Core Guide: Pilot and Feasibility Studies (Duke Global Health Institute - Research Design & Analysis Core). Prepared by Alyssa Platt and Rachel D’Anna (Version 2.0 - May 2, 2022): 16-page guidance document.

• Summary: To help address the varied use of terminology, this guide provides definitions of feasibility studies and pilot studies with a focus on randomized trials. It unpacks differences between pilot and feasibility studies, and the types of objectives researchers often have when completing one type of study vs. the other. Internal and external pilot studies are discussed, and recommendations for analyses of pilot studies are provided. A statement of caution (which is often repeated in the published literature) is provided: a pilot study should not be considered a “preliminary” test of the intervention (i.e., one should not report an imprecise treatment effect from an underpowered pilot trial as a conclusive statement of effectiveness); analyses undertaken within both pilot and feasibility studies should be mainly descriptive in nature and conclusions should reflect the objectives of this specific type of work. A list of potential factors to be examined in a pilot study is also provided.

NIH Pragmatic Trials Collaboratory - Pilot and Feasibility Testing: The LIRE Example (February 28, 2020): 18-min webinar (24-slide presentation; slides 23-46)

• Summary: Dr. Jeffrey Jarvik discusses pilot and feasibility testing in pragmatic trials. It is emphasized that “process issues” can often derail a pragmatic trial, and that pilot and feasibility studies will increase the likelihood of completing the full-scale trial in an efficient and scalable manner. In pilot and feasibility work for pragmatic trials, relevant partnerships (e.g., with healthcare system leaders), collaborations with technical personnel (e.g., statisticians, data analysts), and local champions at study sites, are essential. Aspects related to feasibility that can be pilot tested include e.g., routinely collected data-related requirements and validation, coordination of processes/logistics with local champions, testing of the training materials for frontline providers/staff, capabilities and readiness of partner healthcare systems, and ease of integration of the study into clinical workflows.

Chan CL, et al. Pilot and feasibility studies for pragmatic trials have unique considerations and areas of uncertainty. J Clin Epidemiol. 2021 Oct;138:102-114. (13-page paper)

• Summary: This study identifies ten relevant domains, partly based on PRECIS-2 tool, and describes potential questions of uncertainty within each: intervention development, research ethics, participant identification and eligibility, recruitment of individuals, setting, organization, flexibility of delivery, flexibility of adherence, follow-up, and importance of primary outcome to patients and decisionmakers. Examples are presented to illustrate how uncertainty in these domains might be examined within a feasibility study. 

Pilot & Feasibility - Randomized Controlled Trials. (2017). Department of Evaluation and Research Services - Fraser Health Authority (British Columbia, Canada): 35-slide presentation.

• Summary: Provides definitions of pilot and feasibility studies in the context of randomized trials and explores the differences between external vs. internal pilot trials. The reasons for conducting pilot and feasibility studies, and their underlying objectives, are compared, and advice for designing, analyzing, and reporting a pilot trial is provided.

Whitehead AL, et al. Pilot and feasibility studies: is there a difference from each other and from a randomised controlled trial? Contemp Clin Trials. 2014 May;38(1):130-3. (4-page paper) * As this is an optional resource, an institutional login (e.g., university or research institute e-mail address) is required to access this material. 

• Summary: The definitions of “feasibility” studies and “pilot” studies/trials are not clear cut, and many authors have redefined them over time. As such, the terms are often misused in the context of clinical (trials) research. From a review of the literature, the distinguishing features of a pilot study (vs. a feasibility study) were as follows: (1) Stricter study methodology (e.g., a justification of the sample size), (2) An intention for further work (otherwise, the pilot may be seen as an underpowered trial with limited scientific use), (3) Smaller version of the main study (e.g., with use of a control group and randomization), (4) A focus on a package processes. It is proposed that a pilot study is a special type of feasibility study (where the pilot work mimics processes of the envisioned definitive trial).