Friday Foolery #11. Is Friday the 13th bad for your Health?

13 11 2009

3360459431_c3ec229cd1 Friday the 13th

Is Friday the 13th bad for your health?

Apparently it is, at least according to a study published in the BMJ in 1993 [1].
This retrospective study comparing driving and shopping patterns and accidents shows that Friday 13th is unlucky for some. Despite that there were consistently and significantly fewer vehicles on the southern section of the M25 on Friday the 13th compared with Friday the 6th, the admissions due to transport accidents were significantly increased on Friday 13th (total 65 v 45; p < 0.05). Since the risk of hospital admission as a result of a transport accident may be increased by as much as 52%, staying at home is recommended by the authors.

In a related article (PubMed) in the Am J Psychiatry (2002), deaths from Finnish traffic accidents on Friday the 13th were compared with those on other Fridays. Here a difference was found between men and women. In men, the adjusted risk ratio for dying on Friday the 13th, compared with other Fridays, was 1.02, (no difference) but for women, it was 1.63. An estimated 38% of traffic deaths involving women on this day were attributable to Friday the 13th itself.
Therefore again this author concludes that Friday the 13th may be a dangerous day, but only for women. The author thinks this is  largely because of anxiety from superstition. Although the risk of traffic deaths on this date could be reduced by one-third, the absolute gain would remain very small: only one death per 5 million person-days.

Other Finnish researchers reinvestigated this finding, but they also looked at the injury accident database, because this database contains much more data than the fatality database. They reasoned that if there was a Friday-the-13th effect by impaired psychic and psychomotor functioning due to more frequent anxiety among women, it should also appear in the number of injury crashes. They found no consistent evidence for females having more road traffic crashes on Fridays the 13th, based on deaths or road accident statistics. Still, since an effect of superstition related anxiety on accident risk can not be excluded, the authors conclude that people who are anxious of “Black Friday” may stay home, or at least avoid driving a car.

Well at least you now know what scientific research says about Friday the 13th, or uuh don’t you?
At least, females suffering from Paraskevidekatriaphobia or even Triskaidekaphobia should better stay at home. You know, just in case…



  1. Scanlon TJ, Luben RN, Scanlon FL, Singleton N. Is Friday the 13th bad for your health? BMJ. 1993 Dec 18-25;307(6919):1584-6.
  2. Näyhä S. Traffic deaths and superstition on Friday the 13th. Am J Psychiatry. 2002 Dec;159(12):2110-1.
  3. Radun I, Summala H. Females do not have more injury road accidents on Friday the 13th. BMC Public Health. 2004 Nov 16;4:54.
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3 responses

14 11 2009
Tweets that mention Friday Foolery #11. Is Friday the 13th bad for your Health? « Laika’s MedLibLog --

[…] This post was mentioned on Twitter by Walter van den Broek, Laika (Jacqueline) and Laika (Jacqueline), ehealthgr. ehealthgr said: RT @laikas Blogging: Friday Foolery #11. Is Friday the 13th bad for your Health? (lol. nice one @laikas ^_^) […]

14 11 2009
1 02 2010
#NotSoFunny – Ridiculing RCTs and EBM « Laika’s MedLibLog

[…] Friday Foolery #11. Is Friday the 13th bad for your Health? ( […]

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