Results Summary
What was the research about?
Peripheral artery disease, or PAD, affects 8 million people in the United States. PAD narrows arteries in the legs. When this happens, the muscles don’t get enough oxygen-rich blood. People with PAD may have leg cramping, pain, or tiredness while walking or climbing stairs. Walking regularly for exercise may help reduce symptoms of PAD.
In this study, the research team created a program to help patients with PAD walk for exercise. Patients in the program walked at home and wore a Fitbit® activity tracker to record the number of steps walked per day. Trained coaches helped patients set walking exercise goals and record their activity on the study website. Patients also practiced walking with the coach. Coaches called patients regularly to check on their progress with the walking program.
The research team compared the walking ability of patients in the at-home walking exercise program with those who weren't in the program. Walking ability includes how far and fast people can walk and whether they have pain when walking. The team also looked at patients’ ability to carry out physical and social activities and how much pain interfered with their daily lives.
What were the results?
Patients in the program and those who weren't in the program didn’t differ in walking ability, physical function, or social activities. At the end of the study, patients in the at-home walking exercise program reported more pain than patients who weren’t in the program.
Who was in the study?
The study included 200 patients with PAD. Of these, 50 percent were African American, 47 percent were white, 2 percent reported other race, and 1 percent declined to provide information on race. The average patient age was 70, and 53 percent were women. Patients received care at clinics in three states.
What did the research team do?
The research team assigned patients by chance to one of two groups: the at-home walking exercise program plus usual care provided by their doctors, or usual care alone.
At the start of the study and nine months later, the research team tested how far patients could walk in six minutes. The team also asked all patients in the study to wear a device on their right hips for seven days to record patients’ rest and physical activity. Patients took surveys that asked about pain; physical and social function; and walking distance, speed, and stair climbing.
Doctors and patients with PAD helped the research team design the study and recruit people to be in the study.
What were the limits of the study?
Only 79 percent of patients in the at-home walking exercise program completed all follow-up calls. Results may have differed if more patients in the program had completed the calls.
Future research could look at other ways of helping patients with PAD find ways to walk for exercise.
How can people use the results?
Doctors can use the results when considering ways to help patients with PAD walk for exercise.
Professional Abstract
Objective
To compare the effectiveness of a home-based walking intervention with usual care on improving six-minute walking distance, physical function, pain, physical activity, and social functioning among patients with peripheral artery disease (PAD)
Study Design
| Design Elements | Description |
|---|---|
| Design | Randomized controlled trial |
| Population | 200 patients with PAD |
| Interventions/ Comparators |
|
| Outcomes | Primary: change in 6-minute walk distance Secondary: patient-reported measures of pain interference, mobility, walking impairment (distance, speed, and stair climbing), physical function status, physical activity data, and ability to engage in social roles and activities |
| Timeframe | 9-month follow-up for primary outcome |
This randomized controlled trial evaluated the effectiveness of a home-based walking intervention using telephone coaching and a wearable activity monitor on improving walking, physical function outcomes, and social functioning, compared with usual care.
Researchers randomly assigned patients to one of two groups. Patients in the intervention group received a Fitbit® activity tracker to monitor number of steps walked per day and attended four weekly sessions with a coach to set walking exercise goals and practice walking. Patients learned how to record walking activity on the study website and did so once each week. After the first month, coaches and patients met primarily via telephone, weekly at first and then monthly for the last four months of the intervention. Patients in the second group did not receive on-site sessions or coaching. All patients received usual care for PAD from their physicians.
The study included 200 patients with PAD receiving outpatient care at three clinics in three states. Of these, 50% were African American, 47% were white, 2% selected race, and 1% declined to provide race information. The average patient age was 70, and 53% were female.
At baseline and nine months later, researchers measured walking distance using the six-minute walk test. Researchers also measured all patients’ rest and physical activity cycles for seven days using an ActiGraph worn on the right hip to monitor movement. Patients completed questionnaires for other secondary outcomes including walking impairment, physical function status, mobility, ability to engage in social roles and activities, and the degree to which pain interfered with activities.
Every three months, researchers called patients in each group to collect data regarding their walking exercise and physical activity. For safety purposes, they also called all patients monthly to ask about new or worsening symptoms of chest pain, dyspnea, or weakness on exertion and any hospitalizations during the past month.
Patients with PAD and healthcare providers worked with researchers to plan and conduct the study.
Results
Six-minute walk distance. After nine months, patients in the intervention and usual care groups did not differ in mean six-minute walk distance.
Pain, physical function, physical activity, and social health. After nine months, patients in the intervention group reported significantly higher pain interference levels than patients in the usual care group. The two groups did not differ significantly with respect to walking impairment, changes in mobility or physical activity, or satisfaction with social roles and activities.
Limitations
Only 79% of patients in the intervention group completed all scheduled coaching calls. Results may differ with higher adherence.
Conclusions and Relevance
Compared with usual care alone, a home-based walking exercise intervention with telephone coaching did not improve walking or other outcomes for patients with PAD.
Future Research Needs
Future research could examine other ways of encouraging patients with PAD to walk for exercise.
Final Research Report
View this project's final research report.
Journal Citations
Results of This Project
Related Journal Citations
Peer-Review Summary
Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.
The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments.
Peer reviewers commented, and the researchers made changes or provided responses. The comments and responses included the following:
- Reviewers asked for a clearer picture of the depth and scope of feedback obtained from focus groups. Researchers said they did not record quantitative data from the focus groups nor did they perform a formal qualitative analysis of the discussions. The researchers revised the report to include more detail on the feedback obtained, and they noted the lack of quantitative analysis of focus group data as a study limitation.
- Reviewers expressed curiosity about the fact that five people in the intervention group had leg revascularization treatment, while none of those in the control group did. The researchers responded that they did not anticipate this difference and agreed that this might have had the potential to bias the study in favor of the intervention group. Since the findings showed no benefit from the intervention, the researchers concluded that the different rates of lower extremity revascularization did not affect the conclusions.
- Reviewers asked why the researchers added an accelerometer as a study outcome for Aim 2. The researchers explained that this decision was the result of two on-site stakeholder meetings, where participants decided to add a second objective outcome measure, in addition to the six-minute walk test.
- Reviewers suggested that changing from a single-center study to a multicenter study should be noted as a limitation. The researchers addressed the issue in the revised report but disagreed that this change was a limitation, since they said multicenter trials are generally considered more generalizable and more valid than single-center trials. The researchers added that they discussed the switch with stakeholders, who agreed that it was important to reach the target sample size and complete the trial in a reasonable amount of time. Also, training was uniform across research sites.