Intended for healthcare professionals

Evidence That Really Matters

Ice cream evoked headaches (ICE-H) study: randomised trial of accelerated versus cautious ice cream eating regimen

BMJ 2002; 325 doi: (Published 21 December 2002) Cite this as: BMJ 2002;325:1445

Randomisation failure?

It is noteworthy that the cautious and accelerated eating groups have
very different male to female ratios. This difference is statistically
significant (P = 0.01, Fisher's exact test). I therefore wonder how robust
the randomisation procedure was. Was it possible that some of the study
participants cheated, and that the boys resorted to nefarious means to
ensure that they were included in the accelerated group?

In any case, given the large difference in the sex ratio between the
groups, the possibility exists that the result was due to confounding if
boys were more susceptible to ice-cream headache than girls.

Competing interests:  
None declared

Competing interests: No competing interests

23 December 2002
Adam Jacobs
Dianthus Medical Limited, London SW19 3TZ