DITORIAL Expert Opinion (Eg, Dr Daryl Dixon Reports That the Bolt Ment Industry and Did Not Provide Evidence for Mortality

Volume 51 & Number 1 & February 2019 7

Of Zombies and Evidence DaiWai M. Olson, John C. Bazil

espite anecdotal evidence seen on television and research. Intellectual honesty enhances the value of meta- in movies, there is zero actual research to support analyses by including results from every study (those that D penetrating traumatic brain injury (TBI) as an in- reject the null hypothesis as well as those failing to reject tervention to kill zombies (eg, walkers). For the moment, we the null hypothesis). For example, we would expect to shall dispense with the obvious conundrum that one cannot read a systematic review that includes data from the highly kill (end the life of) someone or something that is already successful Hilltop Study, mixed results from the Alexandria dead. Rather, we shall focus on the concept of evidence. Effort, and results from the failed Sanctuary Trial.2 Evidence is nothing more than a collection of facts. Thanks to Internet and high-speed computing, nurses can These facts may be minor or major and may stem from a quickly and efficiently determine for themselves what evidence variety of sources. A wide variety of models have been pro- is available to support any given position. An October 2018 E posed to describe the hierarchy of evidence types. Of these search of PubMed found 138 articles included the keyword various models, the pyramid shape is probably most familiar ‘‘zombie.’’ Of these, only 1 was listed as a clinical trial.3 Upon to nursing. The base and least rigorous form of evidence is inspection, this was a study about the zombie entertain- DITORIAL expert opinion (eg, Dr Daryl Dixon reports that the bolt ment industry and did not provide evidence for mortality. from a crossbow will kill walkers).1 It is important to note Again, it can be noted that there are difficulties involved that the expert is often simply the person who happens to with evidence collection regarding the issue of the definition have the stage or the pen or to be a bully pulpit. of death on a nonliving being. Perhaps, the limitation is The next level of evidence is typically case studies and that this is not an intervention with adequate preclinical nonrandomized research. At this level, you may read a data, or perhaps the theory is flawed. Because of the lack of report by Grimes et al describing a case in which ‘‘...a knife research data, the only evidence available is expert opinion. thrust through the anterolateral skull proximal to Kocher’s Thus, we conclude that, if we were attacked by a horde of point resulted in death.’’ Additional evidence comes in the walkers, our best evidence-based practice option would be form of nonrandomized research such as observational to use a skull-penetration intervention (class of evidence, trials without control. For example, a group of nurses may level IIB; strength of recommendation, level C). collaborate to collectively clear a hospital wing of walkers via skull penetration with hemostats. Despite observing a 100% kill rate, there are key questions that remain un- answered: Is another method equally effective? How deep must the instrument penetrate (eg, dura mater, cerebral cortex, basal ganglia, or brainstem)? Does instrument size moderate the effect (do large diameter crowbars have higher odds ratio of killing compared with small bore arrows)? The prospective randomized clinical trial is the next level of evidence and often used to test hypotheses that were de- veloped from nonrandomized studies. For example, a ran- The authors declare no conflicts of interest. domized clinical trial may be designed to only stab half the walkers in the head and hit the other half with baseball bats References (blunt nonpenetrating TBI) and thereby test the hypothesis 1. Coleman RC. The Walking Dead. Arrow on the doorpost. Season 3, that the proportion of walker death is statistically significantly episode 13. Director: Boyd, D. Fox Networks Group. March 10, 2013. higher after open TBI versus closed TBI. One could design a 2. Kirkman R, Adlard C. The Walking Dead: A New Beginning. test of open TBI versus no injury (control), but this would Vol 22, 12 7Y132. Image Comics; 2014. probably not receive institutional review board approval 3. Houghton F, Toms J, Meratnia G, Loney K, Hopkins E, Del because of an increased risk to the research staff. Monte K. Concerns with entertainment-education: Zombie pandemic preparedness and the unanticipated promotion of a The highest level of evidence is systematic review or weapons culture. Health Educ Behav. 2017;44(4):519Y523. meta-analysis. These articles synthesize and statistically summarize the accumulated data from all the available DOI:10.1097/JNN.0000000000000421