A children’s hospital with no rapid response team showed the same reductions in mortality during the same time frames as did hospitals that attributed their drops in mortality to their rapid response teams, according to a report in the May issue of the Archives of Pediatrics and Adolescent Medicine.
The "before-and-after" design of studies that purport to show the benefits of rapid response teams are inherently flawed. The fact that their own such before-and-after study reached the same conclusion at a hospital with no rapid response team shows that evidence supporting such teams is open to question, said Dr. Ari R. Joffe of the University of Alberta and Stollery Children’s Hospital, Edmonton, and his associates.
Pediatric rapid response teams, also known as medical emergency or critical care outreach teams, are groups of experts always ready to intervene when a cardiopulmonary arrest seems imminent and to respond to when one occurs. They have been touted as a means to reduce mortality from in-hospital cardiopulmonary arrest.
But the only studies that support this contention have relied on "before-and-after" designs in which present-day cohorts were compared with historical controls who were treated before the rapid response teams were implemented. This design fails to account for many variables known to affect mortality, such as temporal trends, differences in case mix, and differences in severity of illness.
To test the hypothesis that favorable study results actually were due to flaws in study design, Dr. Joffe and his colleagues reviewed mortality patterns at their own hospital, which has no rapid response team, during the same before-and-after periods.
They found a highly significant reduction in mortality at their hospital during the same intervals in which two studies found similar reductions and attributed them to their rapid response teams.
Moreover, Dr. Joffe and his associates found no reduction in mortality at their hospital during other intervals in which three other studies found no such reductions.
In addition, "when we divided our data into equal 4- and 5-year periods, there was a highly significant reduction in hospital mortality in the ‘after’ periods compared with the ‘before’ periods at our hospital."
And the results were the same in a year-by-year logistic regression analysis of the data at their hospital.
"If we had implemented a [rapid response team], we would likely have misattributed the reduction in hospital mortality over time to this intervention," the researchers said.
"These results call into question the strength of the pediatric medical emergency team data from the cohort studies with historical controls," they noted (Arch. Ped. Adolesc. Med. 2011;165:419-23).
The studies that purport to show the benefits of rapid response teams also were flawed in other ways. For example, hospitals each used different criteria for calling the rapid response team, and the rates of making such calls varied markedly between hospitals, but such differences were not accounted for in analyses of the data.
No financial conflicts of interest were reported in Dr. Joffe’s report.