Key Features of Contemporary Pilot and Feasibility Trials: Protocol for a Methodological Study

Randomised clinical trials (RCTs) are costly undertakings requiring careful design, planning and conduct. Failure to achieve timely participant recruitment, separation between intervention groups and adequate follow-up contributes to waste in research. Pilot RCTs offer researchers the opportunity to examine whether a definitive trial may work as intended, for example, assessing whether the targeted sample size can be recruited, whether protocol adherence and between-group separation are achievable and whether outcome data can be collected. To maximise their value, more attention to the design, conduct and reporting of pilot RCTs is likely required. Here, we aim to describe and characterise feasibility assessment methodology in a cohort of contemporary pilot RCTs in hospitalised patients.

In this methodological study, we will describe key features of contemporary pilot RCTs in hospitalised patients across medical and surgical specialties. We will search for pilot/feasibility RCTs published within the last half calendar year, with the aim of including at least 100 RCTs assessing feasibility. If necessary to achieve the minimum sample, the search will be expanded to a maximum of 5 years. We will extract data on key trial characteristics (including area of care and type of intervention and comparator), whether feasibility was assessed and feasibility assessment methodology (feasibility areas assessed, conduct as stand-alone pilot, use of pre-defined outcomes and pre-specified criteria for progression to definitive RCT, adequacy of sample size justification, plans for definitive RCT, assessment of clinical outcomes and whether a definitive trial was deemed feasible). Findings will be summarised using descriptive statistics for all trials and stratified by intervention type, area of care and comparator type.

The outlined methodological study will provide data on key features of contemporary pilot RCTs in hospitalised patients, including the feasibility assessment methodologies employed. This may improve design, conduct and reporting of future pilot RCTs, ultimately increasing their value and reducing research waste.