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A tutorial on pilot studies: the what, why and how

Lehana Thabane12*, Jinhui Ma12, Rong Chu12, Ji Cheng12, Afisi Ismaila13, Lorena P Rios12, Reid Robson3, Marroon Thabane14, Lora Giangregorio5 and Charles H Goldsmith12

Author Affiliations

1 Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton ON, Canada

2 Biostatistics Unit, St Joseph's Healthcare Hamilton, Hamilton ON, Canada

3 Department of Medical Affairs, GlaxoSmithKline Inc., Mississauga ON, Canada

4 Department of Medicine, Division of Gastroenterology, McMaster University, Hamilton ON, Canada

5 Department of Kinesiology, University of Waterloo, Waterloo ON, Canada

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BMC Medical Research Methodology 2010, 10:1  doi:10.1186/1471-2288-10-1

Published: 6 January 2010


Pilot studies for phase III trials - which are comparative randomized trials designed to provide preliminary evidence on the clinical efficacy of a drug or intervention - are routinely performed in many clinical areas. Also commonly know as "feasibility" or "vanguard" studies, they are designed to assess the safety of treatment or interventions; to assess recruitment potential; to assess the feasibility of international collaboration or coordination for multicentre trials; to increase clinical experience with the study medication or intervention for the phase III trials. They are the best way to assess feasibility of a large, expensive full-scale study, and in fact are an almost essential pre-requisite. Conducting a pilot prior to the main study can enhance the likelihood of success of the main study and potentially help to avoid doomed main studies. The objective of this paper is to provide a detailed examination of the key aspects of pilot studies for phase III trials including: 1) the general reasons for conducting a pilot study; 2) the relationships between pilot studies, proof-of-concept studies, and adaptive designs; 3) the challenges of and misconceptions about pilot studies; 4) the criteria for evaluating the success of a pilot study; 5) frequently asked questions about pilot studies; 7) some ethical aspects related to pilot studies; and 8) some suggestions on how to report the results of pilot investigations using the CONSORT format.