P1056How does a digital self-management programme lead to improvements in quality of life in inflammatory bowel disease? Mediation analysis of Cognitive, Behavioural and Emotional Pathways.

Abstract Background Around 50% of people with inflammatory bowel disease (IBD) continue to experience pain, fatigue, and/or faecal urgency during clinical remission. The IBDBOOST digital selfmanagement programme, based on a cognitive behavioural model of symptom perpetuation, was designed to target cognitive, behavioural, and emotional factors hypothesised to maintain these symptoms. The IBD-BOOST randomised controlled trial (RCT) showed no significant betweengroup (intervention vs treatment as usual) differences in IBDrelated quality of life (QoL) at six months), although IBD-BOOST was costeffective, and complier-average causal effect analyses suggested benefits for adherent participants. This study tested the theoretical model by examining whether changes in negative illness perceptions, selfefficacy, behavioural responses to symptoms, depression, and IBDspecific anxiety mediated the intervention’s effect on QoL. Methods Adults (n = 780) with IBD experiencing pain, fatigue, and/or urgency/incontinence were randomised to IBD-BOOST(n = 391) or CAU (n = 389). Primary outcome was IBDrelated QoL (UKIBDQ) at six months. Singlemediator hierarchical regression models were fitted for cognitive (illness perceptions, selfefficacy), behavioural (allornothing, avoidance/resting), and emotional (depression, IBDspecific anxiety) variables, adjusting for baseline mediator and outcome, demographics, and disease characteristics. Indirect effects were estimated using the productofcoefficients method with bootstrap 95%CIs. Results The intervention had no total effect on QoL at six months (estimate=0.13, 95%CI 0.22 to 0.01). However, indirect effects on QoL were observed via: Illness perceptions (estimate=0.09, 95%CI 0.14 to 0.04), Selfefficacy (estimate=0.15, 95%CI 0.21 to 0.09, Allornothing behaviour (estimate =0.04, 95%CI 0.06 to 0.01), Avoidance/resting behaviour (estimate =0.08, 95%CI 0.12 to 0.04) and IBDspecific anxiety (estimate =0.15, 95%CI 0.20 to 0.11), but not depression. Conclusion Improvements in IBD QoL were explained in part by changes in the IBD-BOOST targeted mechanisms. These findings support the theoretical model underpinning the intervention and highlight the importance of addressing cognitive, behavioural, and emotional processes in symptomfocused selfmanagement for IBD. Future work should explore strategies to optimise engagement and maximise these mediating effects. Conflict of interest: Dr. Wileman, Vari: No conflict of interest Cléirigh Büttner, Fionn: No conflict of interest Goldsmith, Kimberley: No conflict of interest Norton, Christine: Personal Fees: Janssen: lecture fee WebMD lecture fee Medscape symposium fee Merck Pharmaceuticals lecture fee Pfizer advisory board fee Hamborg, Thomas: No conflict of interest Moss-Morris, Rona: RMM is a beneficiary of a licence agreement signed between King’s College London and Mahana Therapeutics for a digital cognitive behavioural therapy for an irritable bowel syndrome product. RMM receives personal fees from Mahana Therapeutics for scientific advisory work and from other universities and hospital trusts for cognitive behavioural therapy training in irritable bowel syndrome.