Allocation biasBMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b2162 (Published 03 June 2009) Cite this as: BMJ 2009;338:b2162
- John Fletcher, clinical epidemiologist
- 1BMJ, London WC1H 9JR
Which, if any, of the following methods is unlikely to introduce bias in the allocation of people to treatments in a trial?
a) People are matched according to age and sex, and for each person allocated to one treatment, a matching person is allocated to the other
b) The clinician treating the person tosses a coin to decide which treatment to give
c) People whose initial letter of their last name is in the first half of the alphabet …