It’s not overstating to assert that step counters and fitness trackers have gained traction worldwide. In 2018, manufacturers reported slightly more than 70 million fitness and activity trackers shipped worldwide, according to Statistica. Fitness wearable category leader Fitbit sold 16 million devices in 2019. Newer fitness trackers often show heart rate, sleep stages, resting pulse, and other biometric measures.

In 2018, we covered a study by Cedars-Sinai and UCLA to see if cardiac patients would use fitness trackers more reliably than other telehealth monitoring devices. The study team issued FitBit Charge 2 fitness bands to 200 patients to track their use of the device to measure heart rate and identify sleep periods. That study concluded that wearables like the FitBit could be effective tools at monitoring the progress of heart disease patients after discharge from the hospital.

A recent paper by researchers from the University of Copenhagen published in the Journal of Medical Internet Research questioned how patients with heart disease react to data from consumer tracking devices. In this qualitative study, 27 cardiac patients were issued Fitbit Alta HR trackers. Researchers then conducted semi-structured interviews followed by thematic analysis in workshops. Eighteen of the 27 patients interviewed related the trackers’ heart rate, sleep, and step data to their disease. Thematic evaluation of the interviews yielded a wide range of reactions ranging from gaining insight, raising doubts, being reassured, becoming anxious, and evaluating their own data in a more positive or negative light.

The study authors concluded that because patients had a wide variety of experiences with the tracker data that trackers have the potential to increase patient concern and anxiety in spite of the fact that they also produce useful information. Tariq Osman Andersen, an assistant professor at the University of Copenhagen’s Department of Computer Science, concluded in an article published by the University that self-measurements were more problematic than beneficial for patients unless doctors helped interpret the data.

If the study had merely pointed out that different people in an anecdotal, qualitative research project had various reactions to fitness data, we would not argue. Many people have ambiguous feelings about fitness and health data. The authors of the study take a step further to present consumer fitness trackers with a caution that seems to us unfounded. Clearly, from interview quotations cited in the study, an unspecified percentage of the patients found the tracker data helpful. Others, again unquantified because this is a qualitative study, found the information confusing or disappointing. Some patients consumed tracker data with more gravity than the researchers believe was warranted.

It would be helpful to read additional studies on the same topic. We find it difficult to find practical insights from loose analysis such as the following statement from the Copenhagen study’s conclusion, “Patients’ experiences could reside more on one end of the spectrum, could reside across all 3 dimensions, or could combine contrasting positions and even move across the spectrum over time.” That seems to cover just about all the possible outcomes.