FluCare: Estimating the effectiveness and cost-effectiveness of a complex intervention to increase care home staff influenza vaccination rates

Background Seasonal influenza (flu) causes thousands of deaths each year in the UK, creating a major risk for care home residents. Whilst the World Health Organisation recommends 75% of social care staff are vaccinated, only 25-40% do so. With a need for tailored interventions, we used the Theoretical Domains Framework (TDF) to create a complex intervention consisting of regular in-care home staff vaccination clinics run by the supplying community pharmacy, free vaccination for all staff, theoretically underpinned information for staff, financial incentives for homes achieving vaccination rates over 70% and regular care home performance monitoring/feedback. Aim To estimate the effectiveness and cost-effectiveness of our complex intervention designed to increase staff flu vaccination rates in care homes for older adults. Method A public and patient involvement advisory group will contribute throughout the project. The project management team, expert advisory panel, trial steering and data management committees will meet regularly, overseeing project delivery. The TDF and Behaviour Change Wheel will underpin individual phases. Phase 1: Intervention finalisation (months 1-2) Intervention components and implementation strategies (e.g. information material production) and trial procedures (e.g. data collection methods, fidelity framework and Mechanisms of Action questionnaire) will be finalised. Phase 2: Feasibility study (months 2-11) 10 purposively selected homes will be allocated to receive the full intervention (2), usual care (2) or different parts of the intervention (3x2) to identify which parts, if any, maximise data quality and minimise bias. Within this we will test and refine methods for collecting outcome data, home/staff/resident characteristics and intervention costs. To understand how organisational context shapes intervention delivery, describe intervention fidelity and acceptability and identify sources of contamination between arms, we will use questionnaires, ethnographic visits, up to 40 interviews and documentary review. Phase 3: Definitive trial (months 8-28) 70 recruited homes and pharmacies will be randomised to intervention or control. This will provide 90% power at a 5% significance level for detecting an increase in staff vaccination rate from 55% to 75%. A process evaluation will be undertaken to assess intervention fidelity; control arm contamination, any reactivity bias; to enable us to explain trial results and generate recommendations for wide-scale implementation. A cost-consequences analysis comparing costs and outcomes across trial arms for different stakeholders (e.g. care homes, NHS and staff) will be undertaken. The cost per percentage point increase in vaccination rate will be estimated. Phase 4: Policy development for dissemination (months 24-32) The TDF and Behaviour Change Wheel will inform our dissemination strategy. We will conduct three stakeholder workshops to identify how to deliver wide-scale intervention implementation in homes. Our policy group will develop and disseminate implementation guidance. Impact Higher care home staff flu vaccination rates and improved resident health.