stroke cases were included in the final analysis.
"On-hour" presentation was defined as presentation between 7 AM and 6 PM on weekdays, and "off-hour" presentation as presentation at any other time. The relationship between time of presentation and in-hospital mortality was examined using generalized estimating equation methods, adjusted for a variety of patient and hospital variables.
They found 50% of ischemic stroke cases and 57% of hemorrhagic stroke cases presented during off-hours. In-hospital mortality was higher for both ischemic and hemorrhagic stroke cases who presented during off-hours.
After adjustment for demographic factors, stroke risk factors, arrival mode, and hospital characteristics, presentation during off-hours was still associated with a small but statistically significant increase in the risk for in-hospital mortality for both stroke types.
They did see a trend to some improvement during the study period, suggesting an effect of the GWTG-Stroke quality-improvement program, he noted. "We did see a narrowing of the difference between off-hour higher mortality and longer program participation. It's observational data, and I'm not saying that's causal, but there is a trend."
However, he noted, "You'd think that if you participate in a quality-improvement program there would be some spillover; that you wouldn't just see improvement from Monday to Friday, but you would see improvement on weekends as well," he said. But he said, "We really don't know the mechanisms of this and really need better data to say exactly what's causing it."
More precise measures, for instance, such as the delay in imaging seen in Dr. Liebeskind's data, would be helpful in pinpointing the problems, he added.
"I think it's a public health issue about why we find this acceptable, that hospitals can provide basically a different business model on the weekends," Dr. Reeves said.
Dr. Liebeskind agreed. "Instead of looking for a magical therapy, fix the weekend problem."
Room for Improvement
In a statement from the ASA, advisory chair Ralph Sacco, MD, from the University of Miami, in Coral Gables, Florida, said, "Although we are improving our rapid treatment approaches for acute stroke and improving outcomes, these new studies suggest that we may have room for improvement for those cases who present during off-hours. The outcome disparities, however, were greatest for hemorrhagic stroke patients, for whom we have the least successful treatments to offer."
Dr. Liebeskind has disclosed that he has received funding from the National Institute of Neurological Disorders and Stroke. Dr. Reeves has disclosed no relevant financial relationships.
International Stroke Conference: Abstracts P174, P540. Presented February 20, 2008 and February 21, 2008.