Text-based Intervention Helped Increase Physical Activity

A three-month unsupervised health intervention based on a commercial activity tracker and motivational texts significantly increased daily step counts and improved quality of life in adults with pulmonary arterial hypertension (PAH), according to data from a single-center trial in the U.S.

Since physical activity has been shown to improve clinical outcomes in people with pulmonary hypertension, the findings highlight the potential benefits of this inexpensive and safe intervention in these patients.

Larger, multi-center studies are needed to confirm these findings, the researchers noted.

The study, “A Mobile Health Intervention to Increase Physical Activity in Pulmonary Arterial Hypertension,” was published in the journal CHEST.

Previous clinical and non-clinical studies have shown that exercise training improves exercise capacity, muscular function, quality of life, and possibly heart function in people with pulmonary hypertension.

However, most of these studies used intensive inpatient and/or outpatient protocols, which are not scalable and involve significant participant burden. In addition, supervised exercise training is not “universally reimbursed by insurers and facilities are not widely available, particularly in rural areas,” the researchers wrote.

As such, there is a high unmet need for “alternative approaches to promote physical activity that are safe, scalable, affordable, and accessible to the PAH population,” the team added.

Researchers at the Vanderbilt University Medical Center in Nashville, Tennessee, and Johns Hopkins University in Baltimore, Maryland, conducted a clinical trial (NCT03069716) in adults with PAH to assess whether an unsupervised, text message-based mobile health intervention could increase physical activity, reflected by daily step counts.

A total of 48 patients who were able to walk alone and on stable treatment for at least three months were enrolled at the Vanderbilt Center for Pulmonary Vascular Disease.

After a two-week run-in period, in which participants’ daily step counts were collected to determine their individual step count target, 42 participants were assigned randomly to either undergo the intervention (20 patients) or receive usual care alone (a control group of 22 patients) for 12 weeks.

Participants in both groups, with a median age of 47 years and 86% being women, were asked to wear the Fitbit Charge HR, a commercially available activity tracker, on their wrists.

They all received daily reminders and study team contacts to sync their devices if they have failed to do so in more than 24 and 48 hours, respectively.

The intervention group received three automated texts per day containing real-time progress toward their daily step count target and personalized encouraging messages. Individual step targets increased by 20% every four weeks.

A three-week washout period followed, in which all participants continued to wear the device, but text messages were no longer sent to the intervention group.

The study’s main goal was to assess changes in daily step counts at 12 weeks, while secondary goals included changes in functional capacity, as assessed with the six-minute walk test, quality of life, and heart function.

Other efficacy outcomes, such as breathing ability, daily active time, resting heart rate, and body composition, also were assessed.

Positive results

Results showed the target patient population was enthusiastic to enroll and highly adherent, with a low dropout rate.

Compared with the control group, patients undergoing the text-based intervention wore the device significantly longer during week 12 (112.2 vs. 103.8 hours) and achieved daily step count targets more often — 41% vs. 24% of study days.

In addition, at week 12, the intervention group had taken a mean of 1,409 more steps (more than half a mile) relative to study start, while the control group took a mean of 149 fewer steps. A significant superiority in daily step counts was observed in the intervention group from day 9 through the end of the intervention period.

This reflected a significantly greater number of steps, and thereby greater physical activity, among participants receiving the text messages, compared with those in the control group at the end of the 12-week period.

During the three-week washout period, the mean number of daily steps remained higher in the intervention group than in the control group (5,509 vs. 4,011 steps), but this difference did not reach statistical significance.

Among other goals, the intervention was associated with significant improvements in patients’ quality of life and emotional well-being, and a significant reduction in visceral fat volume. A nearly significant improvement in heart function also was observed in the intervention group, compared with the control group.

Regarding the lack of significant functional improvements after the text-based intervention, the researchers hypothesized that the intensity of the step count targets in the study may have been insufficient to increase participants’ aerobic capacity. But it was adequate to result in quality-of-life and well-being benefits often linked to regular physical activity.

They also noted that extending this type of intervention to six months or more may lead to more obvious improvements in functional capacity, body weight, and insulin sensitivity.

No serious adverse events were associated with the intervention.

“We demonstrated the feasibility of an automated text-based, unsupervised mobile health intervention to increase step counts in patients with PAH,” which was inexpensive, safe, and well tolerated, the researchers wrote.

These findings suggest “potential for mobile health interventions to improve physical activity and quality of life in patients with PAH,” they added.

Among the study’s limitations, the team noted the single-center nature of the study, meaning that the results may not be generalized to the larger PAH population, and the high number of highly functional patients included in the study, which may have influenced the study’s findings.

More studies involving a greater number of patients from distinct locations and with different functional abilities are needed to confirm these findings.

Also, the use of commercially available tracking devices rather than research-grade devices, and the fact that the devices were placed on a person’s wrist  instead of the hip, may have reduced daily step count accuracy, the team added.