What are the most effective interventions to improve physical performance in pre-frail and frail adults? A systematic review of randomised control trials

Giné-Garriga et al. [24] incorporated group based exercise focusing on balance, and upper and lower body strength, along with function focused activities designed to mimic everyday tasks. The intervention comprised of twice weekly 45 min classes over 12 weeks. Significant improvements were reported in the primary outcome measures of the Barthel Index, rapid gait test, and stand up test, which were maintained at 36 weeks (all p < 0.05) [24]. Significant improvements were also reported for the intervention group in secondary outcomes including balance, gait speed, and lower body strength (p < 0.05).

A total of 3 physical activity intervention studies were based in hospital settings. One focused on falls prevention [51], while 2 examined effects of a physical function intervention on mobility outcomes following a surgical procedure [48, 49]. The falls prevention program intervention compared Tai Chi with conventional physical therapy for frail older adults at risk of falls [51]. Both groups received twice weekly 60 min sessions for 15 weeks via a group setting for Tai Chi, and individually for the conventional treatment. Both groups improved but the Tai Chi group did not reduce fall frequency significantly better than conventional treatment, even though a trend emerged for lower fall rates in the Tai Chi group. Given that both the Tai Chi and conventional treatment groups had over 40% drop out rates across the duration of the intervention (n = 29 and 35 respectively), any effects may be underestimated due to a lack of statistical power.

Two studies reported on the Trondheim hip fracture RCT [48, 49] which examined physical activity and mobility in the immediate post-surgery days on a geriatric ward compared with a conventional post-surgery ward [48]; assessing gait characteristics at 4 and 12 months post intervention ([49]). The post-operative mobilisation plan comprised: mobilisation 24 h following surgery; mobilisation goals based on initial performance, training and practising activities related to daily living; strength training was also included if required, and ward routines designed to prohibit long periods of sitting or lying.

Taraldsen et al. [48] found that those receiving the intervention had significantly greater upright time (p = 0.016), number of upright events (p = 0.005), and better physical performance than conventionally treated counterparts four days following surgery (p = 0.002) [49] found that significantly more patients could perform the 4 min gait speed test at 4 (p = 0.049), and 12 months (p = 0.005) than conventionally treated patients, and overall had better gait characteristics including pace (p = 0.001), rhythm (p = 0.019), postural control (p = 0.027), and less gait asymmetry (p = 0.004) at 12 months. A significantly higher proportion of participants in the intervention group were able to walk independently (p = 0.006), had better outdoor mobility (p = 0.015), and greater independence when using public transportation at 12 months compared to controls (p = 0.040). Length of stay was slightly longer for the intervention group (12.6 vs 11 days); however, the intervention was found to have an 88% probability of being both less costly and more effective than orthopaedic care in the long run.

Of the 5 studies examining physical activity plus nutrition in a primary care setting, Fairhall et al. [20] and Cameron et al. [8] report data taken from the same RCT of a multifactorial intervention designed to target frailty characteristics including nutritional assessment, physiotherapy and medical management to reduce fall rates. Ten physiotherapy sessions, delivered over a 12 month period, focussed on strength and balance, with high energy, high protein supplements offered to those whose BMI was less than 18.5 (n = 60, 50% of sample).

In total, 25 participants (21%) were recommended vitamin D supplements. Adherence to the nutritional intervention ranged between 26 to 50%. Fairhall et al. [20] found no difference in fall rates between the intervention and conventional treatment groups (p > 0.05). Cameron et al. [8] found significant reductions in frailty status at 12 but not 3 month follow up (p = 0.02). Improvement in physical performance including strength and gait speed were reported at 12 months (all p < 0.001). No differences were found on mortality, hospital admissions, permanent admissions to nursing care facilities, or quality of life outcomes (p > 0.05).

Bonnefoy et al. [6] devised an intervention around existing home help services which combined a self-administered exercise program, (participants were prescribed exercises by a physiotherapist, received a booklet explaining how to perform exercises, a poster showing pictures of the exercises, and how to fill in a compliance diary) alongside a 10 g amino-acid supplementation to be taken under the supervision of the home help. It was expected that the visitation of the home help would also prevent sedentariness as they were trained to encourage physical activity. Overall adherence was poor to the exercise and nutritional components, with only 44% (n = 23/53) of participants being fully compliant. The results of the study suggest limited impact of exercise and nutrition on markers of frailty, including body composition indicators, mobility, or activities in daily living.

Ng et al. [35] randomised participants with a mean age of 70 years to physical exercise, nutrition, cognitive training or combination treatment program for 6 months to examine the impact on frailty characteristics, with specific focus on mobility and strength performance outcomes. Frailty was assessed and included participants who were classified as pre-frail or frail, though no stratified analyses were conducted. The exercise group (n = 48) received a program tailored to their specific ability in classes for 90mins twice weekly for 12 weeks which focused on strength and balance. This was followed by a 12 weeks of home exercises. The nutritional group (n = 49) received supplements of iron and folate, vitamins B6 and B12, calcium and vitamin D for 24 weeks. Cognitive training (n = 50) involved 2 h weekly sessions for 12 weeks of cognitive-enhancing activities designed to stimulate short-term memory, and enhance attention, information-processing skills, reasoning and problem solving abilities. The following 12 weeks included fortnightly booster sessions. The combination group (n = 49) experienced all treatments. Frailty scores were significantly reduced at 6 and 12 months in all groups (all p < 0.05), with combination group reporting the greatest reduction (mean change = 5.00), followed by physical therapy (mean change = 4.05), nutrition (mean change = 2.98) and cognitive therapy (mean change = 2.89). However, there was no clear statistical difference between treatment groups on improving physical performance. Lower body strength improved in the combination, physical activity, and cognition groups (p = 0.009); gait speed improved in the physical activity group only (p < 0.001); overall physical activity improved in the nutrition group (p = 0.038).

The final study by Yamada et al. [52] was the only study that delivered the intervention by remote delivery methods. This was a pedometer based walking program and nutritional supplement (protein and vitamin D) delivered over a 6 month period. Participants were randomly assigned to a walking group (n = 71), walking plus nutrition (n = 79), or control group (n = 77). Adherence levels were very high, with 80% adherence reported for the nutritional component, and 100% for the walking initiative. Muscle mass and biochemical outcomes were assessed. Both the walking and walking plus nutrition groups were successful in improving biochemical outcomes associated with improved muscle mass (IGF-1, 25(OH)D) and skeletal muscle mass index compared with the control group (p < 0.05), but only the walking plus nutrition group had significantly greater improvements in Dehydroepiandrosterone-Sulfate (DHEA-S) (p < 0.05). The number of daily steps also increased significantly in both groups, with an increase from 4471 to 6067 steps in the walking plus nutrition group, and an increase from 3795 to 5394 steps in the walking group. Sub-group analysis was conducted separately for non-frail and frail participants; however the sample size for this analysis was small with only 31 frail vs 46 non-frail in the walking plus nutrition group, 15 frail vs 55 non-frail in the nutrition only group, 25 frail vs 50 non-frail in the control group; however, cautious interpretation suggests that both frail and non-frail participants benefited in improved physical performance from the intervention in comparison to the control group.

Tieland et al. [50] recruited pre-frail and frail participants to receive twice daily protein supplements vs a placebo over a 24 week period; however despite high reports of adherence, there was no difference in any biochemical measure, skeletal muscle mass, or in hand or lower body muscle strength compared to the placebo group. Only physical performance, (a composite score of gait, balance and chair rise test) significantly improved in the protein group at 24 weeks (p = 0.02). The authors report that the increase in physical performance was of substantial clinical relevance and translates to a 30% relative risk reduction for disability and a reduced risk for institutionalization and mortality.