Table 1 OPTIMA RCT internal pilot progression rules

Recruitment

 Green: > 70% of recruitment target for that period.

 Amber: 50–70%. A lower rate would be also acceptable, if there is evidence of an upward recruitment trajectory and/or a clear plan for further improvement (e.g. new sites, or ways of recruiting).

 Red: < 50% and no evidence of an upward trajectory.

Intervention engagement

 Green: > 90% of participants providing primary outcome data at primary endpoint (3 months post-randomisation) will have engaged with the two first modules of the intervention.

 Amber: 60–90%. A lower rate also acceptable if there is evidence of improvement or/and a clear plan for improving engagement.

 Red: < 60% and no evidence of improvement.

Attrition

 Green: > 75% of participants who have reached the relevant time window will have completed primary endpoint assessments to provide primary outcome data.

 Amber: 50–75%. A lower rate is acceptable if there is evidence of improving retention and/or a clear plan for enhancing retention.

 Red: <50% and no evidence of improving retention.