The “weekend effect” is real for cardiology admissions, according to a study that found worse mortality outcomes for patients with acute myocardial infarction admitted to a major tertiary hospital on a Saturday or Sunday.
Mortality rates were up to 80% higher for patients admitted on the weekend as compared to Monday to Friday admissions, a study conducted over a six year period at John Hunter Hospital, Newcastle, NSW.
The retrospective study investigated mortality outcomes for more than 14,000 patients admitted by a cardiologist from 2012 to 2017, with a comparison of rates for weekday (n=8,951) and weekend (n=2,098) admissions.
In-hospital mortality for weekend admissions were significantly higher compared to weekday admissions (adjusted Odds Ratio 1.78).
Rates were also higher for 30-day mortality in weekend admissions (OR 1.74) and at one year ( OR 1.33).
Adjusted for diagnosis, there was a significant increase in in-hospital, 30-day and one-year mortality seen only for weekend admissions with the final diagnosis of acute myocardial infarction. There was no difference in mortality between weekday or weekend admissions in patients with a discharge diagnosis of heart failure, arrhythmia or chest pain unspecified.
The weekend effect was also observed with out-of-hours admissions, and there was a change in hospital work patterns, with lower rates of admission and decreased discharges from hospital.
The study authors, led by Dr Michael McGee, said the weekend effect was a well-studied phenomena and had previously been observed across a range of diagnoses including acute MI, stroke, hip fracture, COPD and pulmonary embolism.
It was presumed due to reduced access and longer waiting times for services such as diagnostic testing and interventional procedures such as reperfusion. In the current study a weekend admission was also associated with a longer hospital length of stay (78 hours vs 64 hours) than weekday admissions, the authors noted.
However the differences might also relate to different patient characteristics, they said, noting that the proportion of patients transferred from smaller hospitals was higher on weekdays.
In their paper, they said that the weekend differences seen in mortality for acute MI did not appear to be explained by differences in PCI access at the hospitals, which has a 24/7 catheterisation lab, and no difference in door-to-balloon time for weekday versus weekend patients.
It had been suggested that the weekend effect may reflect selection bias, with patients with less severe symptoms presenting on the next working day as opposed to a weekend, they added.
“Weekends are difficult times to manage acutely unwell patients. This study showed that mortality was higher on weekends especially for sick patients transferred from regional centres to a tertiary care site,” Dr McGee told the limbic.
He said any steps to reduce the weekend effect need to move to a system where weekend practices are not substantially different to a usual business day. The question of whether changes in organisation practice and the increased costs incurred would reduce mortality in this high-risk group needs to be addressed by further directed research.
“The study shows the importance of improving systems of care especially during times when hospital resources are necessarily limited. There is a tension between providing optimal care for sick patients who arrive at all hours and looking after the health of the staff who care for them – finding the right balance is challenging.”
The findings are published in Heart Lung and Circulation.