Table 2 List of identified items for study-level feasibility assessment of clinical trials

1. Regulation, review and oversight

The clinical trial is compliant with local regulations

7 [5, 17,18,19, 21, 23, 25]

The study protocol has been (independently) peer reviewed

2 [21, 23]

Safety aspects are accommodated

3 [20, 21, 23]

2. Participant recruitment

The target population is available

8 [5, 17, 18, 20,21,22,23, 25]

Competing trials are known

7 [5, 17, 18, 21, 23,24,25]

A recruitment rate is estimated

6 [18, 19, 21,22,23,24]

Factors that hinder/have an impact on recruitment are known

5 [5, 21, 23,24,25]

The target sample size to recruit is known

5 [5, 18, 19, 21, 22]

The study is interesting to others (e.g. physicians, co-investigators)

5 [5, 18, 20, 21, 24]

Strategies and resources that are needed for recruitment are known

4 [5, 17, 21, 24]

Routine data sources corroborate estimated recruitment rate or can facilitate recruitment

4 [5, 17, 23, 24]

Eligibility criteria are clear and realistic

3 [17, 18, 25]

Other sites are available, if necessary

3 [17, 24, 25]

Organisations and groups, relevant to recruitment, are known

2 [5, 24]

How the target sample size was calculated is known

2 [5, 21]

The necessary number of sites is known

2 [17, 19]

The estimated recruitment rate(s) is/are reasonable

1 [23]

3. Space, material and equipment

Access to professional support and required facilities is available

8 [5, 17,18,19, 21, 22, 24, 25]

Equipment is appropriate and sufficient

8 [5, 17,18,19,20, 22, 24, 25]

Working space is appropriate and sufficient to conduct the study

6 [5, 17, 19, 21, 24, 25]

Study drug and comparator are available

7 [17,18,19,20,21, 24, 25]

Storage room for study material is appropriate and sufficient

5 [5, 17, 19, 21, 25]

Secure storage room for study or patient documents/ recorded data is sufficient

6 [5, 17, 19,20,21, 25]

Access to relevant electronic systems are available

5 [5, 18,19,20,21]

4. Financial resources

The budget is adequate

6 [17, 18, 20, 21, 23, 25]

Excess costs at sites are accommodated

3 [5, 21, 24]

The budget for recruitment and follow-up visits is adequate

1 [19]

5. Trial team resources

Adequate staffing is identified and available within the trial period

8 [5, 17,18,19,20,21, 24, 25]

Investigator / study team has time for study visits

5 [5, 17, 20, 21, 24, 25]

Investigator has time to complete the study

4 [5, 21, 24, 25]

Training for staff is available

4 [5, 18, 21, 24]

Investigator has appropriate experience

3 [21, 24, 25]

Investigator has time to supervise the trial team

4 [17, 20, 24, 25]

Investigator has time to check the data

2 [17, 25]

Investigator has time to interact with the sponsor

2 [17, 25]

Work out of hours is accommodated

2 [5, 21]

Investigator has capacity to recruit the patients

1 [25]

6. Trial management

Current standard of practice at trial site is compatible with trial protocol

8 [5, 17, 18, 20,21,22,23,24]

The study schedule is reasonable

4 [17, 18, 22, 25]

Specific patient related aspects are accommodated (e.g. children)

3 [21, 23, 24]

The methods for site selection are known

3 [5, 20, 24]

Project management considerations were made

2 [5, 19]

Special vendor requirements are known

2 [18, 21]

On-site management is available

1[19]

Clinical care for trial participants is coordinated and managed

1 [24]

Assessment of outcomes is accommodated at sites

1 [24]

7. Pilot or feasibility studies

A pilot study was conducted

2 [5, 24]

All sites were included in the feasibility studies

1 [24]