Design of randomized controlled trials - Principles and methods applied toa treatment for early stuttering

The "gold standard" methodology for treatment efficacy research is the rand omized controlled trial (RCT), which is used extensively in medical researc h and in other areas such as psychology. Results from a well designed and c onducted RCT, which show a new treatment to be clinically and statistically superior to current standard practice, can lead to a change in clinical pr actice. This paper presents a tutorial on RCTs, presenting and discussing t he following principles and methods: the trial protocol, choice of control treatment, eligibility criteria, random allocation, outcomes and hypotheses , sample size, subject recruitment, analysis by intention to treat, interim analysis, stopping rules, safety data monitoring/trial management, and stu dy documentation. RCTs are a complicated and logistically involved methodol ogy. Hence, prior to the commitment of resources to such a trial in the dev elopment of a new treatment, the safety and clinical promise of the new tre atment needs to be demonstrated with preliminary studies. Such preliminary studies have been completed for the Lidcombe Program (I-P) of early stutter ing intervention, and an RCT of that treatment is being conducted at the ti me of writing. The principles and methods of RCTs are illustrated with refe rence to that study. Educational objectives: The reader will understand the design principles an d methods of RCTs. The reader will, understand the logistics of conducting a RCT of a treatment for early stuttering. (C) 2001 Elsevier Science Inc. A ll rights reserved.