Process evaluation of a health coaching and social prescribing intervention to support adults with HIV in England: qualitative analysis of service providers’ perspectives on the implementation of the trial protocol

Background Health and wellbeing coaching supports people to set goals and motivates behaviour change to improve health and quality of life outcomes. The SPHERE trial aimed to test the effectiveness of a health and wellbeing coaching and social prescribing intervention in improving the health and wellbeing of people with HIV with unmet psychosocial need. In this intervention, HIV health care professionals were trained as health and wellbeing coaches. We explore the factors that promoted or inhibited the implementation of trial processes from the perspective of service providers. Methods A process evaluation of SPHERE involving semi-structured interviews with 24 service providers involved in the trial across seven HIV clinics in England. Interviews were conducted in two phases: (i) first three sites open for recruitment (October–December 2024) and (ii) main phase with all sites (April–August 2025). Topic guides were shaped by Normalisation Process Theory (NPT) constructs. Data were analysed using inductive and deductive coding guided by qualitative content analysis, abductive approaches and mapped to NPT constructs. Results Intervention components, strategies and organising logic promoted the implementation of trial processes. Health coaching training and supervision was viewed as a significant enabler for trial feasibility. Inhibitors to implementation centred around trial rules and resources particularly staffing capacity (workforce), workload and workflow. Social prescribing had mixed engagement and was fragmented in terms of communications and delivery. Conclusions Health and wellbeing coaching is a personalised approach which could improve mental and physical health outcomes and address psychosocial needs in people with long term conditions. Existing clinic capacity, resources and staff roles need to be considered when implementing coaching interventions which should also offer flexibility to ensure equitable reach and access. Trial registration ISRCTN47187932 (registered 12 July 2024).