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Pooled review (meta-analysis)

Pooled review of 23 studies in adults with illnesses: melatonin improved sleep quality scores

Fatemeh and colleagues · Journal of neurology · 2022

Original title: Effect of melatonin supplementation on sleep quality: a systematic review and meta-analysis of randomized controlled trials.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

Points to benefit

Melatonin lowered PSQI scores (WMD: - 1.24; 95% CI - 1.77, - 0.71). Studies differed a lot (I2 = 80.7%). Benefit was seen in lung disease, metabolic disorders and sleep disorders, but not in mental disorders or brain diseases.

The study at a glance

Type of study
Pooled review (meta-analysis)
Who or what was studied
23 studies · adults with various illnesses (lung disease, metabolic disorders, sleep disorders, mental disorders, brain diseases)
What was tested
Melatonin vs placebo, sleep quality scored on the Pittsburgh Sleep Quality Index (PSQI, lower is better)
What it measured
The question itself: sleep, and safety with long-term use
Who has a stake
No disclosure in PubMed
No disclosure in PubMed.
Journal
Journal of neurology, 2022
Source
PubMed record 33417003. This page is based on the abstract only.

How much this study counts

  • ✓Pools the results of 23 studies.
  • •A pooled review is only as strong as the studies it pools.
  • ✓Measured the question itself: sleep, and safety with long-term use.
  • •The PubMed record has no conflict-of-interest statement.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

This paper is not on the ladder. It is a pooled review (meta-analysis), and reviews and opinion pieces discuss studies that are already counted on the steps below.

↑ Stronger evidence

  1. Trials in people: sleep onset and sleep quality

    8

    2 benefit, 2 mixed, 4 no difference

  2. Trials in people: other measures

    2

    1 benefit, 1 no difference

  3. Trials in people: lab tests or safety

    0

    None among the papers we read.

  4. Population studies

    0

    None among the papers we read.

  5. Blood levels and genes

    0

    None among the papers we read.

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Does melatonin help you sleep?”

A small effect, clearer in children.

Confidence: low. Based on 20 on-topic papers.

Read the full answer

Other reviews on this question

See all 20 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The two reads agreed on every checked field. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
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