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Open WellbeingWhat the studies actually measured

Heart and blood pressure

Omega-3 fatty acids (EPA/DHA)and Atrial fibrillation incidence

Only one source here so far, and it measured higher atrial fibrillation incidence.

How sure anyone can be

Low certainty, level 2 of 4

Further research is likely to change this.

The numbers reported

One source’s range, drawn against its own line of no difference and scaled to its own numbers.

1.071.25 hazard ratio1.46

This range stays on one side of the no-difference line.

Bar the confidence interval — the range the true effect is likely to sit inNotch the number the source reportedLine where there would be no difference at all

One source, newest first

What we read is the published abstract, not the full paper, so a blank below may still be printed in the paper itself. A fixed rule worked this out from the source’s own fields. Nobody checked this rating by hand.

  • Systematic review, 2021 · 7 studies pooled · 2,905 participants

    Low certainty, level 2 of 4

    Effect of Long-Term Marine ɷ-3 Fatty Acids Supplementation on the Risk of Atrial Fibrillation in Randomized Controlled Trials of Cardiovascular Outcomes: A Systematic Review and Meta-Analysis.

    Circulation. 2021;144(25):1981-1990. doi:10.1161/CIRCULATIONAHA.121.055654. PMID:34612056.

    Number reported
    1.25 hazard ratio
    Which way it went
    Higher
    Likely range
    1.07 to 1.46
    Source’s own words
    hazard ratio for incident atrial fibrillation, marine omega-3 vs control
    Who was studied
    Adult with elevated cardiovascular risk
    Compared with
    placebo/control in cardiovascular outcome trials
    Amount taken
    Recorded detail — g/d marine omega-3 (trials stratified at 1 g/d)
    For how long
    365 days (upper bound: Not in the abstract)
    Disagreement between studies
    Not in the abstract
    Kind of record
    Journal article
    How this rating was reachedstarts at High, 2 steps down: risk of bias and imprecision
    1. Starts at High
    2. Risk of bias brought it down to Moderatethe abstract reports no risk-of-bias or quality appraisal, so study limitations cannot be ruled outNot in the abstract
    3. Imprecision brought it down to Lowthe interval excludes no effect but spans a 7-fold range of effect size, from trivial to largeReported in the abstract
    4. Ends at Low2 steps down.
    Checked, nothing to step it down for
    indirectness
    Inconsistency
    No high disagreement reported between the 7 studies it pooled

    Imprecision stops at the first check that applies; others may apply too.

    AI review could not confirm it — an AI agent re-read this finding against the saved source and at least one check failed. The batch record names the check and quotes the sentence that caused the doubt. No person read it.

    Read the abstract on PubMed

What is still missing from these readings

Every reading here records a range, a count of people, an amount and a length of time.

Something nobody wrote down is never a zero and never a guess.

Still to read for Omega-3 fatty acids (EPA/DHA)

Seven of the 19 things on our list for Omega-3 fatty acids (EPA/DHA) have no reading here yet:

  • Alanine aminotransferase (ALT)
  • Cognitive performance
  • Gestational length
  • HDL cholesterol
  • Heart rate variability (RMSSD)
  • High-sensitivity CRP
  • Resting heart rate

Still to read means nobody here has got to it, not that it was tried and did nothing or that no research exists. A pairing on no list is not a gap: we never set out to read it.

Read next

This is a library, not advice. No recommendation, no dose, no diagnosis, no ranking. We never ask about your symptoms, and nothing here is tailored to you.