Statistical analysis plans for two randomised controlled trials of the Narrative Experiences Online (NEON) Intervention: impact of receiving recorded mental health recovery narratives on quality of life in people experiencing psychosis (NEON) and people experiencing non-psychosis mental health problems (NEON-O).

BACKGROUND: Mental health recovery narratives are a first-hand account of an individual's recovery from mental health distress, access to narratives can aid recovery. The NEON Intervention is a web-application providing access to a managed collection of narratives. We present the statistical analysis plan for assessing the effectiveness of the NEON Intervention in improving quality of life at 1-year post-randomisation. We pay particular focus on the statistical challenges encountered due to the online nature of this trial.

METHODS AND DESIGN: The NEON Intervention is assessed in two trial populations, one for people with experience of psychosis in the last 5 years, and mental health distress in the last six months (NEON Trial) and one for people with experience of non-psychosis mental health problems (NEON-O Trial). Both NEON trials are two-arm randomised controlled superiority trials comparing the effectiveness of the NEON Intervention with usual care. The target sample size is 684 randomised participants for NEON and 994 for NEON-O. Participants were randomised centrally in a 1:1 ratio.

RESULTS: The primary outcome is the mean score of subjective items on the Manchester Short Assessment of Quality-of-Life questionnaire (MANSA) at 52 weeks. Secondary outcomes are scores from the Herth Hope Index, Mental Health Confidence Scale, Meaning of Life questionnaire, CORE-10 questionnaire and Euroqol 5-Dimension 5-Level (EQ-5D-5L).

CONCLUSION: This manuscript is the statistical analysis plan (SAP) for the NEON trials. Any post hoc analysis, such as those requested by journal reviewers will be clearly labelled as such in the final trial reporting. Trial registration Both trials were prospectively registered. NEON Trial: ISRCTN11152837, registered on 13 August 2018. NEON-O Trial: ISRCTN63197153, registered on 9 January 2020.