Is there a dangerous 'weekend effect' to hospitals admissions? The verdict is split | CHEST 2026

If you do a simple search on the “weekend effect” in titles and abstracts in PubMed for the past 10 years, you will get 474 results. Researchers have done plenty of studies into whether weekend admission to a hospital is associated with higher mortality rates and other untoward outcomes, such as readmissions. The results are noisy, with some studies showing an association and others not. The 20 meta-analyses don’t settle the issue because results from them are similarly mixed.

An artificial intelligence-assisted search of research abstracts being presented at the CHEST meeting in Phoenix that starts today identified 10 abstracts that focused on the weekend effect, an indication that the weekend effect remains a lively topic. As with the PubMed results, the verdict on whether weekend admission and care is associated with worse outcomes than their weekday counterparts is mixed in the CHEST meeting research, with four of the abstracts summarizing research projects finding that there is a weekend effect, four finding no such effect and two reporting mixed results.

That binary categorizations may obscure some important nuances. For example, a study of the hospitalizations for status asthmaticus, a severe form of asthma exacerbation, found a weekend effect, but the researchers said that one “compelling explanation” for the effect was that patients with status asthmaticus who were admitted on the weekend were sicker.

Here is a summary of the 10 abstracts.

4 studies that found a weekend effect

• ·A retrospective case-control study of 140,425 hospitalizations for status asthmaticus found that weekend admission was associated with increased hospitalization, mechanical ventilation, intensive care unit utilization and cardiac arrest. But these are the results that the authors said could be due to the severity of the illness of the people who are admitted on the weekend rather than any difference in hospital care.
• This study of 228,885 hospitalizations for cardiogenic shock in the 2023, approximately a quarter of which occurred on the weekend, found that weekend admission was associated with a higher crude mortality rate (33.42 vs. 31.59%) and that the association — an 8.2% higher odds of death — was there even after various statistical adjustments. The authors said that reducing the gap should focus on efforts to standardize shock protocols and ensure that there is specialized cardiac critical care available at all times.
• Another study of cardiogenic shock, this one of 12,985 cardiogenic shock hospitalizations found that the weekend patients had higher in-hospital mortality (49.5% vs 42.2%) and 24-hour mortality (26.2% vs 21.6%) than the weekday patients. Utilization of
• A study of patients who underwent pericardiocentesis (4,135 on the weekends and 39,105 on a weekday) on weekends found that those treated on the weekends had a higher risk of all-cause mortality, cardiac arrest, cardiogenic shock and acute kidney injury. The authors said that the absence of differences in postprocedural bleeding and infection suggests that the weekend effect is driven by “systematic vulnerabilities” rather than technical procedural failure.

4 studies that did not find a weekend effect

• A 263,072 study of unweighted hospitalizations for pulmonary embolism, representing approximately 1.3 million weighted admissions, found no weekend effect and, in fact, that weekend admission was associated with a slightly lower risk of in-hospital mortality. They saw the same slightly lower risk in high-risk cases. The authors said modern systems for taking care of patients with pulmonary embolisms “may mitigate historical weekend-related disparities in outcomes.
• A study of 9,075 hospitalizations for bronchial artery embolization, 2,040 of which occurred on the weekend, found that weekend admission was not associated with in-hospital mortality, mechanical ventilation, vasopressor and intensive care unit utilization. The authors said that the results argue for prioritizing timely evaluation and embolization based on the patient’s status “rather than calendar timing.”
• A study of 1,232 adult hospitalizations with hepatocellular carcinoma and acute respiratory failure found that weekend admission was not associated with invasive mechanical ventilation or in-hospital mortality. There was also no difference in the length of stay or charges between patients admitted during the weekend and those admitted on weekdays.
• A study of 449 patients hospitalized for acute exacerbation of chronic obstructive pulmonary disease found no statistically significant difference in readmission rates between those discharged on a weekday and those discharged on the weekend (16.5% vs. 12.1%). The authors note, though, that discharges on Thursday had the lowest readmission rate (4.2%) and those on Sunday, the highest (25.8%).

2 studies in the “other” category

• A study of 2,299 patients with cardiogenic shock with coexisting end-stage renal disease who were treated with intra-aortic balloon pumps found that those admitted on the weekend had a lower in-hospital mortality rate (26.5% vs. 37.1%). In a twist, the authors said looking at best practices during the weekend and applying them broadly may “optimize care delivery through the week.”
• A study of surgical mitral valve repair admissions found no difference in mortality among the 92% admitted during a weekday compared with the 8% admitted on the weekend. This study might reasonably be put in the no-weekend effect category. But the authors noted that weekend admissions were associated with a length of stay that was approximately 11 days longer, although the confidence interval was quite wide on that finding. Significant differences in length of stay and hospital charges highlight opportunities for “targeted quality improvement,” the authors noted.