Weekend effect: Mortality risk increased if admitted to intensive care units at the weekend compared to weekdays.

A study involving 119 Intensive Care Units (ICUs) in Austria reported a greater risk of death when admitted to the ICU at the weekend compared to a weekday. Alternately, the risk of dying in the ICU on the weekend was lower than on a weekday. This emphasized the complexity of the so-called 'weekend effect.' The study was published in the journal Critical Care.

Lead author of the study Dr. Paul Zajic said: "Our study demonstrates that patients admitted to ICUs at weekends are at increased risk of death. This effect requires thoughtful considerations both by clinicians and policymakers because, in the 21st century, the day of admission should not influence patient outcomes. While one must avoid jumping to conclusions based on retrospective studies, our findings may guide further research, and ultimately lead to systematic improvements that aim to eradicate the 'weekend effect.'"

In the study, researchers collected data on 167,425 patients from 119 ICUs in Austria. The team considered the severity of illness at admission, the reason for admission, the chance of discharge from the ICU to the hospital or home and risk of death following discharge to the hospital, to better understand the factors that might contribute to a weekend effect.

Dr. Zajic described that weekend admissions did not affect patient outcomes immediately but had effects further down the line, and this explained why the death risk in the week was increased compared to the weekend.

The researchers observed that some key interventions in the ICU were less likely to be performed at the weekend, a factor that would not increase mortality immediately. Thus, the mortality risk was raised in the days following a weekend admission caused by systematic issues that lessen optimum provision of care for critically ill patients.

The study found that between weekends and weekdays the severity of illness markedly varied. The severity of illness was increased in patients admitted on the weekend. Another observation on the weekends was of more patients being admitted for 'medical' purposes as opposed to scheduled surgery. Discharge to the hospital from the ICU on the weekend was decreased when compared on a weekday, researchers said.

The study authors stated that the outcomes of this study may not be generalizable to other health systems in other countries and that the observations were limited by their retrospective collection. It, however, provided strong evidence for the presence of the ‘weekend effect’ and described the implications of weekend admission of patients to ICUs.