Sleep
Sleep Quality (PSQI)
Put the Sleep Quality (PSQI) measure in context when reviewing sleep-related information.
- How it's examined
- self-reported
- Value type
- numeric
- Unit
- points
- Better when
- lower is better
- Plausible min
- 0
- Plausible max
- 21
- Healthy max
- 5
- How often
- weekly
Moved by
Interventions that trials measured against this marker, and which way it moved.No trial has measured Sleep Quality (PSQI) against an intervention in this library yet.
Via effects
Interventions targeting an effect this marker tracks. Trials did not measure the marker itself.Sleep Quality Improvement
Morning Alertness Improvement
Full write-up
What is it
Sleep Quality (PSQI) is the measurement used to describe this aspect of sleep. It provides a defined way to refer to sleep quality when presenting findings.
How to measure it
Measure Sleep Quality (PSQI) weekly and record the result in points. Keep the schedule consistent from week to week so readings can be compared over time.
Interpret changes using the direction of the scale: lower scores indicate better sleep quality. Focus on the trend across weekly measurements rather than treating a single reading as definitive. Record each result using the same points-based scale and compare only measurements collected at the same weekly cadence.
What good looks like
Sleep Quality (PSQI) is interpreted on a scale where lower scores are better. A result toward the lower end indicates a more favorable pattern, while a result at or below the displayed healthy-range boundary is broadly aligned with the target shown for this measure.
Use the score as an orientation rather than a verdict. The most useful signal is the direction across several weekly readings: scores that remain low or move downward suggest a more consistently favorable pattern, whereas repeated increases may indicate that sleep quality is worsening. One reading can be less informative than the broader trend, so compare readings collected with the same approach over time.
What moves it
Sleep Quality (PSQI) is measured in points, with lower scores indicating better sleep quality. The most relevant evidence comes from trials that measured PSQI itself. Magnesium, Melatonin, Lavender Extract, Vitamin B1 (Thiamine), Vitamin B2 (Riboflavin), and Valerian Root decreased PSQI, while Vitamin E increased it. Lemon Balm (Melissa) left PSQI unchanged in the directly measured evidence. Because lower scores are better, upward movement represents a less favorable direction for this marker. In these studies, PSQI was generally rechecked after 4-13 weeks; Magnesium was assessed at 3 months.
A separate, less direct group concerns outcomes that PSQI tracks rather than PSQI itself. These target what this marker tracks, though trials did not measure it directly. Sleep-quality-related effects have been reported for Yoga, Tai Chi, Meditation, Lavender Extract, Anusara Yoga, and Hatha Yoga. Related findings for morning alertness involve Ashwagandha, Cordyceps, Tai Chi, Caffeine, Cycling, and Astaxanthin, while biorhythm-regulation findings involve Melatonin, Ashwagandha, Tai Chi, Gratitude Journal, Cycling, and Hatha Yoga.
These indirect findings can help describe the broader sleep-related context, but they should not be interpreted as direct changes in PSQI. The direct and indirect groups therefore answer different questions: one measures movement in this exact marker, while the other measures a related sleep, alertness, or rhythm outcome.