Aspirin and gastrointestinal haemorrhage: a methodologic assessment

Area of Science:

• Gastroenterology
• Pharmacology
• Clinical Epidemiology

Background:

• Aspirin (ASA) is widely believed to cause gastrointestinal bleeding (GIH).
• This belief influences clinical practice, potentially withholding ASA from patients with inflammatory joint disease.
• Existing evidence linking ASA to GIH is often circumstantial and lacks critical evaluation.

Purpose of the Study:

• To critically appraise the literature on the association between aspirin use and gastrointestinal haemorrhage.
• To evaluate the quality of evidence supporting the causal link between ASA and GIH.
• To inform clinical practice regarding ASA use in patients with inflammatory joint disease.

Main Methods:

• Systematic review of thirteen control studies (seven RCTs, six case-control).
• Assessment of study design, outcome measures, and adherence to causation criteria.
• Evaluation of sampling strategies and their influence on the strength of association.

Main Results:

• No outcome measure was found to be a satisfactory "gold standard" for assessing GIH.
• Studies did not provide sufficient evidence for firm conclusions on causation.
• None of the reviewed studies adequately met causation criteria or eliminated potential biases.

Conclusions:

• The evidence that aspirin causes gastrointestinal haemorrhage is not supported by critical evaluation.
• Physician advice to avoid ASA in patients with prior GIH is sound for casual use.
• ASA should not be withheld for severe inflammatory joint disease based on current evidence of GIH risk.