Statistical methods for primary and secondary outcomes 
SECONDARY
Outcome analyses will be performed by a dedicated biostatistician. An intention-to-treat analysis will be performed on all randomised patients and a per-protocol analysis will be performed on all patients who complete the study. Descriptive statistics will be calculated for all outcome measures at each time point. Continuous variables will be reported using means, medians, standard deviations and score ranges. Categorical variables will be described using frequencies and percentages.Descriptive and inferential statistics will be obtained using the appropriate statistical methods that seek to address our identified objectives. The primary analysis will compare the effect of the interventions on the primary outcome; distress levels at 12 weeks post-completion of the intervention period (i.e. c18 weeks post-baseline). All outcome analyses will be conducted according to an intention-to-treat principle, i.e. all randomised participants will be included in the main analysis and will be analysed as randomised, regardless of protocol adherence. Secondary analysis will include the analysis of the primary outcome post-intervention and analysis of the secondary and treatment process outcomes detailed previously post-intervention and at the 12-week follow-up. Linear mixed models on the outcome measures over time will be fitted to evaluate the effect of both study conditions, which intrinsically adjusts for baseline scores.Statistical significance will be assessed from a 