Abstract
What did i do?
I've measured my sleep quality and quantity and compared with healthy population
How did i do it?
I've used Dreem 2 EEG headband for 160 nights.
What did i learn?
I need to focus on is lowering awake time during night, which should result in less sleep fragmentation and increased sleep quality.
Introduction
Healthy sleep is required for maintain general health. The purpose of this analysis is to compare how far from healthy population my sleep is.
Materials & Methods
Participants
Adult male (n=1) anthropometrics was described in previous article
Experimental design
During 160 nights (from 2020-08-27 to 2021-09-08) sleep quality and quantity was assessed by Dreem 2 EEG Headband which was validated[1] against gold standard PSG. Measures of interest:
- TIB - time in bed
- DEEP - N3 sleep stage
- LIGHT - N1 + N2 sleep stages
- REM - rapid eye movement sleep stage
- TST - total sleep time, sum of DEEP + LIGHT + REM
- AWAKE - time awake
- SOL - sleep onset latency
- WASO - wake after sleep onset
- SE - sleep efficiency, 100 * TST / TIB, %
- Awakenings
- Position changes
As a reference data from a scientific publication will be used [2]
Results
Visual inspection of sleep data:
Purple - DEEP, Cyan - REM, Blue - LIGHT, Orange - SOL, Red - WASO. All measurements in hours.
Sleep disturbance inspection:
Orange - count of awakenings (left Y axis), Red - position changes count (left Y axis), Blue - sleep efficiency (%, right Y axis).
Sleep statistics
| Mean | SD | IQR | Healthy mean | Healthy SD | Hedges G | Effect size | Direction | |
| TST, min | 430 | 51.6 | [408,468] | 427.5 | 38.1 | 0.05 | None | same |
| DEEP, % | 21.7 | 5.4 | [18.2,24.6] | 9.3 | 6.8 | 2.16 | Large | better |
| REM, % | 20.1 | 6 | [15.6,23.9] | 21.6 | 4.7 | -0.25 | Small | worse |
| LIGHT, % | 49.8 | 6.9 | [44.9,54.9] | 62.3 | 6.14 | -1.84 | Large | ? |
| SOL, min | 19.2 | 11.1 | [11.8,22.7] | 18.5 | 19.6 | 0.05 | None | same |
| WASO, min | 26.3 | 22 | [13,32] | 46.6 | 38.9 | -0.77 | Medium | better |
| AWAKE, % | 9.6 | 5.3 | [5.8,11.8] | 6.6 | 5.8 | 0.55 | Medium | worse |
| SE, % | 89.1 | 5.6 | [86,93] | 89.3 | 7.9 | -0.03 | None | same |
N = 39 for healthy adult data and N = 160 for my data. Healthy data is between sjubject, my data is intra-subject. Base for percentages is TIB
Discussion
Comparing intra-subject differences versus between-subject is not a good method, but should be enough for rough comparison:
- Better: more DEEP, Large effect size
- Better: less WASO, Medium effect
- Worse: more AWAKE, Medium effect size
- Everything else differs non significantly from 19-30 years old healthy adults.
Most important thing to focus on is lowering awake time during night. Since i'm 34y and most of my sleep metrics differs not significantly from 19-30y population i conclude my sleep is fairly good.
Important to note a weird lower percentage of deep sleep and higher light sleep from reference study. This might be because of lab environment and i dont take these metrics seriously. More importantly to focus on what was worse - awake time.
Data availability & Information
Welcome for questions, suggestions and critics in comments below.
Data is fully available here.
Statistical analysis
Effect sizes based on Hedge's g, Cohen's 1988 rules