The Weekend Effect: Why Giving Birth on Weekends and Holidays is More Dangerous

Welcome to part four of our ‘Hidden Threats’ series, where we summarize some of the latest research regarding medical errors and structural issues that can impact the quality of patient care, both in obstetrics and in medicine generally. Every two weeks, we’ll be providing a short summary of the latest trends, research articles and news that patients may want to know about the way they get their healthcare. Today we’ll be talking about the Weekend Effect.

The Weekend Effect

What Is the Weekend Effect? The Impact of ‘Skeleton Crews’ and Understaffing

During normal business hours, hospitals are fully staffed with cadres of specialists, laboratory staff, surgeons, nurses and other medical staff. Outside of regular working hours, however, it’s a different story. Staff working overnight shifts are vastly reduced, and specialists may be on-call but not within the hospital proper. There are fewer or no administrators, senior managers, and far lower nurse-to-patient ratios. Some diagnostic testing systems and specialized surgical centers may be unavailable. Physician and nursing staff numbers are reduced, which means that in an emergency, there are fewer hands to go around.

All of these factors mean that mistakes due to inadequate supervision, staff handoffs, and other staffing-related issues are more likely. The weekend effect is a name for a trend for poorer patient outcomes (like death or adverse events) due to poorer health care provision during weekends, holidays, and after-hours (when hospitals have fewer staff and resources to draw upon).

Impacts of the Weekend Effect on Patient Safety

Research drawn from routinely-collected health records has confirmed that there is lower-quality care on weekends and after hours, especially for patients that need complex care that is not part of an ER or ICU. Hospital data shows that some patient groups admitted to the hospital via the ER on weekends have higher mortality rates than those same patient groups admitted to the hospital from the ER on weekdays (1,5). These include neonates (newborn babies) and patients with heart conditions. There are also more complications on weekends in US hospitals, especially obstetric trauma (36% increased complication risk) and surgical complications for patients going through vascular procedures (46% increased complication risk) (5).

What Causes the Weekend Effect?

Apart from staffing, there are some other considerations that feed into higher mortality rates outside of regular working hours. One of the key factors is delays in providing urgent treatments. For example, patients with acute heart attacks are less likely to get immediate cardiac procedures if they come to the hospital after-hours. They also have a longer time between when they step in the door and when they have a balloon procedure done (1).  Delayed treatment is associated with a host of factors associated with poorer outcomes:

  • Infection complications
  • Longer length of stay
  • Increased mortality risk

Further, this effect is not related only to patients admitted to the ER – poorer outcomes on weekends were reported for populations including:

  • People going in for elective surgeries
  • Patients having a heart attack while in the hospital
  • Adults admitted to and discharged from intensive care

Weekends Carry Increased Mortality Risk

Research of huge data sets (nearly 15 million hospital admissions) show that being admitted to the hospital on a weekend (as opposed to a weekday) increases the risk of death at 30 days by 15% (2). The reasons for this are hotly debated. Some researchers believe this is a matter of understaffing – overextended staffers make more mistakes when they must attend to a greater number of people. The solution to this is simple – greater staffing during off-hours, including overnight and weekends. If the problem is related to hospital policy that results in delayed treatments, then the solution is rewarding good off-hours work.  One proposal is to abandon the regular-hour/off-hour model and instead institute a 24/7 shift pattern, but hospital management policies are slow to adopt such a model, as it would increase costs significantly.

The Weekend Effect in Obstetrics and Gynecology

One recent study found that the weekend effect was real and significant for women admitted  for labor and babies born on the weekend (3,4). On weekdays, the perinatal mortality rate was 6.4 per 1000 babies, while on weekends, it was 7.3 per 1000 babies. Furthermore, babies born on weekends had an increased risk of being stillborn or dying in the hospital within 7 days. The study also suggested that there were also higher rates of other complications, including:

  • Infections of the reproductive tract
  • Injury to the baby
  • Emergency 3-day readmissions of the baby to the NICU.

Complex Care Impacted By Lower Staffing

One study that looked at complications rates related to vascular surgery (a complex and delicate operation) are higher, signaling that surgeries that require specialization are more sensitive to weekend working conditions (ie understaffing and fewer resources (5)). The study also suggests that complications in urgent, high-risk C-section cases is related to staffing and skill levels, which may be lower on the weekend.

Studies Likely Underestimate the Weekend Effect

The study also noted that it was likely that inequalities of care between weekends and weekdays were more significant than the study itself indicated, as this research only looked at eight different complications out of possible dozens. The modest effects this research found may potentially be much larger when taken in the context of all the possible complications that can occur daily in hospitals.


  • Gallego et al. Insights into temporal patterns of hospital patient safety from routinely collected electronic data. *Health Information Science and Systems 2015, 3(Suppl 1):S2 content/3/S1/S2
  • Rahul Potluri et al.  Is it time to re-appraise the weekend effect? Journal of the Royal Society of Medicine; 2015, Vol. 108(10) 382–383
  • William L Palmer et al. Association between day of delivery and obstetric outcomes: observational study. BMJ 2015;351:h5774. doi: 10.1136/bmj.h5774
  • Jonathan M Snowden et al. Is there a weekend effect in obstetrics? BMJ 2015;351: h6192 doi: 10.1136/bmj.h6192
  • Eran Bendavid et al.  Complication Rates on Weekends and Weekdays in US Hospitals. The American Journal of Medicine (2007) 120, 422-428.