Option to access more advanced sleep statistics (such as WASO)

[Vivace2018]

Give the opportunity to look at more advanced statistics regarding sleep (quality).

Advanced statistics:

Lights Off - Time to start trying to sleep (Fitbit start tracking sleep with time awake later than lights off)

→ For instance by tapping/holding the fitbit, after which the fitbit can verify by vibrating twice and saying “goodnight”.

Perhaps the period between this and auto-detecting of fitbit sleep time can be named differently? (restlessness?)

Sleep Onset: First time falling asleep

Sleep Latency: Time between Lights Off and Sleep Onset (Sleep Onset Latency SOL)

Sleep latency is perhaps one of the most important parameters in a sleep study. The duration of time between when the lights are turned off (lights out) as the patient attempts to sleep, until the time patient actually falls asleep, as evidenced by EEG and behavioral parameters changes consistent with sleep, is reported as sleep latency.

Sleep Efficiency (with Lights Off)

Sleep efficiency is another important parameter that refers to percentage of total time in bed actually spent in sleep. It is calculated as sum of Stage N1, Stage N2, Stage N3, and REM sleep, divided by the total time in bed and multiplied by 100. Sleep efficiency gives an overall sense of how well the patient slept, but it does not distinguish frequent, brief episodes of wakefulness. A low sleep efficiency percentage could result from long sleep latency and long sleep offset to lights on time with otherwise normal quantity and quality of sleep in between. Many laboratories report total wake time, that is, the amount of wake time during the total recording time in minutes after the sleep onset. The total amount gives a general estimation for overall quality of sleep. Total wake time is the reciprocal of total sleep time. A high total sleep time percent is always associated with low total wake time percent and vice versa.

WASO - Wake After Sleep Onset = Total time awake again after initial sleep onset
An important reported parameter is wake after sleep onset, also known as ‘WASO’. This refers to periods of wakefulness occurring after defined sleep onset. This parameter measures wakefulness, excluding the wakefulness occurring before sleep onset. WASO time is a better reflection of sleep fragmentation.

When applicable: WASF - Wake time After Sleep Offset = Measures inability to get back to sleep after initially falling asleep

Wake time after sleep offset is known as ‘WASF’ and refers to wakefulness that occurs after sleep offset. Long periods of wakefulness following an atypically early morning awakening could be consistent with one of the classic diagnostic signs of depression. This can be found in elderly patients who have no difficulty in falling asleep, but wake up after three to four hours of sleep and are unable to return to sleep. This pattern may be seen in patients who suffer with depression or anxiety and possibly an effect of medications.

REM latency =  Time from the sleep onset to the first epoch of REM sleep

(Normal = –REM latency 60-120 min)

Another crucial reported parameter is rapid eye movement latency also known as REM latency. Rapid eye movement latency is the time from the sleep onset to the first epoch of REM sleep; therefore, it depends on the patient's sleep latency. The REM sleep cycles every 90 to 120 min intervals throughout the night. The changes in REM sleep latency are considered potential biological markers for a number of sleep-related disorders. REM sleep is very sensitive to the effects of medication, sleep deprivation, and circadian rhythm disorders. The knowledge of patients’ current medications and the quality of sleep the night before the sleep study therefore, is extremely important to review. A short REM latency time may result from withdrawal from tricyclic anti-depressants (TCAs) or Monoamine Oxidase Inhibitor (MAOI) medications. Withdrawal from amphetamines, barbiturates, and alcohol can also cause a shortened REM latency period. Patients with a history of narcolepsy, sleep apnea, and depression may also have short REM latency. Similarly, long REM latency may result from use of REM-suppressing medications, including TCAs, MAOIs, amphetamine, barbiturates, and alcohol. Sleep apnea and periodic limb movement of sleep can also lead to long REM sleep latency.

Show a bit more clearly the Time In Bed (TIB)

If possible to measure: Distinguish Light Sleep into N1 and N2 stage

Sleep staging is described in a separate section of the report. Stage N1 sleep is associated with the transition from wakefulness to sleep and is considered a direct measure of daytime alertness and the subjective refreshing quality of sleep. The quantity and the percentage Stage N1 sleep is an estimate of the degree of sleep fragmentation. A high percentage of the Stage N1 sleep is generally a result of frequent arousals caused by sleep disorders, like sleep apnea, periodic movement of sleep, or snoring. Other causes of sleep disruption, including environmental disturbances, may also lead to increased amount of Stage N1 sleep.

Stage N2 sleep predominates the sleep stages with 50% of the total sleep time. It follows the Stage N1 sleep and continues to recur throughout the night. A low percentage of Stage N2 sleep may be a result of sleep fragmentation, increased REM, Stage N3 or a result of obstructive sleep apnea-related arousals. An increased amount of Stage N2 sleep may also be noted in age-related changes in sleeping pattern and may be a result of medication effect.

Arousal Index (based on awakenings)

Arousals–interruptions of sleep lasting 3 to 15 seconds–can occur spontaneously or as a result of sleep-disordered breathing or other sleep disorders. Each arousal sends you back to a lighter stage of sleep. If the arousal last more than 15 seconds, it becomes an awakening. You are usually not aware of arousals, but may be aware of awakenings. The number of arousals and awakenings is registered in the study, and reported as a total number and as a frequency per hour of sleep, which is referred to as an index. The higher the arousal index, the more tired you are likely to feel, though people vary in their tolerance of sleep disruptions. As few as five arousals per hour can make some people feel chronically sleepy. In the worst cases of SDB, the index can be 100 or more.

Measurement of deep sleep not at end of night

Finally, I didn’t come across an official measure for it yet. However it seems that having your deep sleep balanced in the first half of your night (and no more deep sleep showing up at the end of the night) is an indication that you’ve satiated your deep sleep and slept well.

[YojanaFitbit]

Thanks a million for sharing this suggestion @Vivace2018! You have excellent points there, I hope it gets a lot of votes. Let's see what other users think.

[luaprelkniw]

No.  The devices aren't accurate enough, and probably can't be made so with current technology.  Besides, Fitbit might impose an app user interface like the recent models that use inscrutable curves, instead of the former simple, readable, and credible data display from older devices.

[Run_LNG]

I doubt it is accurate enough for most of those but I think that the awake time before sensing sleep would be pretty easy to add in and very useful. It is something one would probably have to remember to do as they get into bed, kind of like setting the start of an activity.

[Vivace2018]

It doesn't take any new type of measurements or accuracy.

The only exception is the light sleep division, and I can imagine WASF might be problematic.

Fitbit already shows the onset of phases, the latency is merely the difference between them.

You can already calculate them by hand, which is something I look at myself.

(1) Lights Off --> I manually press sleep as android already

(2) Sleep Efficiency --> Is already being shown as time awake (%), but it would be more accurate to calculate it (also) with Lights Off

(3) WASO (Wake After Sleep Onset) --> Is merely the time awake MINUS the time awake at the very beginning of the night of getting to sleep

(4) REM latency =  The time between sleep onset and the first time you go into REM sleep

(5) Arousal Index = Already being shown as number of awakenings when you go into the excel file, but it would be nice to see a measure of it in advanced view

As far as the fear of loosing the current way of displaying the sleep data; this is why I suggested giving a separate option to look at these measurements besides the simple view.

It wouldn't harm the current situation by keeping that as the standard view, but giving the option to go to advanced view.

I myself would love to have these calculated automatically for me if I go to an advanced set, rather then having to do it all in the excel file myself by hand.

By seperating the simple vs. advanced view you as a user get to decide whether you want to look at the more advanced (perhaps more uncertain) statistics.

As far as the inaccuracy of the Fitbit in measuring sleep, you might be surprised.

It didn't perform that badly when compared to the Gold standard Polysomnography (PSG).

Especially REM sleep is quite accurate.

Other measures gives less certainty (broader confidence interval), but they for sure give some valid core information, albeit a bit more fuzzy.

(It over- or underestimates, but it still gives a valid range in which lies the true measurement.)

And it's getting more accurate with the inclusion of the heart rate data and smarter database use.

[GJBerends]

I need this feature. I will buy the device that can actually do this in a heartbeat.

[YojanaFitbit]

Hi @Vivace2018 and commenters, thanks for sharing this suggestion. We're always striving to enhance Fitbit products and services, and we appreciate all of the input we receive from our customers. We do not currently have plans to release this feature. You can learn more about how Fitbit decides what suggestions get released in our FAQs. For now, we will leave this suggestion open for votes (and closed to comments) so that we can continue to track community demand over time. Thanks for taking the time to share your feedback with us and we will let you know if anything changes.

[rivkaz]

I often wake up dreaming, sometimes twice during the night, and my chart almost always shows me waking up from light sleep, not REM sleep! I suspect that perhaps the HR of people over 70 during sleep might be different from that of younger people, and therefore different parameters must be used for seniors.

[YojanaFitbit]

Hi @rivkaz, thanks for explaining why you would like to have the option to see more sleep details for seniors. This feature suggestion already exists, so I’ve moved your post here. While we don’t currently have plans to release this feature, we always appreciate the passion and creativity that comes out of this Community. Since we know this idea is important to many of you, we have left voting open to continue tracking interest and will post another update if anything changes. To learn more about how Fitbit decides which suggestions get developed, visit our FAQs.