Interpreting an underpowered trialBMJ 2008; 337 doi: https://doi.org/10.1136/bmj.a2957 (Published 11 December 2008) Cite this as: BMJ 2008;337:a2957
- John Fletcher, clinical epidemiologist
- 1BMJ, London WC1H 9JR
In a trial of a herbal treatment for symptoms of menopause the power calculation described in the protocol required 400 patients to be randomised. Unfortunately, recruitment was slow and the trial had to be stopped after 200 patients as funding was running out. Which if any of the following statements is true?
a) The possibility of a type one error is increased and the possibility of a type two …