← Metformin × adverse events & safety

SynthesisOncotarget2017

Metformin therapy and risk of colorectal adenomas and colorectal cancer in type 2 diabetes mellitus patients: A systematic review and meta-analysis.

Feifei Liu et al.PubMed ↗Full text ↗Publisher ↗

  • Metformin therapylooks good hereLower colorectal cancer risk.Correlation only, not a test of it.
  • Metformin userslooks good hereLower colorectal cancer risk.Correlation only, not a test of it.

What moved togetherboth groups pooled, not the treatment’s effect

Correlation, not cause

Metformin therapy went with lower colorectal cancer risk

−27%−38% to −14%

metformin therapy

Bigger than 6 in 10 for adverse events & safety

As reported

OR 0.73, 95% CI 0.62–0.86

Correlation, not cause

Metformin users went with lower colorectal cancer risk

−22%−30% to −13%

metformin users vs non-metformin users and other treatment users

Bigger than 5 in 10 for adverse events & safety

As reported

OR 0.78, 95% CI 0.70–0.87

Who was studied, and how

people with type 2 diabetes, in this paper

Already taking metformin therapy, or nottheir own situation, not assigned

on metformin therapy
not on metformin therapy

Metformin therapy went with lower colorectal cancer risk−27%

correlation, not a test

Already taking metformin users, or nottheir own situation, not assigned

on metformin users
not on metformin users and other treatment users

Metformin users went with lower colorectal cancer risk−22%

correlation, not a test

the abstract, start to end

… risk was also observed (unadjusted OR=0.73, 95% CI: 0.62-0.86, p=0.0002).

… and other treatment users (adjusted OR=0.78, 95% CI: 0.70-0.87, p<0.00001).

← favours treatmentfavours comparator →
could be chance
Colorectal cancer riskmetformin therapy
OR 0.730.62–0.86
Colorectal cancer riskmetformin users vs non-metformin users and other treatment users
OR 0.780.70–0.87
MetforminAdverse events & safety
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