The effectiveness and cost-effectiveness of a peer-volunteering active ageing programme in preventing mobility decline in older adults

INTERVENTION: The ACE study is an individually randomised, parallel‐group, single‐blind randomised controlled trial with an internal pilot phase, a whole‐systems oriented process evaluation and an economic evaluation. Participants, who will be 65 years old or older, will mainly be recruited via a letter of invitation from their GPs. 515 patients who meet the study inclusion criteria will be randomised to receive either the ACE intervention, delivered over a period of 6 months by peer volunteers, or a minimal control intervention. Peer volunteers will be recruited and managed by volunteering organisations such as the Royal Volunteering Service. ACE is a low‐cost programme where older volunteers (55 years +) support older people (65 years +) to improve their mobility by becoming more active within their communities. The 515 older people recruited to the study will be sedentary and community living, with functional limitations (i.e. who are at risk of major mobility limitations), but who can still walk independently (including with a walking stick). This will be measured using a physical function test to assess balance, walking speed and the ability to go from a sitting to a standing position. The researchers are targeting a non‐disabled, but at‐risk population. During the ACE programme, volunteers (n=150) will meet with participants twice to get to know each other, find out about and discuss local community‐based activities that the participant would like to join, and identify and address any barriers to taking part (weeks 1 and 2). Then, over a 3‐month period, the volunteer‐participant pair will attend at least three local activities chosen by the participant, together. Over the following 3 months volunteers will supp CONDITION: Physical function in older people at risk of mobility disability ; Not Applicable PRIMARY OUTCOME: Lower limb physical function assessed using a Short Physical Performance Battery (SPPB) at baseline, 6 and 18 months SECONDARY OUTCOME: ; Participants and volunteers:; 1. Weekly volume of physical activity accounting for both physical activity intensity and duration, measured using accelerometry at baseline, 6, 12 and 18 months; 2. Average number of times a participant transitions from sitting to standing per hour of the day, measured using accelerometry at baseline, 6, 12 and 18 months; 3. The number of times a participant transitions from sitting to standing each hour of the day, measured using accelerometry at baseline, 6, 12 and 18 months; 4. Average proportion of each waking hour spent in active events, measured using accelerometry at baseline, 6, 12 and 18 months; 5. Average proportion of each waking hour spent inactive, measured using accelerometry at baseline, 6, 12 and 18 months; 6. Adherence to Chief Medical Officers’ recommendations for strength training exercise measured using Muscle‐Strengthening Exercise ‐ Adherence scale at baseline, 6 and 18 months; 7. Psychological functioning and well‐being measured using the Warwick‐Edinburgh Mental Well‐being Scale (WEMWBS) at baseline, 6, 12 and 18 months; 8. Subjective well‐being measured using the Ageing‐Well Profile at baseline, 6 and 18 months; ; Participants only:; 1. Health‐related quality of life measured using EQ‐5D‐5L, ICECAP‐O at baseline, 6, 12 and 18 months; 2. Capability measured using ICECAP‐O at baseline, 6, 12 and 18 months; 3. Activities of daily living measured using EQ‐5D‐5L, ICECAP‐O at baseline, 6, 12 and 18 months; 4. Medical history, medications, health and social service usage measured using medical history and medications, health and social care usage questionnaires at baseline, 6, 12 and 18 months; 5. Frequency of trips out of the house measured using a questionnaire item on trips out of the house (previously used in the OPAL study) at baseline, 6 and 18 months; 6. Frequency of falls, injurious falls and fear of falling measured using Falls Inventory, Short Falls‐Efficacy scale‐international (Short FES‐I) at baseline, 6 and 18 months; 7. Pain measured using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline, 6 and 18 months; 8. Progression of frailty assessed using the Fried Frailty Phenotype score at baseline, 6 and 18 months, including the following components:; 8.1. Grip strength in kg (highest score out of three trials), measured using a dynamometer; 8.2. Gait speed (4 m walk from Short Physical Performance Battery); 8.3. Physical activity measured using the International Physical Activity Questionnaire‐Elderly (PASE) (9); 8.4. Exhaustion measured using exhaustion questions from the Centre for Epidemiological Studies Depression Scale; 8.5. Unintentional weight loss; 9. Cognitive function measured using the Montreal Cognitive Assessment (MoCA) at baseline, 6 and 18 months; 10. Loneliness measured using the 3‐item Revised UCLA loneliness scale at baseline, 6, 12 and 18 months; 11. Social networks assessed using Lubben's Social Network Scale at baseline, 6, 12 and 18 months; ; Peer volunteers only:; 1. Motivation to volunteer and volunteering outcomes measured using Short Volunteer Functions Inventory at baseline, 6 and 18 months; 2. Amount of intervention‐related contact between participants and volunteers measured using diary of contacts with ACE participant(s) at 6 months; ; Process evaluation measures:; 1. Motivation to adhere to the CMO recommendations for strength training measured using Muscle‐Strengthening Exercise ‐ Perceived importance (single‐item) and confidence (single item) scales at baseline, 6, 12 and 18 months; 2. Motivation (based on the satisfaction of basic human needs (competence, autonomy and relatedness) to adhere to the CMO recommendations for aerobic activity measured using the aerobic activity perceived confidence, autonomy, and relatedness scale at baseline, 6, 12 and 18 months; 3. Motivation (based on the satisfaction of basic human needs (competence, autonomy and relatedness) to participate in community activities measured using Community activities ‐ Perceived confidence, autonomy, and relatedness scale at baseline, 6, 12 and 18 months; 4. Perceived benefits of participation in aerobic activity measured using Physical activity – Perceived Benefits scale at baseline, 6, 12 and 18 months; 5. Perceived benefits of participation in community activities measured using the Community Activity Perceived Benefits scale at baseline, 6, 12 and 18 months; 6. Evaluation of natural and built local environment characteristics measured using the Quality of the Local Community scale at baseline, 6, 12 and 18 months; 7. Feedback on the ACE programme (intervention group only) collected using qualitative interviews and group discussions at 6 months; 8. Engagement in local community activities using the activities in the local community scale (3 items) collected at 6,12, and 18 months; 9. Intervention fidelity/quality of intervention delivery assessed by applying a checklist to a purposive sample of audio‐recordings of intervention contacts between the volunteer and the participant collected at 6 months; INCLUSION CRITERIA: 1. Short Physical Performance Battery (SPPB) score between 4 and 9 inclusive. This is based on definitions of physical frailty from the European Medicines Agency for identifying people with (or at risk of) physical frailty in clinical trials. This guidance defines pre‐frailty as an SPPB score of 8‐9 and frailty as an SPPB score of 7 or less 2. Planning to reside in the target area for intervention delivery for at least 18 months