Smart watches and Fitbits can cause feelings of guilt if goals are not met, and anxiety from users misinterpreting the data, according to research.
And heart disease patients trying to improve their health have been warned not to use them as they do more harm than good.
Sufferers became more in tune with their health while using a smart fitness tracker, however feelings of guilt and anxiety rose in tandem, the researchers revealed.
A trial found that users experienced fear because they incorrectly linked information from their fitness watch to their illness. They may link a fast heart rate with an increased risk of heart attack, for example, or fear a less than usual amount of sleep will exacerbate their illness.
Study author Dr Tariq Osman Andersen, from the University of Copenhagen said: “Our study shows that, overall, self-measurements are more problematic than beneficial when it comes to the patient experience.
“Patients begin to use the information from their Fitbits just as they would use a doctor.
“However, they don’t get help interpreting their watch data. This makes them unnecessarily anxious, or they may learn something that is far from reality.”
The study, published in The Journal of Medical Internet Research – a peer-reviewed open-access medical journal – researched 27 heart patients who used Fitbit fitness watches to measure their sleep, heart rates and physical activity.
Although the patients, aged between 28 and 74, learned more about their illnesses and were motivated to exercise in the six months they wore the watches they also became more anxious.
Dr Andersen, who completed the study with researchers from Vital Beats, a Danish medtech company, added: “Conversely, the Fitbit watch can be calming, if data shows that you are sleeping well and have a low heart rate.
“The problem is that you cannot use data directly related to heart disease because the watch is designed for sports and wellness, as opposed to managing disease.”
The fitness-tracking watch also made many patients feel more guilty when they fell short of their daily fitness goals.
On the one hand, patients were motivated to be active, but the app also revealed when patients did not reach the recommended 10,000 daily steps, making many feel guilty.
Dr Andersen explained that the guilt was misplaced, and said: “The Fitbit watch is not designed for heart patients, so they should not necessarily follow the same recommendations for exercise as those who are in good health.”
The use of wearable health tech, such as the Fitbit watch, is part of a growing trend to measure activity in healthy people and those with chronic illnesses.
The research team said the fitness watches and their accompanying apps offer great promise for heart patients, helping to engage patients in managing their illness outside of the hospital.
But the team suggests they should now be used in partnership with healthcare professionals to limit unwanted side effects.
Dr Andersen added: “We believe it is time to think in terms of ‘collaborative care’, where both patient and clinicians benefit from the new health data and are thereby able to work together to manage and treat chronic diseases.
“This requires that we create a digital platform in which clinicians and patients can jointly interpret data from, for example, fitness watches, without creating unnecessary additional work for clinicians.”