American College Of Surgeons - Inspiring Quality: Highest Standards, Better Outcomes

Featured Commentary

The online formats of SRGS include access to What You Should Know (WYSK): commentaries on articles published recently in top medical journals. These commentaries, written by practicing surgeons and other medical experts, focus on the strengths and weaknesses of the research, as well as on the articles' contributions in advancing the field of surgery.

Below is a sample of one of the commentaries published in the current edition of WYSK.

Walker AS, Mason A, Quan TP, et al. Mortality risks associated with emergency admissions during weekends and public holidays: an analysis of electronic health records. Lancet. 2017;390(10089):62–72. Free Full Text

Commentary by: Eileen M. Bulger, MD, FACS

Several studies have sought to address whether or not the outcome in hospitals is affected by after-hours care. This is an important issue, as our hospitals should provide the highest quality care 24 hours a day, seven days a week; if we are missing that mark, then these issues should be identified as a focus for quality improvement. The weekend effect is an example of this, and several studies have proposed that patients admitted on weekend days have a higher mortality than those admitted on weekdays. This finding has been attributed to differences in staffing and resource availability on the weekends that may impact patient care. However, it is important to account for potential differences in the types of patients and the severity of illness in those admitted on the weekends. The authors of this study sought to address this issue by utilizing electronic health records of emergency admissions from four hospitals in the National Health Service in the United Kingdom over a nine-year period. These records include detailed clinical laboratory data that was used to help account for variations in illness severity. The primary outcome was 30-day mortality.

Similar to previous studies, these authors also noted an increase in the unadjusted mortality for patient admitted on the weekends, eight to nine percent higher; however, after adjusting for differences in the test results, there was no significant difference in mortality rate. Differences in biochemical and hematological studies accounted for 33 percent of the excess mortality on Saturdays and 52 percent of the excess mortality on Sundays. The only subgroup that continued to demonstrate increased mortality after adjustment were those admitted between 11 a.m. and 3 p.m. on weekends. Adjusted analysis of admissions on public holidays showed similar results. In addition, these authors evaluated measures of hospital workload, including hospital occupancy, and did not find any association with increased hospital workload and 30-day mortality—although data on staffing levels were not available.

The question for surgeons is how does this apply to the management of surgical emergencies. A recent study utilizing data from the University HealthSystem Consortium, between 2009 and 2013, studied the weekend effect for the seven most commonly performed emergent general surgical procedures: appendectomy, cholecystectomy, laparotomy, lysis of adhesions, partial colectomy, peptic ulcer disease repair and small bowel resection.1 In this study, four of the seven procedures demonstrated higher mortality on the weekends for both adjusted and unadjusted analyses; these included laparotomy, lysis of adhesions, partial colectomy, and small bowel resection. While the authors adjusted for severity of illness, this effort was limited by the variables available in this administrative dataset, and the authors were not able to capture acute decompensation of a patient that may have prompted a weekend operation. The authors did not have access to differences in laboratory data as was included in the paper above.

In addition, studies of patients admitted for traumatic injury in both the United Kingdom and in the United States have failed to demonstrate any evidence of a weekend effect on mortality.2,3 This suggests that the investments that have been made in designing organized trauma systems to manage a high volume of night and weekend emergencies may overcome any staffing or resource limitations that could potentially impact emergency care at non-trauma centers. This may lend additional support for regionalization of complex emergency surgical care to hospitals that support a 24/7 acute care surgery model.

In summary, while the weekend effect has been described in many settings using administrative data, this paper highlights the need to adjust for both patient level factors and illness severity before concluding that the problem will be solved simply by increasing staffing or resources. By successfully addressing this issue, trauma systems may also offer potential solutions, particularly for patients requiring complex emergency general surgery.


  1. Hoehn RS, Go DE, Dhar VK, et al. Understanding the “Weekend Effect” for Emergency General Surgery. J Gastrointest Surg. 2017;2:1-8. doi:10.1007/s11605-017-3592-x.
  2. Carr BG, Jenkins P, Branas CC, et al. Does the trauma system protect against the weekend effect? J Trauma. 2010;69(5):1042–7–discussion1047–8. doi:10.1097/TA.0b013e3181f6f958.
  3. Giannoudis V, Panteli M, Giannoudis PV. Management of polytrauma patients in the UK: Is there a 'weekend effect'? Injury. 2016;47(11):2385-2390. doi:10.1016/j.injury.2016.10.007.