Table 4 Pre-specified progression criteria with a traffic light system for decision making about proceeding to a full-size trial
N | Criteria | Measurement | Traffic light system for proceeding to a full-size trial | |||||
|---|---|---|---|---|---|---|---|---|
Green light: go—proceed | Amber light: amend—proceed with caution | Red light: stop—do not proceed | ||||||
Planned | Achieved | Planned | Achieved | Planned | Achieved | |||
1 | Recruitment | Number of participants recruited over a 6-month period | ≥ 24 | – | 23–12 | 12 | < 12 | – |
2 | Acceptability of recruitment procedures | Qualitative process evaluation | Most participants find acceptable or only minor amendments needed | 11 interviewees found procedures acceptable and suggested additional recruitment pathways. | Conflicting views or larger changes needed | – | Most participants find unacceptable | – |
3 | Acceptability of randomisation procedure | Qualitative process evaluation | Most participants find acceptable or only minor amendments needed | — | Conflicting views or larger changes needed | One interviewee suggested to clarify the procedure. Some participants felt that randomisation into NHS psychological support service was not appealing. | Most participants find unacceptable | – |
4 | Follow-up (total and by trial arms) | Proportion of enrolled participants who provided primary outcome data at 6 months post-randomisation (out of those randomised) | > 50% | 16/20 women (80%): intervention arm 13/15 (87%) control arm 3/5 (60%) | 31–50% | – | < 50% | – |
5 | Acceptability of follow-up procedure (total and by trial arms) | Qualitative process evaluation | Most participants find acceptable or only minor amendments needed | For some women the questions asked at follow-up could be triggering. | Conflicting views or larger changes needed | – | Most participants find unacceptable | – |
6 | Uptake of trauma-specific mindfulness-based cognitive therapy (intervention arm) | Proportion of participants who started the mindfulness group (out of those randomised to the intervention arm) | ≥ 70% | 11/15 (73%, 95% CI 44.9 to 92.2%) | 50–69% | – | < 50% | – |
7 | Retention in trauma-specific mindfulness-based cognitive therapy group (intervention arm) | Proportion of participants who received at least four sessions (out of those who started the group) | ≥ 60% | 11/11 (100%) | 40–59% | – | < 40% | – |
8 | Acceptability of trauma-specific mindfulness-based cognitive therapy (intervention arm) | Qualitative process evaluation | Most participants find acceptable or only minor amendments needed. | – | Conflicting views or larger changes needed | Interviewees suggested safety measures, amendments to course content, home practice. | Most participants find unacceptable | – |
9 | Acceptability of data collection methods | Qualitative process evaluation | Most participants find acceptable or only minor amendments needed | Most participants found data collection tools and procedures acceptable. | Conflicting views or larger changes needed | – | Most participants find unacceptable | – |