02.11.2024
A comprehensive analysis of your sleep data has been possible with KIWI HEALTH for some time now.
A new feature is the calculation of a sleep index, which you can use to make statements about your sleep quality. This gives you even more insight into your sleeping habits.
In this article, you can find out in detail how the index is calculated by KIWI HEALTH and what sleep quality is all about.
Introduction
Sleep is an indispensable part of our lives and has an essential influence on our health and well-being. But what exactly does “sleep quality” mean? And how can you measure it? In this article, I would like to introduce you to two useful tools for assessing and improving your sleep quality, namely the concept of sleep quality and the sleep index.
Note:
There are many different approaches to calculating a sleep index. Other apps and websites calculate a sleep index using different methods, factors and/or weightings. It does not make sense to compare two sleep index values for the same night that were calculated using different methods.
What is sleep quality?
Sleep quality refers to the recovery and benefits you get from your sleep. It’s not just about how long how long you sleep, but also how well you sleep. Sleep quality can be influenced by various factors, including the sleep environment, your sleep habits and your general health. Good quality sleep means that you wake up feeling refreshed and rested, ready for the new day.
The sleep index: a measure of sleep quality
The sleep index is a measure that combines different aspects of sleep to provide an overall assessment of sleep quality. It takes into account several metrics, each of which is weighted differently to provide a comprehensive assessment. Below I explain the individual components of the sleep index and how they are calculated.
The key figures of the sleep index
1. Sleep duration (weighting 0.4)
Sleep duration is the total amount of time you spend asleep. It is a key indicator of sleep quality, as both too little and too much sleep can have negative effects. The optimal amount of sleep varies depending on age and individual needs, but is usually between seven and nine hours per night. Either the sleep target you set or the general average of 8 hours is used as a reference.
2. Sleep depth (weighting 0.25)
Sleep depth refers to the different stages of sleep you go through during the night, particularly deep sleep and REM sleep. Deep sleep is crucial for physical recovery and regeneration. REM sleep is important for mental recovery, learning and emotional processing. Consequently, a good quality of sleep depends largely on you spending enough time in these restorative sleep phases during sleep. The calculation is based on the ratio of deep sleep duration plus REM sleep duration to the recommended proportion of total sleep duration (45%, of which 20% is deep sleep and 25% REM sleep).
3. Regularity (weighting 0.2)
Sleep regularity refers to the consistency of your sleep times, i.e. how regularly you go to bed and get up. A regular sleep-wake cycle helps to stabilize your internal clock and improve the quality of your sleep. The standard deviation of your bedtime and wake-up times over the last 14 days is used to calculate regularity.
4. Interruptions (weighting 0.1)
Interruptions are periods of wakefulness during the night that disrupt the continuity of your sleep. Frequent or prolonged interruptions can impair recovery and lead to tiredness and discomfort the next day. The maximum value relevant for the calculation is 7 interruptions per night.
5. Duration of falling asleep (weighting 0.05)
Sleep onset time is the time it takes you to actually fall asleep after going to bed. A short time to fall asleep is a sign of good sleep hygiene and a balanced nervous system, while a longer time may indicate stress or sleep problems. A maximum value of 30 minutes to fall asleep is assumed for the calculation.
Calculation of the sleep index
The sleep index is calculated using a combination of the above key figures, whereby each key figure is taken into account according to its weighting. Here is a simple formula for calculating the sleep index:
The maximum score for each key figure is 100, so that the sleep index is also between 0 and 100. A higher sleep index indicates a better quality of sleep.
Example for calculating the sleep index
Lets assume you have the following values:
- Sleep duration: 7.5 hours with a sleep target of 8 hours (94 points)
- Sleep depth: 78 points
- Regularity: 70 points
- Interruptions: 3 interruptions (57 points)
- Sleeping time: 15 minutes (50 points)
The calculation of the sleep index would be as follows:
A sleep index of 79 indicates a good quality of sleep.
Evaluation of the sleep index
The sleep index is evaluated in KIWI HEALTH as follows:
- 80 – 100: very good
- 60 – 79: good
- 40 – 59: acceptable
- 20 – 39: bad
- 0 – 19: very bad
KIWI HEALTH not only calculates the sleep index and shows you the final result of the calculation, but also displays all partial results of the individual factors. This will make it clearer and more transparent for you which areas you should pay particular attention to.
Conclusion
Monitoring and assessing your sleep quality are important steps towards improving your overall wellbeing and health. The Sleep Index provides a comprehensive and scientifically based method to assess the various aspects of your sleep and identify potential problems. By monitoring sleep duration, sleep depth, regularity, interruptions and sleep onset time, you can take specific steps to improve your sleep habits and ultimately enjoy a more restful and healthier sleep.
You can find out more about sleep and sleep analysis in KIWI HEALTH on the page Sleep analysis – simple and comprehensive with KIWI HEALTH.
