Clinical and cost-effectiveness of a personalised health promotion intervention enabling independence in older people with mild frailty (‘HomeHealth’): A Randomised Controlled Trial

Background: Addressing complex needs in older people is challenging for NHS and social care. Current services focus on those with highest levels of need/frailty, but can be expensive, with mixed outcomes. We know little on clinically and cost-effective interventions for people with mild frailty. Aim: To test clinical and cost-effectiveness of the HomeHealth intervention on maintaining independence in older people with mild frailty. Design: Single-blind individually randomised controlled trial of the HomeHealth intervention compared to Treatment As Usual (TAU). Embedded process evaluation. Setting: General Practices in diverse areas of London, Yorkshire & Hertfordshire. Target population: Older people 65+ years with mild frailty defined using the Clinical Frailty Scale. Exclusion criteria: Those in care homes, receiving palliative care, who lack capacity, already case-managed (e.g. by community teams). HomeHealth Intervention: Theory/evidence-based co-designed behaviour change health promotion intervention, supporting older people to work on goals to maintain independence, addressing factors (e.g. weakness) impacting on capability, opportunity and motivation. This includes physical activity/balance and strength exercises, nutrition, mood and enabling social engagement, individually tailored. Outcomes: Primary: Functioning Activities of Daily Living (modified Barthel Index (BI)). Secondary: Instrumental Activities of Daily Living; quality of life; frailty phenotype (gait speed, grip strength, physical activity, exhaustion, weight loss/low BMI); wellbeing; psychological distress; loneliness; falls; cognition; capability; service use; costs; mortality. Sample size: To detect a 1.85 point difference on the BI at 12 months with 90% power and 5% significance, assuming a SD of 5 and 20% attrition, total sample size is 386. Analysis: The primary outcome will be analysed by intention-to-treat using mixed effects linear regression, with a random effect for therapist and controlling for baseline BI score. Secondary outcomes will be analysed with analogous linear or logistic regressions. Economic analysis: We will calculate mean incremental cost per quality adjusted life year and years full of capability gained for the duration of the trial and report this from perspectives of the NHS, personal and social care services. A budget impact analysis will quantify costs to health and social care providers. Process evaluation: We will undertake a mixed-methods process evaluation exploring fidelity, dose and reach of the intervention, potential mechanisms, contextual factors and pathways to impact. This includes semi-structured interviews (n~40) with a purposive sample of participants, service providers and stakeholders, using normalisation process theory to understand implementation and barriers and facilitators. Interviews will be recorded, transcribed and thematically analysed. We will assess fidelity from audio-recordings of intervention appointments and explore mechanisms/pathways to impact including goals selected, goal attainment, intervention effects stratified by behavioural target(s) and impact on behavioural outcomes. Impact: This will test a new proactive health promotion service for older people with mild frailty. Our approach is designed to enable rapid implementation within diverse settings.