Type-II error rates (beta errors) of randomized trials in orthopaedic trauma.

BACKGROUND: Although an investigator may limit bias through randomization, concealment of patient allocation, and blinding, the results of randomized trials may be less convincing when the sample size is not sufficiently large to reveal a true difference between treatment groups. When the sample size is small, randomized trials are subject to beta errors (type-II errors)--that is, the probability of concluding that no difference between …