Meta-analysisindependent cross-checkabstract checked★ key study I-PPI-101 in-depth review
Acid blockers prevent bleeding ulcers in trials
Effects of gastroprotectant drugs for the prevention and treatment of peptic ulcer disease and its complications: a meta-analysis of randomised trials.
Overview
Scally B et al.. Lancet Gastroenterol Hepatol 2018 · PMID 29475806 · DOI 10.1016/S2468-1253(18)30037-2
Across 849 randomised trials, acid-suppressing drugs, especially PPIs, strongly reduced ulcers and ulcer bleeding.
Does the study support the specific claim? No · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Summarise all trials of stomach-protecting drugs.
- How was the study done?
Meta-analysis of 849 RCTs.
- How many people, animals or samples were studied?
142,485 participants.
- What was actually found?
Ulcers and bleeding fell markedly; deaths not significantly.
- How large was the observed effect?
Bleeding OR 0.40 overall; PPI 0.21.
- What do the results mean in everyday life?
For people at risk, PPIs prevent dangerous bleeding.
- What are the study's limitations?
Many small, short trials.
- What does it say about Elawady's specific claim?
Contradicts a universal ban on acid blockers.
- Do the results apply to Germany and Europe?
Applies everywhere.
- What can explicitly not be concluded from this study?
Does not show everyone benefits; low-risk users gain little.
Scientific in-depth review
1. Full reference
- Authors
- Scally B et al.
- Journal
- Lancet Gastroenterol Hepatol
- Year
- 2018
- Identifier
- PMID 29475806 DOI 10.1016/S2468-1253(18)30037-2
- Verification
- verified – PubMed efetch 2026-10-26 + Crossref 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
UK Medical Research Council and British Heart Foundation
2. Research question
What are the effects of PPIs, prostaglandin analogues and H2RAs on ulcer development, bleeding and mortality across clinical settings?
3. Study design and population
- Study design
- Meta-analysis – Meta-analysis of tabular data from all unconfounded randomised trials of gastroprotectant drugs
- Population
Participants of 849 placebo/control-comparison trials (prevention, healing, acute bleeding)
- Country
International
- Period
Trials 1950-2015
- Sample size
849 trials, 142,485 participants (vs control)
- Inclusion and exclusion criteria
Unconfounded RCTs of a gastroprotectant vs control or vs another gastroprotectant
4. Methods and endpoints
- Exposure / intervention
PPI, prostaglandin analogue or H2RA
- Comparator
Control (placebo/no treatment) or another gastroprotectant
- Endpoints
Endoscopic and symptomatic ulcers, upper GI bleeding, mortality, rebleeding, transfusion, surgery
- Statistical methods
Fixed-effect meta-analysis of ORs; heterogeneity by class
5. Actual results
- Results
Prevention trials: endoscopic ulcers OR 0.27 (0.25-0.29); symptomatic ulcers 0.25 (0.22-0.29); upper GI bleeding 0.40 (0.32-0.50); mortality 0.85 (0.69-1.04). PPIs reduced bleeding most (OR 0.21, 99% CI 0.12-0.36), irrespective of NSAID use. Acute bleeding trials: further bleeding 0.68 (0.60-0.78), transfusion 0.75, further endoscopic intervention 0.56, surgery 0.72; mortality 0.90 (0.72-1.11).
- Absolute risks
Not reported in abstract
- Authors' conclusion
Gastroprotectants, particularly PPIs, reduce peptic ulcer disease and its complications; benefits may be overestimated owing to small-study bias.
6. Strengths
- Largest synthesis of randomised evidence
- Public funding
- Pre-specified outcomes
7. Weaknesses
- Median trial size 78 and duration 1.4 months
- Small-study bias acknowledged
- No mortality reduction shown
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Comprehensive; small-study effects possible.
9. Assessment of the statistical interpretation
CIs log-symmetric (stats/C-PPI-10_compass_gi_scally.py). Very large consistent relative reductions in bleeding; mortality not significantly reduced.
10. Relevance to the specific claim
High-certainty randomised evidence that PPIs prevent ulcers and bleeding and help in acute bleeding: a universal ban removes a proven protection.
11. Independent contrary findings
Mortality not significantly reduced; benefit depends on baseline risk (COMPASS, I-PPI-102).
12. Transferability to Germany and Europe
Universal pharmacology.
13. Overall methodological judgement
Central evidence against C-PPI-10.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | high |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Absolute benefit in low-risk users.
15. Linked fact checks
- All acid-suppressing medicines (PPIs and H2 blockers) are permanently forbidden; heartburn should stop through the diet, not through drugs. – Studies contradicting or limiting the claim
- PPIs are widely prescribed without a real indication (for example by doctors of other specialties to 'protect the stomach') and are now sold freely. – Studies with mixed or unclear results