Bad Blood? Challenging Superstitions in Medicine

Galveston, Texas is a picturesque city located on an island in the Gulf of Mexico. The sandy beaches and warm waters have long attracted visitors, and the population of the city swells every summer with approximately forty thousand additional souls at any given time. Events and festivals draw in even more, with upwards of one hundred thousand visitors over the course of a weekend.

Of course, more people on the island means more traffic in the local emergency departments, including more trauma activations, more admissions, and the utilization of more resources like blood products. The people working in healthcare are aware of this, with superstitious trepidation assigned to one event in particular – the Lonestar Biker Rally, locally known as Biker Weekend.

Occurring every October, the Biker Weekend brings an estimated one hundred thousand motorcycle enthusiasts to Galveston for four days of festivities. Recent years have featured high-profile, fatal, motorcycle accidents and even shootings, making Biker Weekend one of the most feared calls for local healthcare workers. Out of this fear comes rumors – that Biker Weekend has the highest rate of mortality in the hospital, that Biker Weekend features the most trauma codes, and that Biker Weekend uses the most blood products of any weekend in the year.

While I can’t address all these superstitions, together with my colleagues Dr. Sri Bharathi Kavuri, Dr. John Broussard, and Ms. Ashlie Atchison, I looked into whether Biker Weekend does indeed use an abnormally high number of blood products.

The first step was to choose an appropriate control for our hypothesis that would address confounding variables. While the activities during Biker Weekend, with their mix of motorcycles, alcohol, and sometimes violence, certainly appear to have more potential for danger, trauma, and blood usage, we would need to control for the effect of increased population. To do this, we would need to select a comparison event with a similar population increase but without the same potential hazards, and eventually chose Memorial Day Weekend as an appropriate comparison.

Next, we pulled the total number of each blood product type dispensed over either Memorial Day Weekend or Biker Weekend over the past five years, from 2018 to 2023. In 2020 no Lonestar Biker Rally was held due to concerns over the pandemic, so for both events the year 2020 was omitted. Finally, we pulled the total number of Massive Transfusion Protocols, or MTPs, which are defined as the transfusion of 10 or more packed red blood cells. MTPs are typically seen in cases of massive hemorrhage such as a traumatic accident.

Comparing the type and total blood products dispensed over the two weekends from 2018 to 2023 (and omitting the year 2020), we see no statistically significant difference. This includes packed red blood cells (RBC), fresh frozen plasma (FFP), platelets, and cryo. There is a trend towards transfusion of greater numbers of FFP units during Biker Weekend (P=0.11), but more data would be needed to properly assess this.

We did find a trend towards a higher number of MTPs on Biker Weekend, although the difference was not quite statistically significant from this data set (P=0.078).

Tracking the number of MTPs for the past 5 years indicates that MTPs during Biker Weekend are increasing over time. However, tracking the number of MTPs during both events for the next several years will be needed to firmly determine whether there is indeed a higher number of MTPs on Biker Weekend.

We cannot conclude that Biker Weekend involves the utilization of more blood products. The data suggest the opposite – that Biker Weekend uses the same total blood products as other very populous events on Galveston Island.

However, how blood products are dispensed from the blood bank may very well be different. With more data over time, we may see that Biker Weekend features fewer patients needing massive amounts of blood, whereas other events feature more patients needing less support from blood products. Moreover, this pattern may not be apparent from simply looking at totals of blood product usage, which in this data set are no different.

Did we dispel the rumor that Biker Weekend uses more blood? I think the answer involves some nuance, as is often the case. Certainly, there are other aspects of Biker Weekend we did not track, such as trauma code activations, mortality, or trauma admissions, and this would be required to have a thorough understanding of the impact of Biker Weekend on local healthcare resources.

I think we can say that the truth is more complicated than the superstitions surrounding Biker Weekend. However, this will likely not stop surgery residents from arm wrestling over who has to take call when the Lonestar Rally comes to town.