Process evaluation of the flucare cluster randomised controlled trial: assessing the implementation of a behaviour change intervention to increase influenza vaccination uptake among care home staff in England

Abstract Background Influenza (flu) vaccination rates of Care home staff (CHS) in England are consistently lower (≈ 15% in 2023) than World Health Organisation recommendations (≥ 75%). The FluCare trial examined the effectiveness of a multi-component intervention (including on-site flu vaccination clinics, information materials including video, £850 incentive and monthly monitoring with feedback) designed to address known barriers to flu vaccine uptake amongst CHS. This paper reports an embedded process evaluation designed to understand implementation of the FluCare intervention and provide explanations for observed effects in the trial. Methods The FluCare cluster randomised controlled trial was conducted between November 2022 and March 2023. A mixed methods process evaluation was conducted employing questionnaires, semi-structured interviews, video analytics (no. clicks and duration of view) and clinic logs (no. clinics delivered, days/time clinics were delivered, and no. staff vaccinated). CHS (including managers) and vaccination providers (pha