Mobility and strength training with and without protein supplements for pre-frail/frail older people with low protein...

The first objective was to establish the feasibility of conducting a definitive trial to evaluate the effectiveness of mobility and strength training with or without protein supplements for pre-frail/frail older people with low protein intake. The second objective was to finalise outcome measures for a definitive trial.

Multicentre feasibility randomised controlled trial.

Four National Health Service (NHS) community trust physiotherapy departments. We recruited via clinical caseloads, an existing cohort study and community advertising. Participants were adults aged ≥60 years, frail or pre-frail, reporting walking difficulties or slow walking and low protein intake (<1 g protein/kg of body weight (kgBW)/day). The recruitment target was 50 participants.

All participants undertook two times a week mobility and strength training supported by a physiotherapist for 24 weeks. Half of the participants were randomised (1:1) to receive 24 weeks of daily protein supplements to increase protein intake up to 1.6 g/kgBW/day.

Feasibility outcomes assessed recruitment, intervention fidelity, adherence, tolerance and study retention.

We assessed clinical data collection at baseline and 5-8 month follow-up including the short physical performance battery (SPPB), 6 min walk test (6MWT) and participant-reported outcomes. Outcome assessors were blinded.

All participants were analysed in the groups as randomised provided they were not withdrawn from the study before their treatment started and contributed outcome data (modified intention to treat). Our primary feasibility and secondary outcome measures were summarised using descriptive statistics such as mean and SD, median and IQR or counts with percentages. Secondary objectives were exploratory, and mean between group differences at follow-up were estimated for each continuous outcome using linear regression models adjusted for baseline outcome score and frailty status, and presented with associated 95% CIs.

Initially, recruitment focused on existing caseloads, but patients were more unwell and disabled than anticipated and ineligible. No participants were recruited from the cohort. A community recruitment strategy was implemented. We screened 952 older adults and 20 participants were randomised. We ran out of time to reach our target.We achieved good intervention fidelity for both interventions. The median number of exercise sessions completed was 10.5/16 (IQR 7-13). Six participants received supplements which they tolerated well and took regularly. 14 participants (70%) attended follow-up assessments with no difference in retention between arms.The median age of participants was 76 years (IQR 68.5-80.0) and 15/20 (75%) were frail. All clinical outcomes showed a trend towards larger improvements in the exercise and protein arm, but these were not statistically significant. For example, SPPB scores (mean difference 0.93, 95% CI (-2.70 to 4.56)) and 6MWT (mean difference 41.92 m, 95% CI (-39.05 to 122.89)) were both higher in the exercise and protein arm compared to control.

The study was not feasible based on the original protocol. Recruitment was the biggest challenge. We established a more efficient route to recruitment (community advertising) which requires further refinement. Clinical outcomes consistently favoured the exercise and protein group, which should be interpreted cautiously but suggest this question is worthy of further investigation.

ISRCTN30405954.