Our study demonstrates that the three-month exercise and nutritional program resulted in short-term (3-month) frailty status improvement and long-term effect on BMD and serum 25 OH Vitamin D (12-month) among a population-representative sample of frail older adults. The effect of PST on geriatric frailty, mood, and physical performance was less pronounce. We also found some significant improvements in the control (non-EN, non-PST) groups.
Many instruments were created to measure frailty and studies with different instruments were difficult to compare with
]. We chose several recent intervention trials that used modified CHS_PCF for comparison
]. Peterson et al. enrolled 81 older male veterans scored ≥1 on CHS_PCF. Roughly half (N
39) were randomized into a high intensity physical activity telephone counseling group
]. After 6-months, 49% and 69% were still classified as frail respectively (p
0.08). Kenny and colleague reported the effect of 12-month transdermal testosterone patch on 131 older men with low testosterone level, fracture, or low BMD and scored ≥1 on CHS_PCF
]. Improvements of BMD, and lean mass were found, but not physical performance or frailty indicators
]. In another RCT, Li et al. enrolled 310 community-dwelling older adults who scored ≥1 on the CHS_PCF
]. The 6-month individualized multi-factorial care plans after comprehensive geriatric assessments (CGAs) did not improve frailty status. The Frailty Intervention Trial (FIT)
] used similar CGA with individualized care plans approach but enrolled older adults with ≥3 deficiencies; that study is still in progress and so still lacks published outcome data. To our knowledge, ours is the first study to demonstrate that the CHS_PCF categorization is responsive to intervention to with sound clinimetric properties as an outcome measure
When other frailty indicators were considered, several recent reviews found that structured exercise improved physical and psychological determinants, frailty status, and prevented disability in frail older adults
]. However, many researchers called for more unified definition and operationalization of frailty to enhance comparability of different intervention trials
Expert opinions and the results of clinical trials suggest nutritional consultation as a component in frailty interventions
]; but rarely does it stand as an independent intervention on frailty. One recent study showed that diet and exercise was more effective than diet or exercise alone in improving frailty indicators among 93 obese and frail older adults
]. Our study also added new evidence that combination of exercise program and nutritional information had positive impact on frailty.
It is not clear whether exercise and/or nutritional consultation has a positive impact on BMD or 25 (OH) Vitamin D level among frail older adults. In a study of 65 subjects randomized to moderate-intensity on-site exercise training 3 times per week for 9
months,, the subjects’ BMD did not differ from that of 47 subjects randomized to a low-intensity home exercise program
]. Similar to our study, Villareal and colleagues reported positive effect of diet and exercise on improving or preserving BMD from 2 RCTs of 27
] and 93
] obese older adults. This research group
] also found that diet and exercise increased the serum 25(OH) Vitamin D level as in our study.
In our study, subjects in the PST group had better improvement in frailty and PRIME-MD scores than subjects in the non-PST group; but the differences did not reach statistical significance. Even roughly 40% reported exhaustion from the (CES-D)
] questions, their mean PRIME-MD score was quite low (average 2 points) indicating low level of depression. The floor effect might explain parts of the lack of effectiveness of PST.
Some observational studies suggested that frailty is a dynamic process and natural transitions to better status may occur without interventions
]. During the intervention period, our degrees of improvement in frailty status were significantly higher than the natural improvement rates reported from observational studies
]. On the other hand, the improvement rates during the follow up periods were similar to other studies
]. It was encouraging that frailty status could be reversed with proper interventions. However, the effects might not last long when intensive interventions were discontinued.
We felt it unethical to enroll older adults in the control group without basic education material to teach them about self-managements even this might mitigate intervention effect. It is encouraging that subjects received education material only also had improvements in functional status, mood, quality of life, and physical performance.
Strengths and limitations of the current study
The probability sampling design enhances the generalizability of this study to community-dwelling frail older adults without significant cognitive or functional impairments. The quick and valid CCSHA_CFS TV saved us tremendous time and resources in conducting the large-scale community-based frailty screening. Our educational material and interventions would be easily replicable in other settings.
The study also has several important limitations. First, we encountered an unexpectedly low response rate during the telephone-interview stage, with one-third not being reachable after multiple attempts, and another one-third refusing the telephone interviews, which hampers the external validity of the current study.
Second, compliance with the thrice-weekly exercise sessions and PST sessions were fair. Many participants had problems reaching the study site and other personal issues, such as taking care of their grandchildren which prevented them from on-site intervention. The intervention effect could have been enhanced if better adherence had been reached.
Third, the CHS_PCF instrument does not allow assessment of different degrees of frailty as the CCSHA_CFS_TV. However, we were not able to detect more subtle changes frailty degrees with the later instrument since it was only used at the screening stage.
Forth, we did not have use population specific cut-points in the 5 frailty indicators to enroll study participants. At the time of the study design, Taiwanese frailty cut-points with the CHS_PCF were not available. However, since it is an interventional study with a purpose to identify subjects with certain degree of frailty suitable for interventions, it probabably did not matter which cut-points were used as long as study populations could be clearly and systemicly identified and classified.
Finally, the study sample size is relatively small, though it is comparable or greater than some previous interventional studies of frailty
]. In the review conducted by Thou and colleagues
], only 13 out of 47 exercise programs had sample size greater than our study which indicating the difficulty enrolling and conducting RCTs in frail older adults. Since there was a lack of previous data to guide estimation of sample size based on our designated primary outcome, one purpose of this study was to determine feasible sample size for future study.