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Bloodcurdling movies truly curdle the blood: Results From
the Fear F8ctor Crossover Trial.
Journal: BMJ
Manuscript ID BMJ.2015.029359
Article Type: Christmas
BMJ Journal: BMJ
Date Submitted by the Author: 14-Sep-2015
Complete List of Authors: Nemeth, Banne; Leiden University Medical Center, Clinical Epidemiology; Leiden University Medical Center, Orthopedic Surgery Scheres, Luuk; Leiden University Medical Center, Department of Clinical Epidemiology; Academic Medical Center, Department of Vascular Medicine Lijfering, Willem; Leiden University Medical Center, Clinical Epidemiology
Rosendaal, Frits; Leiden University Medical Center, Clinical Epidemiology; Leiden University Medical Center, Einthoven Laboratory for Experimental Vascular Medicine
Keywords: Fear, Venous Thrombosis, Crossover Trial, Bloodcurdling, Factor VIII
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Bloodcurdling movies truly curdle the blood: Results from the
Fear F8ctor Crossover Trial
Banne Nemeth Medical doctor1,2
, Luuk JJ Scheres Medical doctor1,3
, Willem M Lijfering
Postdoctoral researcher1, Frits R Rosendaal Professor of Clinical Epidemiology 1,4
1.Department of Clinical Epidemiology, Leiden University Medical Center, 2300 RC, Leiden, The
Netherlands.
2.Department of Orthopaedic Surgery, Leiden University Medical Center, 2300 RC, Leiden, The
Netherlands.
3.Department of Vascular Medicine, Academic Medical Center, 1105 AZ, Amsterdam, The
Netherlands.
4.Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center,
2300 RC, Leiden, The Netherlands.
Address for correspondence: F.R. Rosendaal, Department of Clinical Epidemiology, Leiden
University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
Tel.: +31 71 526 4037; Fax: +31 71 526 6994
Email: [email protected]
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Abstract
Objectives – To unravel if acute fear curdles the blood as has been hypothesized since medieval
times.
Design – A crossover trial in which one group of participants was exposed to a frightening (scary)
movie followed by a non-frightening (flat) movie. Another group of participants watched the movies
in opposite order. The second movie was watched at least one week after the first movie on the same
time of the day.
Setting – The movies were shown to participants who were seated in comfortable chairs, at the Home
Cinema of the Department of Epidemiology, which generally carries a non-frightening and relaxed
atmosphere.
Participants – 24 healthy participants, not on any medication, aged ≤30 years were recruited among
students, alumni and employees of the Leiden University Medical Center.
Interventions – A frightening movie, with potential of inducing acute fear and a non-frightening
(although educational), flat movie were carefully selected. Both movies had a length of approximately
90 minutes.
Main outcome measures – Primary outcome measures were markers of coagulation activity (i.e.,
potential coagulation fear factors): Factor VIII (FVIII:C), D-dimer, Thrombin and Antithrombin
complexes (TATc) and Prothrombin fragments 1 + 2 (F1+2). Secondary outcomes were pulse rates
measured during both movies and a Visual Analogue Fear Scale (VAFS) on fear experienced during
each movie.
Results – All study participants completed the study. The frightening movie was perceived more
frightening than the non-frightening movie (VAFS mean difference 5.4 [95%CI 4.7 – 6.1]). FVIII:C
levels (i.e., the difference between levels before and after the movie) were higher after the frightening
movie than after the non-frightening movie (mean difference of differences 11.2 IU/dL [95%CI 1.8 to
20.7]). There was no difference in effect of either type of movies on levels of TATc, D-dimer and
F1+2.
Conclusions – Fear is bloodcurdling.
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Introduction
“Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so
that we may fear less.” Marie Curie, 1867-1934.[1]
For centuries the term “bloodcurdling” has been used to describe extreme frightening situations.[2] It
is known in several other languages of which “das blut in den Adern erstarrt”, “à vous glacer le sang”,
“que hiela la sangre” and “bloedstollend” are examples in German, French, Spanish and Dutch,
respectively. The term dates back to the concepts in medieval physiology, where it was believed that
the human body contained four chief fluids, blood, phlegm, bile and black bile. It was thought that
fear or horror would ‘run the blood cold’ or ‘curdle’ (solidify).[3] To date large parts of the complex
mechanism of the coagulation cascade have been unravelled and many risk factors for thrombosis
have been identified. However, the origin of this medieval theory has never been studied and it
remains unknown if fear truly induces the coagulation system and thereby curdles the blood.
Several studies explored the effects of physical stress on the coagulation system.[4] Chronic anxiety
in psychiatric patients was associated with increased levels of coagulation markers in several
studies.[5,6] However, chronic anxiety in psychiatric patients (with associated therapies) markedly
differ from a state of acute fear in the community. In another study investigators studied coagulation
markers before and after bungee jumping, and reported increased coagulation activity in apparently
healthy volunteers after the jump. [7] However, the effects of excitement and profound physical
activity are not necessarily equal to those of acute fear, in particular because, as was pointed out, these
individuals performed these jumps voluntarily, which was seen as deviating from an ideal design.[8]
To our knowledge, till date no studies investigated acute fear without physical exercise and the effects
on the coagulation system. We hypothesize that acute fear induces activation of the coagulation
system as this would pose an important evolutionary benefit, which is preparing for blood loss in
frightening and life-threatening situations.
People often experience fear in acute situations in which coagulation plays a crucial role, such as
events of severe bleeding due to trauma or haemorrhagic diathesis. Fear may also play a role in other
unexplained disturbances of the coagulation cascade that might lead to venous thrombosis, as is the
case in aviation.[9]
Here we present results from a crossover trial which was conducted to unravel the effect of acute fear
on the coagulation cascade (and to identify candidate fear factors), and to investigate whether fear is
truly bloodcurdling, as was hypothesized centuries ago.
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Methods
Study design
Between, the 29th of June and the 20th of August, 2015, a crossover trial was performed. Twenty-four
healthy volunteers were recruited. One group (n=14) of participants first watched a frightening movie
(i.e. bloodcurdling) followed by a non-frightening movie. The other group (n=10) watched the same
movies in opposite order. Group allocation was based on availability of the study participants as
movie nights were set on specific dates. Figure 1 is a flow chart of the study design. Both movies
lasted for approximately 90 minutes and were watched at least one week apart, on the same time of
day (see flow chart). Both groups were seated in the same comfortable chairs. The participant
information leaflet revealed that this was a study in which the coagulation effects of sitting still and
watching movies was analysed. However, participants were not aware of the movie genre in advance.
Participants were also not informed that the actual goal was to determine if a frightening movie could
curdle the blood. A frightening movie was selected carefully on fear provoking potential with an
external expert and was agreed upon by the two investigators. The non-frightening movie was
selected by two investigators for its non-emotional provoking capacity and was (although
educational), a flat (and rather dull) movie (The authors’ Christmas movie reviews are provided in
supplementary text 1 and supplementary figure 1). Before and after each movie, blood was drawn
through venepuncture of the cubital vein (in the contralateral arm for the second draw). The movies
were shown at the main meeting room, which was transformed into the Home Cinema of the
Department of Clinical Epidemiology of the Leiden University Medical Center, which emits a non-
frightening and welcoming atmosphere. Participants were instructed not to consume alcohol, smoke
or use any drugs on both movie days. In order to avoid any confounding by superstition, no movies
were shown during full moon or on Friday the 13th. All participants provided written informed
consent. This study was approved by the Medical Ethical Committee of the Leiden University
Medical Center in Leiden, The Netherlands.
Study population
Healthy volunteers, aged < 30 years were recruited among students, alumni and employees of the
Leiden University. Participants were not on any medication, not pregnant (or up to 6 weeks after
pregnancy), used no hormonal contraceptives (excluding intra-uterine devices), had no history of
venous thrombosis, had no major surgery or cast-immobilization of the lower extremity in the past
two months and did not have a malignancy or inflammatory disease.
Laboratory measurements
Measured markers of coagulation activity (e.g. potential fear factors) were factor VIII activity in
IU/dL (FVIII:C) , D-dimer in ng/mL, Thrombin and Antithrombin complexes (TATc) in ug/L and
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Prothrombin fragments 1 + 2 in in pmol/L (F1+2). Blood samples were drawn in vacuum tubes
containing 0.105M additive of Na Citrate. After blood collection, we centrifuged citrated blood at
2500 g for 10 minutes at 18°C within 1 hour of venepuncture. After aliquoting, samples were stored at
-80°C until laboratory analyses were performed. F1+2 and TATc laboratory analyses were performed
within one batch, all laboratory analyses were measured in duplicate. The clotting assay for FVIII:C
and D-dimer was performed using the TOP analyser (Werfen Group/Instrumentation Laboratory,
Barcelona Spain). TATc and F1+2 were assayed via sandwich-type ELISA (Siemens, Marburg,
Germany). The laboratory technicians were not aware of which movie corresponded to which blood
sample.
Fear scale and questionnaire
After each movie a Visual Analogue Fear Scale (VAFS), designed for this specific study,
(supplementary figure 2) was completed by every participant. The VAFS estimates fear experienced
by watching the movie, ranging from no fear at all (VAFS:0) to the worst fear imaginable (VAFS:10).
Additionally, participants reported whether they had already seen the movie and whether they enjoyed
the movie on a scale from 0 (worst movie ever) to 10 (best movie ever). Finally, participants
completed an questionnaire on demographics, lifestyle and favourite movie genre.
Heart rate monitoring
In one of the groups, heart rates were measured every 15 seconds in six randomly chosen participants
by means of an Actihearts device (CamnTech Ltd). Due to limited availability of these devices, heart
rates were not measured in all participants.
Sample size calculation
Sample size was calculated for the continuous outcome variables FVIII:C (2-sided test, alpha=0.05,
beta=0.9). In order to observe an increase of 10 IU/dL of more (leading to an increase in venous
thrombosis risk of around 17%)10
, a total of 23 participants were necessary. Anticipating possible
drop-out of participants, we included a total of 24 participants.
Statistical analyses
Demographic and baseline data (e.g., age, sex, weight and height) were summarized as means ±
standard deviation (SD) or proportions. Body Mass Index (BMI) was calculated based on self-
reported height and weight. Mean changes in the measured coagulation markers were assessed as
levels before and after each movie. The difference between the mean change in coagulation levels
(mean change of levels before and after frightening movie compared with the mean change before and
after non-frightening movie) were compared. A paired student t-test was used to compare the two
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mean changes in these coagulation markers. For the VAFS we reported the mean change and 95%
confidence intervals (95%CI). The coagulation factor levels were similar in the group who first
watched the frightening movie followed by the non-frightening movie as compared with the group
who watched these movies in opposite order (results not shown). Therefore, a carry-over effect was
considered absent. For this reason, results of both study arms were pooled by type of movie exposure.
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Results
Participants and recruitment
In total, 24 healthy volunteers were recruited between July 20 and August 12. Study days took place
on July 29, August 4, 5 and 11, all movies were shown between 19:00 and 21:00. Due to the
availability of participants, 14 volunteers were recruited for group A ( frightening movie first), and 10
volunteers for group B (non-frightening movie first). Table 1 shows baseline demographics. The
mean age of the participants was 25.9 years (SD 3.0), 16/24 (67%) were males. All volunteers were
healthy and did not use medication.
Table 1. Baseline characteristics
Table 1 | Study participant demographics
Demographics
Sex - male (%) 16 (67)
Age in years (mean (SD)) 25.9 (3.0)
Height in meters (mean (SD)) 1.81 (0.12)
Weight in kilograms (mean (SD)) 77.6 (11.8)
Body Mass Index 23.4 (2.5)
Smoking - Yes (%) 2 (8.3%)
Cigarettes per day
1-5 1
6-10 -
11-15 -
16-20 1
Alcohol - Yes (%) 19 (79.2)
Alcohol units per week
1-5 7
6-10 7
11-15 3
16-20 1
21-25 -
26-30 1
Coffee - Yes (%) 19 (79.2)
Cups of coffee per day
1-3 12
4-6 6
7-9 1
Favorite movie genre (number (%))
Action 7
Adventure 1
Thriller 3
Romantic Comedy 5
Science Fiction 2
Comedy 4
Fantasy 1
Drama 1
Horror movie fan - Yes (%) 5 (20.8)
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Frightening movie
VAFS (mean (SD)) 5.4 (1.7)
Movie Score (mean (SD)) 4.25 (4.3)
Already have seen movie - Yes (%) 3 (12.5)
Non-frightening movie
VAFS (mean (SD)) 0.0 (0.2)
Movie Score (mean (SD)) 5.1 (1.7)
Already have seen movie - Yes (%) 0 (0)
VAFS=Visual Analogue Fear Scale, SD=Standard deviation
Two participants were smokers and 80% consumed alcohol and coffee on a regular basis. Five
volunteers were horror movie fans. Action or romantic comedy were favourite movie genres for 7 and
5 participants, respectively.
The frightening movie was experienced as quite frightening with a mean VAFS of 5.4 (SD 1.7). Only
three participants had already seen this movie. The mean VAFS of the non-frightening movie was 0.0
(SD 0.2) and not a single participant had already seen this movie. There was a difference in fear
experienced between the movies, with more fear experienced during the frightening movie (mean
difference of VAFS: 5.4 (95%CI 4.7 – 6.1).
Fear F8ctor analyses – primary outcome measures
Three participants were excluded from the primary fear f8ctor analyses. In the first two cases (group
B), of both participants one of the samples was visibly haemolytic as noted by the laboratory
technicians, and the results were considered to be unreliable. In the third case, the first two authors
noted (a-priori) that the participant was very tense before the first blood draw (before the non-
frightening movie) and in attempt to relax before the second blood draw he ingested an entire family
pack of chocolates after the first blood draw. He suffered from vasovagal reflexes and fainted during
the blood draw after the first movie. At the second movie (the frightening movie) these symptoms
were not noted. Since the assumption for a crossover trial, i.e. both instances similar except for the
intervention, was clearly not met for this individual, results were regarded as unusable (FVIII:C 132
IU/dL before the first movie and 346 IU/dL after, and 109 IU/dL before and 123 IU/dL after the
frightening movie, respectively).
After exclusion, the remaining 21 participants were included in the main analyses. Mean FVIII:C
baseline levels were similar before the frightening and the non-frightening movie (mean difference -
2.9 IU/dL (95%CI -10.1 ; 4.2). However, the mean change in FVIII:C levels (i.e., the difference
between levels before and after movie) was higher after the frightening movie than for the non-
frightening movie (mean difference 11.1 IU/dL [95%CI, 1.2 to 21.0]). Figure 2A shows the mean
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change in FVIII:C levels before and after the frightening and non-frightening movie. As can been
appreciated from this figure, FVIII levels increased in 12 (57%) participants during the frightening
movie, and in only 3 (14%) during the educational movie. In 18 (86%) participants, FVIII:C levels
declined during the non-frightening movie, which happened in only 9 (43%) participants during the
frightening movie.
Mean D-dimer levels before the frightening and non-frightening movie were similar. The mean
change in D-dimer levels before and after the non-frightening movie was -35.1 ng/mL (SD 63.0) and -
31.8 (SD 109.3) before and after the frightening movie. So, no effect of acute fear on D-Dimer levels
was observed (Figure 2B), mean difference 3.33 ng/mL [95%CI -37.1 to 43.8]).
There was also no effect on TATc levels, mean difference of differences -0.54 µg/L ; 95%CI -2.5 to
1.4), (Figure 2C). In these healthy participants, of all F1+2 measurements (before and after both
movies), all but two were below 200 pmol/L. The mean change in F1+2 levels (Figure 2D) before
and after the non-frightening movie was -10.2 pmol/L (median -1.0), the mean change after the
frightening movie was -23.7pmol/L (median -21).
Fear F8ctor analyses – validation of physiological effect of fear
Heart rates were monitored every 15 seconds in 6 study volunteers, both during the non-frightening
and frightening movie. Figure 3 represents the heart rate of two study participants during both
movies. One participant reported an 8 on the VAFS after experiencing a bloodcurdling movie and
scored, the other participant found the frightening movie rather non-frightening and scored a 1 on the
VAFS. Scary scenes were identified by one of the investigators before examining the heart rates. As
can be seen in the figure, the heart rate elevated during scary scenes in the participant which reported
to have experienced fear during the movie. This was not true for the participant who did reported a
low VAFS.
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Discussion
With this rigorously designed study we demonstrate that bloodcurdling fear, truly curdles the blood.
We successfully attempted to design a study to expose participants to undiluted and acute fear in the
absence of physical exertion. Without exception participants reported the frightening movie to be
more frightening than the educational movie. We attempted to identify coagulation fear factors,
entities which may mediate the effects of fear into curdling of the blood. We observed an increase in
one of the candidate fear factors, traditionally know as factor VIII of the coagulation cascade, when
exposing participants to a frightening movie. Increased factor VIII activity has been associated with
increased venous thrombosis risk.[10–12] Therefore, the mean increase in FVIII:C of 11.1 (IU/dL) in
these healthy participants exposed to acute fear could well be clinically relevant, as was previously
reported that for every 10 IU/dL increase in factor VIII:C levels the risk of venous thrombosis
increased 17% (95%CI 7-28).[10] Therefore, we consider factor VIII to be a blood curdling fear
factor. D-dimer, TATc and F1+2 levels were not different before and after both exposures, and did not
prove themselves to be an acute coagulation fear factor. As blood was drawn directly after the
exposures, it is possible that these latter coagulation markers were not increased due to a latent period.
Moreover, the role for increased F1+2 levels as a risk factor for venous thrombosis remains uncertain,
as there have been conflicting results from studies.[13–15]
As mentioned, in most participants FVIII:C dropped during the non-frightening movie. The
participants were sitting still while watching a flat and a non-emotion-provoking movie. This relaxed
circumstance may even have led to the decrease in FVIII:C that was observed. A similar, however
more extreme, example of this phenomenon was observed in animals during hibernation, which
causes a rapid reversible thrombocytopenia.[16] It has been hypothesized that decreased coagulation
activity in hibernators protects against thrombosis during prolonged immobilization.[17] Our study
was not designed to explore this phenomenon, and room temperature was maintained during the
study, but the finding in man is intriguing.
A strength of this study is its cross-over design, which allows each case to be its own control. By
showing the movies (one week apart) on the same day and time of the week, we expect no influence
of circadian rhythms and lifestyle on the study results. A limitation of the study could be the
magnitude of fear induced by the exposure. Although some participants scored a 7 or 8 on the VAFS,
there is definite room for fear enhancement. Perhaps an increasingly frightening situation would
provoke an even more blood curdling response. However, such designs might elicit ethical
controversy and would be likely to be confounded by increased physical activity.
The underlying biological mechanism of acute fear resulting in increased coagulation activity is still
to be unravelled. However, these results are biologically and evolutionary plausible. Increased activity
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of the coagulation system when experiencing frightening situations might pose an important
evolutionary benefit: preparing for blood loss in frightening situations. Desmopressin, a vasopressin
analogue, has been used to increase coagulation activity in a wide range of bleeding diathesis.[18]
Desmopressin stimulates von Willebrand factor release with increased factor VIII levels as a
result.[19] A biological mechanism explaining these study results might be related to this pathway.
Although not immediately obvious by which means our results could confer clinical benefits, a
broader implication of these study results is that after centuries the term: “bloodcurdling” in literature
is justified.
Conclusions
This study shows that acute fear truly curdles the blood.
“What this paper adds box”
1.What is already known on this subject
As early as in medieval times it was thought that fear induced curdling (solidifying) of the blood.
Several studies have reported increased coagulation profiles in times of physical or psychological
stress, however the effect of pure fear on the coagulation system is still unravelled.
2.What this study adds
Acute fear seems to be truly bloodcurdling, as evidenced by increases in coagulation factor VIII.
These findings may necessitate development of preventive strategies to reduce fear in individuals at
risk for thrombosis. In terms of the season, a true relaxing merry Christmas, without exposure to
fright, seems to be safe to prevent venous thrombosis.
Contributors
According to good epidemiological practice, the decision of who would be first and who would be
second author was made by randomization. All authors were involved in the study design, study
conduct, data analysis, and revision of the manuscript. All authors read and approved the final
manuscript.
Acknowledgements
We would like to thank Nine Nemeth, Maaike Hermans and Liesbeth Willems of Brilman – Tuinhof
de Moed for their help with blood collection. Petra Noordijk, Annelies Hoenderdos and Lejla Mahic
for laboratory analyses, Selina Wijbenga and Yanna van der Spek for accompanying frightened study
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participants and Eva Rosendaal for her expertise in horrorology. This study could not have been
performed without all participants, whom we would like to gratefully thank for their participation in
the study.
Funding
This study was sponsored by the Department of Clinical Epidemiology of the Leiden University
Medical Center.
Competing interest
All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf
and declare: no support from any organisation for the submitted work; no financial relationships with
any organisations that might have an interest in the submitted work in the previous three years; no
other relationships or activities that could appear to have influenced the submitted work.
Ethical approval
All participants provided written informed consent. This study was approved by the Medical Ethical
Committee of the Leiden University Medical Center in Leiden, The Netherlands.
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18. Mannucci PM, Ruggeri ZM, Pareti FI, Capitanio a. 1-Deamino-8-d-arginine vasopressin: a
new pharmacological approach to the management of haemophilia and von Willebrands’
diseases. Lancet. 1977;1(8017):869–72.
19. Mannucci PM. Desmopressin (DDAVP) in the Treatment of Bleeding Disorders: The First 20
Years. Blood. 1997;90(7):2515–21.
20. Anand G, Shefler A, McShane T. Diagnosis and outcome of children admitted to a paediatric intensive care unit with unexplained coma. Arch Dis Child. 2011;96(11):1091.
21. Pomp ER, Rosendaal FR, Doggen CJM. Alcohol consumptionisassociated witha decreased
risk of venous thrombosis. Thromb Haemost. 2008;99(1):59–63.
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Figures
Figure 1 title
Flow chart study design
Figure 1 Legend
Study flowchart: 24 participants were recruited, group allocation was based on availability of the
study participants as movie nights were set on specific dates. Fourteen participants were exposed to
the frightening movie and one week later to the non-frightening movie. The remaining 10 participants
saw the movies in opposite order, also one week apart. Blood was drawn before the first movie (T0),
directly after (T1) and before (T2) and directly after (T3) the second movie.
Figure 2 Title
Mean difference in coagulation fear factors before and after the frightening and non-frightening
movies.
Figure 2 Legend
2A: Absolute mean change in coagulation factor FVIII:C after exposure to a frightening and non-
frightening movie (ordered by change in FVIII:C levels during frightening movie). Vertical bars
represent individual participants, the order of participants is identical in all graphs (also for 2B, 2C
and 2D). *-96 FVIII IU/dL difference, ** -27 FVIII IU/dL difference.
2B: Absolute mean change in coagulation D-dimer (after frightening and non-frightening movie).
2C: Absolute mean change in coagulation TATc (after frightening and non-frightening movie).
2D: Absolute mean change in coagulation F1+2 (after frightening and non-frightening movie).
Figure 3 Title
Heart rates (beats per minute) of two participants
Figure 3 Legend
Heart rate (beats per minute) during frightening and non-frightening movie in two participants. The
top panel shows the heart rate for a participant that scored an 8 on the VAFS for the frightening
movie. The lower panel shows the heart rate for a participant that scored a 1 on the VAFS on the
frightening movie.
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Supplements
Supplementary text 1, Author’s Christmas Movie Suggestions
Frightening movie
A happy family moves into a new home and all is well. At an unfortunate moment, one of the children
falls from a ladder and suffers from an unexplained coma. The doctors at the hospital struggle to
figure out the cause of the coma, but did not consider that the boy has left his physical body and is
lost in a different dimension (authors note: a cause not yet listed in the differential diagnosis of
unexplained coma in children).[20] Evil spirits start haunting the family and events soon turn grim.
Will the boy be rescued? How will the family stand against these evil spirits? Cuddle under your
blanket around the Christmas tree and find out, but be sure to keep those calf veins pumping!
Non-frightening movie
This movies’ plot revolves around an esteemed wine importer who visits several famous Champagne
houses in the Champagne region in France. The movie focusses on the production process of
Champagne and the rise of the champagne industry. An absolute recommendation for all who want to
learn more about the world’s favourite new years’ beverage. Be sure to impress your peers during the
soon to come New Year’s party with the know-how from this movie! (authors note: although alcohol
consumption was associated with decreased venous thrombosis risk,[21] we did not expect this movie
to curdle the blood.)
Supplementary figure 1 Title
The authors’ judgement
Supplementary figure 1 Legend
The Authors’ judgement of the movies are shown in this figure, based on blood curdling potential,
storyline and educational potential. Two authors critically reviewed both movies and attributed stars
to each category. More stars indicate higher appraisal.
Supplementary figure 2 Title
Visual analogue fear scale (VAFS)
Supplementary figure 2 Legend
The visual analogue fear scale (VAFS) developed by the authors to measure fear after each movie.
Participants indicated the amount of fear experienced during the movie, directly after watching both
movies. A higher number indicates more fear experienced.
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Flow chart study design /
Study flowchart: 24 participants were recruited, group allocation was based on availability of the study participants as movie nights were set on specific dates. Fourteen participants were exposed to the
frightening movie and one week later to the non-frightening movie. The remaining 10 participants saw the movies in opposite order, also one week apart. Blood was drawn before the first movie (T0), directly after
(T1) and before (T2) and directly after (T3) the second movie. 292x268mm (300 x 300 DPI)
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Mean difference in coagulation fear factors before and after the frightening and non-frightening movies. /
2A: Absolute mean change in coagulation factor FVIII:C after exposure to a frightening and non-frightening movie (ordered by change in FVIII:C levels during frightening movie). Vertical bars represent individual participants, the order of participants is identical in all graphs (also for 2B, 2C and 2D). *-96 FVIII IU/dL
difference, ** -27 FVIII IU/dL difference. 2B: Absolute mean change in coagulation D-dimer (after frightening and non-frightening movie). 2C: Absolute mean change in coagulation TATc (after frightening and non-frightening movie). 2D: Absolute mean change in coagulation F1+2 (after frightening and non-frightening movie).
402x148mm (300 x 300 DPI)
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Heart rates (beats per minute) of two participants /
Heart rate (beats per minute) during frightening and non-frightening movie in two participants. The top panel shows the heart rate for a participant that scored an 8 on the VAFS for the frightening movie. The lower panel shows the heart rate for a participant that scored a 1 on the VAFS on the frightening movie.
462x222mm (300 x 300 DPI)
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Frightening movie A happy family moves into a new home and all is well. At an unfortunate moment, one of the children falls from a ladder and suffers from an unexplained coma. The doctors at the hospital struggle to figure out the
cause of the coma, but did not consider that the boy has left his physical body and is lost in a different dimension (authors note: a cause not yet listed in the differential diagnosis of unexplained coma in
children).[20] Evil spirits start haunting the family and events soon turn grim. Will the boy be rescued? How will the family stand against these evil spirits? Cuddle under your blanket around the Christmas tree and find
out, but be sure to keep those calf veins pumping! Non-frightening movie
This movies’ plot revolves around an esteemed wine importer who visits several famous Champagne houses in the Champagne region in France. The movie focusses on the production process of Champagne and the rise of the champagne industry. An absolute recommendation for all who want to learn more about the
world’s favourite new years’ beverage. Be sure to impress your peers during the soon to come New Year’s party with the know-how from this movie! (authors note: although alcohol consumption was associated with
decreased venous thrombosis risk,[21] we did not expect this movie to curdle the blood.)
328x336mm (300 x 300 DPI)
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Visual analogue fear scale (VAFS) /
The visual analogue fear scale (VAFS) developed by the authors to measure fear after each movie. Participants indicated the amount of fear experienced during the movie, directly after watching both movies.
A higher number indicates more fear experienced. 213x34mm (300 x 300 DPI)
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nlySupplementary text 1, Author’s Christmas Movie Suggestions
Frightening movie
A happy family moves into a new home and all is well. At an unfortunate moment, one of the children
falls from a ladder and suffers from an unexplained coma. The doctors at the hospital struggle to figure
out the cause of the coma, but did not consider that the boy has left his physical body and is lost in a
different dimension (authors note: a cause not yet listed in the differential diagnosis of unexplained coma
in children).[20] Evil spirits start haunting the family and events soon turn grim. Will the boy be rescued?
How will the family stand against these evil spirits? Cuddle under your blanket around the Christmas tree
and find out, but be sure to keep those calf veins pumping!
Non-frightening movie
This movies’ plot revolves around an esteemed wine importer who visits several famous Champagne
houses in the Champagne region in France. The movie focusses on the production process of Champagne
and the rise of the champagne industry. An absolute recommendation for all who want to learn more
about the world’s favourite new years’ beverage. Be sure to impress your peers during the soon to come
New Year’s party with the know-how from this movie! (authors note: although alcohol consumption was
associated with decreased venous thrombosis risk,[21] we did not expect this movie to curdle the blood.)
20. Anand G, Shefler A, McShane T. Diagnosis and outcome of children admitted to a paediatric
intensive care unit with unexplained coma. Arch Dis Child. 2011;96(11):1091.
21. Pomp ER, Rosendaal FR, Doggen CJM. Alcohol consumptionisassociated witha decreased risk of
venous thrombosis. Thromb Haemost. 2008;99(1):59–63.
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