You can measure almost every health metric on your wrist these days. And many Americans do. One in six consumers in the United States now uses a smartwatch or fitness band. Footsteps, heart beats, and even ECG monitors are now integrated into wearables.
If you are looking to wearables to help you relieve stress or achieve “healthy” sleep patterns, don’t bother.
Measurements are important only if they help achieve an outcome. Continuous monitoring of individuals over long periods of time is new and the benefits and pitfalls are yet to be comprehensively evaluated.
One of the major problems is that it is difficult to get normal ranges for the measurements. Take footsteps, which are the most commonly captured variable in the wearable world. Most programs reward 10,000 steps a day. The evidence for the cardiovascular benefit of exactly 10,000 steps is unclear, but it is a nice round number. After all, it is a pain to remember to set different step measures for different problems: for example, 8165 steps to achieve significant weight loss when used with a diet, 6034 to achieve moderate weight loss when used with a diet, or 1000 steps on the first day postoperatively if you don’t want to be readmitted. A mere 6000 steps a day will get you 0.2 frequent flyer points with an Australian airline.
If you are looking to wearables to help you relieve stress or achieve “healthy” sleep patterns, don’t bother. No number of steps or counting time periods improves sleep or reduces stress. At least every second person in the Western world experiences some kind of disturbance and the amount of sleep the experts say that we need is decreasing. Now it is acceptable as an adult (of some indeterminate age) to have only six hours sleep a night and if you are over the magic 64 years old, you only need five hours.
So, at best a wearable can function as an alarm clock signifying when you have had enough sleep. Besides, only five percent of wearable technologies for monitoring stress and sleep have been formally validated. The majority of manufacturers of wearables provide no empirical data to support the effectiveness of their products. One recent study that compared the tracking of physical activity between devices showed large variations in accuracy; up to 25% differences.
Validation just means they are measuring what they say they are. It doesn’t mean the measurement is helping us get to an outcome. Wearing a smartwatch or fitness band won’t get you to sleep or give you better sleep unless you like to count seconds instead of sheep.
The role of wearables is evolving, and at the moment they are no more than measurement tools for the committed. Wearables focus on measurements that erroneously are equated to health benefits.
While the fidelity of wearables is not yet established, just like most new health technologies, they hold early promise for diagnostics but linking them to health outcomes is a long way off.