Table 4 Summary of progression criteria

PC1. Feasibility to recruit a sufficient proportion of new NERS patients to participate in the trial, with appropriate retention rates to 12-month follow-up.

• The percentage of new NERS patients recruited to the trial, and retained at each subsequent follow-up.

• Regression models will be used to identify predictors of loss to follow-up (e.g. demographics or baseline motivation).

• If > 20% of new NERS patients recruited = proceed; if < 5% = full-scale trial unlikely to be feasible. If 5–20% the TSC will consider the feasibility of proceeding to a full-scale trial bearing in mind the data and feedback presented and representativeness of the recruited sample, and possible steps to increase the recruitment rate.

• If > 80% retained at 12-months = proceed, if < 60% = full-scale trial unlikely to be feasible. If 60–80% the TSC will consider the feasibility of proceeding based on the available data and possible steps to increase retention.

PC2. Intervention and trial methodology delivered as intended

• Summary statistics for intervention fidelity measures overall and by area.

• Compliance with study invite processes.

• Compliance with randomisation processes.

• The TSC will consider the data presented and make a judgement about whether the intervention and trial methodology were delivered as intended.

PC3. At least one of the two intervention components is acceptable to participants

• Percentages of participants who report acceptability of the intervention components on four self-report questions.

• Issues regarding acceptability of, and engagement with, the two intervention components explored in qualitative interviews with a sub-sample of intervention participants.

• The TSC will consider the quantitative and qualitative data and make an overall judgement on whether the intervention is acceptable.

PC4. Recruitment and randomisation processes acceptable to > 50% of recruited participants

• Percentages of participants who report acceptability of the recruitment and randomisation processes on patient questionnaires.

• Exploration of understanding and acceptability of recruitment and randomisation processes in qualitative interviews.

• > 50% of recruited participants report ‘agree’ or ‘strongly agree’ to questions about the acceptability of recruitment and randomisation processes.

• The TSC will apply discretion in judging whether this criterion has been met, or could be addressed to improve acceptability in a full-scale trial.

PC5. < 20% of control group exposed to the intervention components

• The percentage of participants in intervention and control groups who report that they were provided with a MWK device or accessed the MWC web platform.

• < 20% of control participants report that they have used a MWK device during the study period.

• < 20% of control participants report that they have accessed the MWC during the study period.