London: In a first that shows cyclic influences on hospital mortality in patients after surgery, a new research says that the risk of death is the highest following surgery conducted on weekends, in the afternoon or in February.
During the analysis of the data from 218,758 patients, researchers found that surgery conducted in the afternoon was associated with 21 percent increased risk of death compared with surgery conducted at other times of the day.
Surgery at the weekend was associated with a 22 percent increased risk of death compared to surgery on weekdays.
February was the highest risk month, with surgery in February associated with a 16 percent increased risk of death compared to surgery in all other months.
Several factors may have influenced this outcome.
"For example, it may be that standard of care differs throughout the day and between weekdays and weekends," said Felix Kork from Charite-University Medicine Berlin, Germany.
"Although we controlled for risk factors including emergency surgery in our study, it may very well be that the patients treated in the afternoon and on the weekends were more severely ill," he explained.
"We need more data to draw conclusions regarding seasonal variation in postoperative outcome," Kork added.
The research was presented at 'Euroanaesthesia 2014' seminar in Sweden May 31-June 3.