Scientific summary

Research Question:

What is the effectiveness and cost-effectiveness, compared with a minimal intervention control condition, of a community-based physical activity intervention (REACT) for reducing the progression of functional limitations in older people who are at high risk of mobility-related disability?


Modelled on the LIFE physical activity intervention for older people in the US, REACT was a standardised 12-month, primarily group-based physical activity programme with two phases:


1) Adoption (weeks 1 24) provided a 45-minute individual assessment, followed by two 60 minute sessions per week designed to stimulate initial increases in fitness, lower-limb function, confidence and social support and facilitate lifestyle changes;


2) Maintenance (weeks 25-52) provided an optional weekly exercise session. Participants were informed about local activity opportunities, offered taster session vouchers for various activities, and invited to become REACT Ambassadors to support the ongoing sustainability of REACT. The setting: Leisure/community centres and fitness/health clubs provided by REACT collaborators during low usage hours in economically and ethnically diverse areas.


Delivery staff:

Qualified exercise specialists were trained to deliver the intervention.

Funding: Intervention costs were covered by BANES City Council, the West Bank Charitable Organisation and AgeUK Birmingham.


Evaluation methods:

A multi-centre pragmatic two-arm parallel group randomised controlled trial with an internal pilot phase, and a 24 month follow-up, comparing REACT with a minimal intervention control condition.


Participants: 777 sedentary men and women aged 65+ who were at risk of major mobility limitations but who were still ambulatory, were randomised in a 1:1 ratio to either intervention or control group. Control participants received a minimal intervention comprising three education sessions on healthy ageing (non-physical activity related).



The primary outcome was functional ability (independently assessed performance on a sit-to-stand task, a standing balance test and gait speed), measured using the Short Physical Performance Battery (SPPB) at 24 months.


The secondary outcome was minutes of moderate intensity physical activity, assessed by accelerometry.


Tertiary outcomes included minutes of sedentary behaviour, health-related quality of life, cognitive function, mental well-being and the Barthel Index (an indicator of ability to live independently).


Health economics:

A full economic evaluation was conducted to estimate the incremental cost-effectiveness of the REACT intervention compared with the control condition. Decision-analytic modelling assessed cost-effectiveness over a lifetime perspective.



Using intention-to-treat analysis of variance, the REACT intervention groups and the control groups were compared at 24 months presented as between-group mean differences, 95% confidence intervals and p-values.

Public health impact:

Evidence-based, cost-effective interventions for preventing mobility disability in older people and tackling inactivity are needed to reduce health risks, particularly among people with low socio-economic status. Drawing on the latest, evidence-based intervention technology from the US and translating this for use in the UK has the potential to provide a timely response to this urgent problem.

To view the full scientific protocol click here.