Effect of a Multicomponent Home-Based Physical Therapy Intervention on Ambulation After Hip Fracture in Older Adults: The CAP Randomized Clinical Trial
Magaziner J, Mangione KK, Orwig D, et al. Effect of a multicomponent Home-Based Physical therapy intervention on ambulation after hip fracture in older adults. JAMA. 2019;322(10):946. doi:10.1001/jama.2019.12964Link to Original Article: https://jamanetwork.com/journals/jama/fullarticle/2749599
Key Points
1. A multicomponent home-based physical therapy intervention did not result in a statistically significant improvement in the ability to walk 300 m or more in 6 minutes after 16 weeks for older adults recovering from hip fracture.
2. The intervention included aerobic, strength, balance, and functional training, and the active control group received transcutaneous electrical nerve stimulation and active range-of-motion exercises.
3. Both groups received 2 to 3 home visits from a physical therapist weekly for 16 weeks, as well as nutritional counseling and daily vitamin D, calcium, and multivitamins.
4. Among the participants, 22.9% of the training group and 17.8% of the control group became community ambulators (walked 300 m or more in 6 minutes) after 16 weeks, but the difference was not statistically significant.
5. The two groups had similar rates of adverse events during the intervention period, with falls being the most commonly reported adverse event.
6. The findings suggest that the multicomponent home-based physical therapy intervention did not significantly improve community ambulation compared to the active control intervention.
Introduction
Hip fractures are a significant public health issue, with projections indicating a substantial increase in the number of hip fractures in the United States and worldwide. Many individuals experience difficulty walking after a hip fracture, and there is a lack of evidence regarding the effectiveness of exercise interventions to improve walking ability in this population. Community ambulation, which involves endurance, dynamic balance, quadriceps strength, and sufficient walking speed, is an important functional outcome. Previous exercise trials have shown positive outcomes, but they were limited in their ability to determine the true effect of treatment versus intensive contact with professionals, and did not evaluate the impact on community ambulation. The Community Ambulation Project aimed to address these limitations by testing a home-based multicomponent intervention targeting specific walking-related abilities compared to a nonspecific active control intervention. The study sought to determine whether the training intervention was superior in facilitating community ambulation at 16 weeks after randomization.
Methods
Inclusion Criteria
The inclusion criteria for this study focused on a specific group of individuals. Participants needed to have a hip fracture that was the result of minimal trauma and had undergone surgical repair. They also needed to be at least 60 years old, living in the community at the time of the fracture and randomization, and able to walk without human assistance two months before the fracture. Additionally, participants had to walk less than 300 meters during the 6-minute walk test when they were randomized.
Exclusion Criteria
On the other hand, exclusion criteria were used to eliminate certain individuals from the study. These criteria included medical contraindications for exercise, a low potential to benefit from the intervention, and practical barriers to participation. These criteria were established in order to create a homogeneous group and ensure that the results of the study were not influenced by factors that could confound the findings.
Procedures
The study involved randomized participants who were assessed at baseline, 16 weeks, and 40 weeks of follow-up. The randomization process took place between September 16, 2013, and June 20, 2017, with follow-up ending on October 17, 2017. In order to speed up recruitment and save resources, the eligibility criteria were expanded twice, the frequency of intervention visits was reduced from 3 to 2 times per week, and make-up intervention visits were allowed. Additionally, the target sample size was reduced from 300 to 210, the 40-week follow-up was discontinued, and some outcomes were eliminated. Telephone interviews were conducted every 4 weeks to monitor adverse events. Participants were aware of their treatment group and were not blinded to it.
Randomization
In this research study, the random allocation sequence was designed by the study biostatistician using a secure web-based system. The enrollment activities were carried out by trained staff who received instructions from the study's clinical coordinating center. Treatments were assigned to participants based on separate randomization schedules for each clinical site. These schedules consisted of randomly ordered blocks with sizes of 2, 4, 6, or 8 participants. Within each block, an equal number of participants were assigned to each treatment. This randomization process ensured that the treatment assignments were unbiased and not influenced by any factors, allowing for a fair comparison between the different treatments.
Interventions
The interventions section of the research paper describes the treatment provided to the participants in the study. Both treatment groups received in-home intervention visits by physical therapists for 60 minutes on nonconsecutive days over a period of 16 weeks. The first 75 participants received 3 visits per week for the first 8 weeks and 2 visits per week for the remaining 8 weeks, totaling 40 assigned visits. Participants who were randomized after a protocol change received 2 visits per week, resulting in 32 assigned visits.
The focus of the training intervention was on improving lower extremity strength, endurance, balance, and function. Strength exercises targeting relevant muscles were performed on the floor. Overall, the study implemented a structured and consistent treatment approach to address the specific goals of improving lower extremity function and mobility in the participants.
The intervention included exercises such as locomotion-appropriate movements, strength training, and endurance exercises. The control intervention consisted of seated active range-of-motion exercises and sensory-level TENS unit application. Both groups also received daily supplementation of vitamin D, calcium, and a multivitamin. Adherence to visits and treatment fidelity were monitored throughout the study. Physical therapists were randomly assigned to treatment groups and were unaware of the alternate treatment or study outcomes.
Outcomes
The outcomes section of the research paper describes the assessments and measurements used to evaluate the effectiveness of the intervention. The primary outcome was community ambulation at 16 weeks, defined as walking 300m or more in 6 minutes. This represented the ability to walk independently and without difficulty outside of one's residence. If the 6-minute walk test could not be performed, a panel of experts evaluated whether the participant was a non-community ambulator based on specific criteria. Secondary outcomes included endurance, dynamic balance, quadriceps strength, gait speed, and physical performance. Tertiary outcomes included lower extremity function and improvement of 50m or more on the 6-minute walk test. Several other outcomes were not reported in this article, such as cost-effectiveness and quality of life. Assessors were blinded to treatment group, and adverse events were monitored regularly. Race and ethnicity information was collected for reporting purposes.
Results
Primary Outcome
This study aimed to assess the effectiveness of a training program on community ambulation in individuals with mild to moderate mobility limitations. The primary outcome was measured using the 6-minute walk test. A total of 187 participants were included in the analysis, with 91 in the training group and 96 in the active control group. Of the participants who did not perform the 16-week walk test, 5 in the training group and 5 in the active control group were classified as noncommunity ambulators.
At the 16-week follow-up, 22.9% of the training group and 17.8% of the active control group met the criteria for community ambulation. There were no significant differences between the groups in terms of community ambulation in any of the subgroups analyzed. However, there was a significant variation in results between clinical sites. Three cases of unblinding of assessment staff were reported. Overall, the findings suggest that the training program did not significantly improve community ambulation compared to the active control group, with variations in results observed at different clinical sites.
Secondary Analyses
The secondary analyses of the research paper found no significant differences between the groups in secondary or tertiary outcomes at the 16 or 40-week follow-up, except for quadriceps muscle strength at 40 weeks, which was greater for the active control group than the training group. Both groups showed significant improvements in 6-minute walk distance, Short Physical Performance Battery (SPPB), modified Physical Performance Test (mPPT), and gait speed from baseline to the 16 and 40-week assessments. There was no evidence of differences between the groups regarding delayed or sustained effects of the training intervention. Using weighted estimating equations to account for potential biases due to missing outcomes, the estimated difference in the proportion of community ambulators was 5.4%, with a 1-sided 97.5% confidence interval ranging from negative infinity to 17.0%. Other sensitivity analyses produced similar results to the primary findings.
Intervention Visit Adherence and Treatment Fidelity
The researchers found that the mean percentage of expected intervention visits completed per participant was 78.3% in the training group and 87.0% in the active control group. A higher percentage of participants in the active control group completed at least 80% of the expected intervention visits compared to the training group. In terms of the targets achieved, the volume target was reached in more visits than the intensity target for both strength and endurance components of training. However, the number of visits in which volume targets were achieved was lower for training than active control. In a post-hoc analysis, it was revealed that the median heart rate during the endurance portion of training visits was significantly higher than during the strength component of training visits or the active control visits. The findings suggest variations in adherence to the intervention visits and highlight the importance of closely monitoring and assessing treatment fidelity.
Adverse Events
The Adverse Events section of the research paper provides information on the occurrence and nature of adverse events experienced by participants in the training group and the active control group during the intervention period. Seventeen participants in the training group (16.2%) and 15 participants in the active control group (14.3%) reported one or more adverse events. The number of adverse events per participant, as well as the severity and relatedness of the events, were similar between the two groups. The most commonly reported adverse events were falls, with 5.7% in the training group and 3.8% in the control group. Additionally, there were instances of femur/hip fractures, pneumonia, urinary tract infections, dehydration, and dyspnea. Three deaths occurred, with one in the training group during the intervention period, one in the active control group after the intervention but before the end of the 16-week assessment window, and one in the active control group after the assessment window.
Discussion
This study aimed to evaluate the effectiveness of a home-based physical therapy intervention in improving various outcomes among older adults with hip fractures. However, the results showed that the intervention did not lead to a statistically significant improvement in the participants' ability to walk 300m or more in 6 minutes compared to the active control intervention. The active control intervention, which included TENS and active range-of-motion exercises, may have had some additional benefits beyond attention and could have contributed to improved walking ability due to the therapeutic alliance established between physical therapists and participants. Both groups showed clinically meaningful improvements in secondary/tertiary outcomes, indicating that both interventions provided greater benefits than usual care for hip fractures. The study also highlighted the well-established heterogeneity of response to progressive strength training in older adults, suggesting that factors such as exercise dose, adherence, behavioral and environmental factors, and body composition should be considered in future studies.
Limitations
The limitations of this study are as follows: Firstly, the low enrollment of screened patients may limit the generalizability of the findings to all patients with hip fractures. Secondly, missing data may have introduced bias into the results as it is unlikely that the missing data were randomly distributed. Thirdly, participants could not be blinded to treatment due to the nature of the interventions. However, only a small number of participants revealed their treatment group, so it is unlikely that the assessors' knowledge of treatment assignment biased the results. Fourthly, the participants' knowledge of treatment assignment could have influenced their performance on outcome measures, despite efforts to reduce bias. Fifthly, data on long-term effects of the intervention was limited due to a decision made during the study to eliminate a 40-week follow-up. Sixthly, illness and hospitalization may have hindered participants' completion of the intervention protocol. Lastly, the study was not adequately powered to detect smaller meaningful differences, particularly with the reduced sample size. Therefore, differences in favor of the training intervention smaller than the upper limit of the confidence interval (16.3%) cannot be ruled out based on the reported findings.
Opportunities for Future Research
1. Investigate the long-term effects of a multicomponent home-based physical therapy intervention on community ambulation after hip fracture in older adults beyond the 16-week follow-up period.
2. Explore the potential differential effects of the intervention across different clinical sites to determine if there are factors that contribute to variation in outcomes.
3. Examine the impact of exercise dose and adherence on the effectiveness of the intervention and identify strategies to optimize participant engagement and adherence.
4. Assess the role of additional factors such as body composition, behavioral factors, and environmental factors in predicting response to the intervention.
5. Conduct additional analyses to explore potential subgroups that may benefit more from the intervention, such as individuals with specific comorbidities or functional limitations.
6. Investigate the impact of the active control intervention on walking ability and physical function to determine if it has a meaningful effect beyond usual care or attention.
