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Open WellbeingWhat the studies actually measured

Long-term health and immunity

N-acetylcysteineand Respiratory exacerbation rate

Only one source here so far, and it measured lower respiratory exacerbation rate.

How sure anyone can be

Moderate certainty, level 3 of 4

Further research may change this.

The numbers reported

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

0.660.75 risk ratio0.84

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, 2015 · 13 studies pooled · 4,155 participants

    Moderate certainty, level 3 of 4

    Influence of N-acetylcysteine on chronic bronchitis or COPD exacerbations: a meta-analysis.

    Eur Respir Rev. 2015;24(137):451-61. doi:10.1183/16000617.00002215. PMID:26324807.

    Number reported
    0.75 risk ratio
    Which way it went
    Lower
    Likely range
    0.66 to 0.84
    Source’s own words
    relative risk of a chronic bronchitis/COPD exacerbation vs placebo or control
    Who was studied
    Adult with chronic bronchitis or COPD
    Compared with
    placebo or control
    Amount taken
    600 to 1,200 mg/d
    For how long
    Not in the abstract
    Disagreement between studies
    Not in the abstract
    Kind of record
    Journal article
    How this rating was reachedstarts at High, one step down: risk of bias
    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. Ends at ModerateOne step down.
    Checked, nothing to step it down for
    indirectness and imprecision
    Inconsistency
    No high disagreement reported between the 13 studies it pooled

    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

  • For how long — Not in the abstract.

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

Still to read for N-acetylcysteine

Seven of the 18 things on our list for N-acetylcysteine have no reading here yet:

  • Alanine aminotransferase (ALT)
  • Aspartate aminotransferase (AST)
  • Cycling Functional Threshold Power
  • Cycling Power
  • Diastolic blood pressure
  • HOMA-IR
  • Systolic blood pressure

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.