People who work in health care will tell you that it is best not to have an acute illness, give birth, or require intensive care over the weekend, on holidays, or even during the night. Staffing is often not as good during those times, and the evening shift providers tend to wait until the day shift people arrive before decisions are made. On holidays in teaching hospitals, the attending physicians are often home with their families and the residents have to make treatment decisions themselves or risk the ire of the attending when he or she is called on Christmas day or during their New Years party. And, of course, there is the well-known “July” effect, when the new residents come to an institution on July 1 and suddenly have very sick patients under their care when they barely know how to find their way around the hospital.

There has been little empirical research on this notion, however, at least not until recently when the British Medical Journal published a study that found that the rate of complications in obstetrics, for both babies and their mothers, increased over weekends. The study examined the records of over one million obstetrical patients over a two-year period. The measures of quality and safety of maternal care showed a negative association with deliveries that occurred over the weekend.

The conclusions matched some earlier research in the United States that studied almost one million elderly patients who were hospitalized over the weekend for heart attacks, finding that the one-year mortality rate was elevated for the weekend patients. Another study in Canada found that weekend patients who presented with abdominal aneurysms, acute epiglottitis, and pulmonary emboli had significantly higher in-hospital mortality rates than those admitted during the week.

The reasons may, as noted earlier, be based on staffing levels. In many hospitals, the ratio of hospitalists to patients during the night shift is much lower. This may lead to night hospitalists only seeing a patient if a nurse brings some problem to their attention, as opposed to making rounds on the patients themselves. It can also result in a hospitalist near the end of a night shift deciding to wait until the day-shift doctor comes on board before making key diagnostic or treatment decisions. Human nature being what it is, the more experienced providers may use their seniority to choose to work during the day rather than at night or over weekends. If you suffer an acute medical problem at 2:00 a.m., it is less likely you will get the prompt attention of the senior specialist at the facility. Rather, it is more likely the providers will try to keep you alive until the specialist arrives hours later. If the same acute problems arise at 11:00 a.m., the delay before being seen by the specialist may be much less.