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Table 2 Reasons for conducting pilot studies

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

Main Reason


Process: This assesses the feasibility of the processes that are key to the success of the main study

• Recruitment rates


• Retention rates


• Refusal rates


• Failure/success rates


• (Non)compliance or adherence rates


• eligibility criteria


   - Is it obvious who meets and who does not meet the eligibility requirements?


   - Are the eligibility criteria sufficient or too restrictive?


• Understanding of study questionnaires or data collection tools:


   - Do subjects provide no answer, multiple answers, qualified answers, or unanticipated answers to study questions?

Resources: This deals with assessing time and resource problems that can occur during the main study

• Length of time to fill out all the study forms


• Determining capacity:


   - Will the study participants overload your phone lines or overflow your waiting room?


• Determining process time


   - How much time does it take to mail out a thousand surveys?


• Is the equipment readily available when and where it is needed?


• What happens when it breaks down or gets stolen?


• Can the software used for capturing data read and understand the data?


• Determining centre willingness and capacity


   - Do the centres do what they committed to doing?


   - Do investigators have the time to Perform the tasks they committed to doing?


   - Are there any capacity issues at each participating centre?

Management: This covers potential human and data management problems

• What are the challenges that participating centres have with managing the study?


• What challenges do study personnel have?


• Is there enough room on the data collection form for all of the data you receive?


• Are there any problems entering data into the computer?


• Can data coming from different sources be matched?


• Were any important data values forgotten about?


• Do data show too much or too little variability?

Scientific: This deals with the assessment of treatment safety, dose, response, effect and variance of the effect

• Is it safe to use the study drug/intervention?


• What is the safe dose level?


• Do patients respond to the drug?


• What is the estimate of the treatment effect?


• What is the estimate of the variance of the treatment effect?