Smartphone apps that promise to track sleep may leave insomniacs so anxious they can't sleep at all, health experts warn.
A flurry of new apps and devices have hit the market in the past year that claim to accurately monitor and even improve the quality and quantity of your sleep.
But specialists at the Sleep Health Foundation say these products must be used with caution, particularly by people with sleep disorders.
"Pouring over data on your sleep can be fun and may even shed some light on how you sleep, but there can be a downside," says Dr Siobhan Banks, Senior Research, Sleep Health Foundation.
"It's important to realise their accuracy is often questionable. If you're one of the 1.2 million Australians with a sleep disorder like insomnia or sleep apnea these monitors might give you false reassurance or worse still, more anxiety about not getting 'enough' sleep that can lead to yet more troubles with sleeping."
Smartphone apps like Sleep Cycle and Sleep Time+ have enjoyed huge popularity in recent times, claiming spots among the top 10 paid health and fitness apps in the Apple App Store.
These apps use the Android or iPhone's in-built accelerometer to measure how much movement you make during your sleep. This allows the app to estimate sleep time and quality but, as Dr Banks warns, the level of sensitivity of the accelerometer in each phone can vary greatly, affecting their accuracy.
Sleep trackers also come in the form of wrist watch technologies like Fitbit, which are used globally to track and analyse sleep patterns, stages and efficiency. These worn devices often carry extra sensors to measure skin, room temperature and body composition.
But these too can give greatly varied results, according to recent studies showing the Fitbit managed to over-estimate and under estimate a person's sleep by more than an hour.
Dr Banks said for people just wanting to get a general idea of their sleep patterns, this won't be a problem.
"In fact, it might help some people understand and review their sleep and wake patterns, and this may ultimately improve their sleep," she says.
"They might notice they have a pattern of repeatedly going to bed late and sleeping less than they should and they might be inspired to go to bed earlier."
But the influx of data may not be that helpful for an insomniac who finds themselves compulsively checking their statistics and worrying about their lack of sleep.
For these people, Dr Banks recommends avoiding sleep tracker technology altogether, or only checking the data infrequently.
The inaccuracy of the information could also cause concerns for people with sleep apnea, a common and potentially serious sleep disorder in which breathing repeatedly stops and starts throughout the night.
"A person's very fragmented eight-hour sleep could get a five-star score for sleep quality," she says.
The Sleep Health Foundation has produced a new fact sheet on sleep tracker technology that is freely available on the organisation's website, http://www.sleephealthfoundation.org.au/index.php?option=com_content&view=article&id=724:sleeptracker&catid=98:fact-sheets, for those seeking the latest in sleep health advice.
Foundation chair Professor David Hillman urges those interested in the new technology to proceed with caution.
"In general the sleep tracker apps and devices will give you a good overview of how long you sleep but they can only tell you so much," Prof Hillman says.
"You have to use the data to figure out what's working for you and what isn't. If you think there is a problem, regardless of what the sleep tracker data is telling you, talk to your GP."
Track Sleep With Caution
- These are consumer products and most have not undergone scientific evaluation. Don't put too much trust in these devices to accurately monitor sleep.
- A single night is not always a very accurate reflection of your general sleep; one night's "data" shouldn't be cause for alarm. If you tend to worry about your sleep then it might be best for you to avoid sleep trackers, or only look at the data occasionally.
- Have fun! Collecting data about yourself can be very interesting. But just remember sleep trackers tend point to general trends in your sleep. The specifics need more sophisticated assessment.
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