Table 5 An overview of the eight red flags identified in trial managers’ correct predictions of a failure to recruit to target

1

Previous poor performance

2

Slow/non-standard approval process

3

Patient or staff preferences or beliefs

4

Target for recruitment

5

Problems with the trial protocol and/or its implementation

6

Lack of engagement of site team

7

Lack of research experience of site staff/staff changes

8

Busy site staff