Table 1 Summary of considerations for implementation feasibility and pilot studies [18, 48,49,50]

Aims

To assess or describe contextual and environmental factors in order to inform the development of an implementation strategy.

To test the potential impact of an implementation strategy.

To assess or describe the feasibility, utility, acceptability or quality of trial methods.

Design

Formative, non-comparative designs. Focus usually on qualitative or mixed methods approaches.

Stand-alone study or as part of a Hybrid Type 1 design.

Summative and formative. Focus on comparative quantitative designs such as randomised or cluster randomised designs

Stand-alone study or as part of a Hybrid Type 2 design.

Summative and formative Focus may be quantitative, qualitative or mixed methods approaches.

Stand-alone study or as part of a Hybrid type 1 or 2 trial.

Measures

Measures informing design or development of implementation strategy such as context, acceptability, adaptability, feasibility, compatibility, cost, culture, dose, complexity and self-efficacy.

Measures of impact of implementation such as adoption, reach, fidelity and sustainability along with measures as per non-pilot implementation studies.

Measures informing implementation trial methods including the feasibility, acceptability or quality of data collection procedures, survey items, tools, or data management strategies.

Sample size and power

Justification of sample size based on achieving estimates of sufficient precision.

Justification of sample size based on achieving estimates of sufficient precision to inform trial progression (using progression criteria).

Justification of sample size based on achieving estimates of sufficient precision—which may or may not be linked to progression criteria.

Progression Criteria

Not required given such studies are formative.

Progression criteria set a priori based estimates of potential effects. Progression may be considered in conjunction with measures feasibility, acceptability or quality of methods (or other factors).

Progression criteria may be set a priori in summative pilot trials assessing trial methods. Progression may be considered in conjunction with estimates of potential trial effects (or other factors).

Reporting

Draw on relevant aspects of CONSORT extension for randomised pilot and feasibility trials, STaRi and reporting guidelines specific to the research design (e.g. STROBE)

Draw on upon existing reporting standards such as CONSORT extension for randomised pilot and feasibility trials, STaRi guidelines and TIDieR.

Draw on upon existing reporting standards such as CONSORT extension for randomised pilot and feasibility trials, STaRi guidelines and reporting guidelines specific to the research design.