A group-based exercise and behavioural maintenance intervention for adults over 65 years with mobility limitations: the REACT RCT
Authors: Stathi Afroditi , Withall Janet , Greaves Colin J , Thompson Janice L , Taylor Gordon , Medina-Lara Antonieta , Green Colin , Snowsill Tristan , Johansen-Berg Heidi , Bilzon James , Gray Selena , Cross Rosina , Western Max J , Koning Jolanthe L de , Ladlow Peter , Bollen Jessica C , Moorlock Sarah J , Guralnik Jack M , Rejeski W Jack , Hillsdon Melvyn , Fox Kenneth R 
Published: December 2022

Background
Mobility limitation in older age reduces quality of life, generates substantial health- and social-care costs, and increases mortality.

Objective
The REtirement in ACTion (REACT) trial aimed to establish whether or not a community-based active ageing intervention could prevent decline in physical functioning in older adults already at increased risk of mobility limitation.

Design
A multicentre, pragmatic, two-arm, parallel-group randomised controlled trial with parallel process and health economic evaluations.

Setting
Urban and semi-rural locations across three sites in England.

Participants
Physically frail or pre-frail older adults (aged ≥ 65 years; Short Physical Performance Battery score of 4–9). Recruitment was primarily via 35 primary care practices.

Interventions
Participants were randomly assigned to receive brief advice (three healthy ageing education sessions) or a 12-month, group-based, multimodal exercise and behavioural maintenance programme delivered in fitness and community centres. Randomisation was stratified by site and used a minimisation algorithm to balance age, sex and Short Physical Performance Battery score. Data collection and analyses were blinded.

Main outcome measures
The primary outcome was change in lower limb physical function (Short Physical Performance Battery score) at 24 months, analysed using an intention-to-treat analysis. The economic evaluation adopted the NHS and Personal Social Services perspective.

Results
Between June 2016 and October 2017, 777 participants (mean age 77.6 years, standard deviation 6.8 years; 66% female; mean Short Physical Performance Battery score 7.37, standard deviation 1.56) were randomised to the intervention arm (n = 410) or the control arm (n = 367). Data collection was completed in October 2019. Primary outcome data at 24 months were provided by 628 (80.8%) participants. At the 24-month follow-up, the Short Physical Performance Battery score was significantly greater in the intervention arm (mean 8.08, standard deviation 2.87) than in the control arm (mean 7.59, standard deviation 2.61), with an adjusted mean difference of 0.49 (95% confidence interval 0.06 to 0.92). The difference in lower limb function between intervention and control participants was clinically meaningful at both 12 and 24 months. Self-reported physical activity significantly increased in the intervention arm compared with the control arm, but this change was not observed in device-based physical activity data collected during the trial. One adverse event was related to the intervention. Attrition rates were low (19% at 24 months) and adherence was high. Engagement with the REACT intervention was associated with positive changes in exercise competence, relatedness and enjoyment and perceived physical, social and mental well-being benefits. The intervention plus usual care was cost-effective compared with care alone over the 2 years of REACT; the price year was 2019. In the base-case scenario, the intervention saved £103 per participant, with a quality-adjusted life-year gain of 0.04 (95% confidence interval 0.006 to 0.074) within the 2-year trial window. Lifetime horizon modelling estimated that further cost savings and quality-adjusted life-year gains were accrued up to 15 years post randomisation.

Conclusion
A relatively low-resource, 1-year multimodal exercise and behavioural maintenance intervention can help older adults to retain physical functioning over a 24-month period. The results indicate that the well-established trajectory of declining physical functioning in older age is modifiable.

Limitations
Participants were not blinded to study arm allocation. However, the primary outcome was independently assessed by blinded data collectors. The secondary outcome analyses were exploratory, with no adjustment for multiple testing, and should be interpreted accordingly.

Future work
Following refinements guided by the process evaluation findings, the REACT intervention is suitable for large-scale implementation. Further research will optimise implementation of REACT at scale.

Trial registration
This trial is registered as ISRCTN45627165.

Funding
This project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 10, No. 14. See the NIHR Journals Library website for further project information.