The research suggests that physical data from wearable devices, such as FitBits and step counters, can be clinically significant.

Consumer wearable devices to track health status and progress are commonly used and part of a growing trend of mobile health technology. However, how to interpret data from wearable devices is at times unclear.

"Our research showed increased step counts were significantly associated with improvements in health status, suggesting that increases in step count over time as assessed by a wearable device may be clinically meaningful," said Dr. Jessica Golbus, first author of the paper published in JACC: Heart Failure.

Golbus's team at the University of Michigan in Ann Arbor, sought to determine the relationship between daily activity and patient outcomes for people with heart failure. Researchers used data from a randomized controlled trial that provided 425 participants with a Fitbit and asked them to complete questionnaires through a smartphone application.

The questions measured physical symptoms, quality of life, and social limitation, scored on a scale of zero to 100 with higher scores indicating better health. Changes in scores of five points or more are considered "clinically significant" and have previously been shown to be associated with heart failure outcomes.

After two weeks, the mean physical limitation score was 55.7 and the total symptom score was 62.7. Physical limitation scores increased by four points on average through 12 weeks and total symptom scores increased by 2.5 points.