Re: Bloodcurdling movies and measures of coagulation: Fear Factor crossover trial
The authors present an interesting study examining the effect of watching horror movies on pro-coagulant factor activation ("blood curdling"). However, whilest they measured degree of fear on a visual analog scale (to demonstrate that the horror movie was scarier than the educational film), they failed to examine the correlation between degree of fear and degree of pro-coagulant activation. Clearly, if a subject was immune to a horror movie (e.g. they were a horror movie fan), their pro-coagulant activity would remain unchanged. Conversely, a very fearful person would be expected to have a much higher pro-coagulant response, according to the authors' hypothesis.
Secondly, the authors fail to consider the prior probability of their hypothesis being feasible. John Ioannidis and others have eloquently shown that the probability that a statistically significant observed result is in fact a TRUE POSITIVE is directly related to the probability of such a result being possible, or probable. Therefore, I would postulate that the observation of a change in Factor VIII activity is due to chance, and not as a consequence of watching horror films.
This hypothesis of a false positive finding is supported by the observation that characters in horror films, who surely have a very high fear level at the time of their assault or demise, tend to bleed profusely, with copious blood spattering over the entire scene. This suggests that their pro-coagulant activity, whether up-regulated or not, does little to prevent the exsanguination to which they are subject.
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Re: Bloodcurdling movies and measures of coagulation: Fear Factor crossover trial
The authors present an interesting study examining the effect of watching horror movies on pro-coagulant factor activation ("blood curdling"). However, whilest they measured degree of fear on a visual analog scale (to demonstrate that the horror movie was scarier than the educational film), they failed to examine the correlation between degree of fear and degree of pro-coagulant activation. Clearly, if a subject was immune to a horror movie (e.g. they were a horror movie fan), their pro-coagulant activity would remain unchanged. Conversely, a very fearful person would be expected to have a much higher pro-coagulant response, according to the authors' hypothesis.
Secondly, the authors fail to consider the prior probability of their hypothesis being feasible. John Ioannidis and others have eloquently shown that the probability that a statistically significant observed result is in fact a TRUE POSITIVE is directly related to the probability of such a result being possible, or probable. Therefore, I would postulate that the observation of a change in Factor VIII activity is due to chance, and not as a consequence of watching horror films.
This hypothesis of a false positive finding is supported by the observation that characters in horror films, who surely have a very high fear level at the time of their assault or demise, tend to bleed profusely, with copious blood spattering over the entire scene. This suggests that their pro-coagulant activity, whether up-regulated or not, does little to prevent the exsanguination to which they are subject.
Competing interests: No competing interests