SAN DIEGO -- A "night float" system designed to restrict the number of hours residents work at night had no significant impact on maternal and fetal outcomes, a study from several Canadian hospitals presented here found.
There was no increased risk of adverse maternal and fetal outcomes in the two years prior to the new schedule compared with the two years after the schedule was instituted (OR 0.97, 95% CI 0.93-1.00, P=0.082), reported Brian Liu, MD, of Sunnybrook Health Sciences Centre in Toronto, and colleagues.
However, the new schedule was linked with a significant 26% increased risk of transfusion and post-partum hemorrhage compared to the earlier system (OR 1.26, 95% CI 1.11-1.44, P=0.0006), and a significant 22% increased incidence of composite surgical and obstetrical complications (OR 1.22, 95% CI 1.08-1.40, P=0.0016).
At a presentation at the , Liu characterized the topic as a "controversial subject."
"The reason they're pushing so much for resident work restrictions is they say that it helps with patient outcomes," he told 鶹ý. "The real question is, is this something we should be pursuing, because the old system seemed to be working fine."
In July 2013, the ob/gyn program at the University of Toronto instituted a night float system, which restricted the number of hours that obstetric residents work overnight for four consecutive nights. Researchers compared all after hours obstetric deliveries (defined as 5 p.m. to 7 a.m.) at three Canadian hospitals. These were comprised of 6,763 deliveries in the "pre-intervention" time period (July 2011-July 2013) to 5,548 deliveries in the "post-intervention" time period (July 2013-2015). Results were adjusted for baseline characteristics.
There was no significant difference in all maternal outcomes, maternal infection, or any fetal outcomes, including fetal mortality or NICU admissions.
Asked for his opinion, Richard Beigi, MD, chief medical officer of Magee-Womens Hospital at UPMC in Pittsburgh said most residency programs that have these restrictions around duty hours "have been around for some time" and most programs have had night floats in place "for many years."
But he added that it was unclear if these "modest findings" were because of the change in schedule.
"There are many other potential causes for these findings, so I am reluctant to say outright they are from the change," Beigi told 鶹ý via email.
Liu agreed that due to the observational nature of the study, they could not say for sure that changes in the residents' schedules caused the difference in outcomes.
But he speculated that increased handover and continued fatigue may have played some role. Liu said that looking forward, hospitals need to examine the clinical, educational, and resident well-being impact of these programs.
Primary Source
American College of Obstetricians and Gynecologists
Liu B, et al "Impact of resident overnight duty hour changes on obstetrical outcomes: A population-based cohort study" ACOG 2017; Abstract 23OP.