Clinical and cost-effectiveness of a personalised health promotion intervention enabling independence in older people with mild frailty ('HomeHealth') compared to treatment as usual: study protocol for a randomised controlled trial.

Background: Frailty is clinically associated with multiple adverse outcomes, including reduced quality of life and functioning, falls, hospitalisations, moves to long-term care and mortality. Health services commonly focus on the frailest, with highest levels of need. However, evidence suggests that frailty is likely to be more reversible in people who are less frail. Evidence is emerging on what interventions may help prevent or reduce frailty, such as resistance exercises and multi-component interventions, but few interventions are based on behaviour change theory. There is little evidence of cost-effectiveness. Previously, we co-designed a new behaviour change health promotion intervention ("HomeHealth") to support people with mild frailty. HomeHealth is delivered by trained voluntary sector support workers over six months who support older people to work on self-identified goals to maintain their independence, such as strength and balance exercises, nutrition, mood and enhancing social engagement. The service was well received in our feasibility randomised controlled trial and showed promising effects upon outcomes.

Aim: To test the clinical and cost-effectiveness of the HomeHealth intervention on maintaining independence in older people with mild frailty in comparison to treatment as usual (TAU).

Methods: Single-blind individually randomised controlled trial comparing the HomeHealth intervention to TAU. We will recruit 386 participants from general practices and the community across three English regions. Participants are included if they are community-dwelling, aged 65 + , with mild frailty according to the Clinical Frailty Scale. Participants will be randomised 1:1 to receive HomeHealth or TAU for 6 months. The primary outcome is independence in activities of daily living (modified Barthel Index) at 12 months. Secondary outcomes include instrumental activities of daily living, quality of life, frailty, wellbeing, psychological distress, loneliness, cognition, capability, falls, carer burden, service use, costs and mortality. Outcomes will be analysed using linear mixed models, controlling for baseline Barthel score and site. A health economic analysis and embedded mixed-methods process evaluation will be conducted.

Discussion: This trial will provide definitive evidence on the effectiveness and cost-effectiveness of a home-based, individualised intervention to maintain independence in older people with mild frailty in comparison to TAU, that could be implemented at scale if effective.

Trial Registration: ISRCTN, ISRCTN54268283 . Registered 06/04/2020.