Meta-analysisindependent cross-checkabstract checked★ key study I-WHT-105 in-depth review
About 1 in 31 people with iron-deficiency anaemia has coeliac disease
Prevalence of Celiac Disease in Patients With Iron Deficiency Anemia-A Systematic Review With Meta-analysis.
Overview
Mahadev S et al.. Gastroenterology 2018 · PMID 29689265 · DOI 10.1053/j.gastro.2018.04.016
Across 18 studies, 3.2% of patients with iron-deficiency anaemia had biopsy-confirmed coeliac disease (5.5% in better studies).
Does the study support the specific claim? No · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
How often IDA is due to coeliac disease.
- How was the study done?
Meta-analysis.
- How many people, animals or samples were studied?
2998 patients.
- What was actually found?
3.2% pooled.
- How large was the observed effect?
1 in 31.
- What do the results mean in everyday life?
Anaemia needs medical testing.
- What are the study's limitations?
Heterogeneity.
- What does it say about Elawady's specific claim?
Contradicts the flour-coating explanation.
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
Does not explain the other 95%.
Scientific in-depth review
1. Full reference
- Authors
- Mahadev S et al.
- Journal
- Gastroenterology
- Year
- 2018
- Identifier
- PMID 29689265 DOI 10.1053/j.gastro.2018.04.016 · PMC7057414
- Verification
- verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
NIH (NIDDK) grant
2. Research question
What is the prevalence of biopsy-confirmed coeliac disease in iron deficiency anaemia?
3. Study design and population
- Study design
- Meta-analysis – Systematic review and meta-analysis of prevalence studies
- Population
Patients with IDA
- Country
UK, USA, Italy, Turkey, Iran, Israel
- Period
Searches to July 2017
- Sample size
18 studies, 2998 patients
- Inclusion and exclusion criteria
Studies reporting biopsy-verified coeliac disease in IDA
4. Methods and endpoints
- Exposure / intervention
IDA
- Comparator
none
- Endpoints
Prevalence of coeliac disease
- Statistical methods
Fixed-effects inverse-variance pooled prevalence; meta-regression
5. Actual results
- Results
Crude prevalence 4.8% (143/2998); weighted pooled prevalence 3.2% (2.6-3.9), I2 67.7%; in 8 high-quality studies 5.5% (4.1-6.9).
- Absolute risks
About 1 in 31 IDA patients has coeliac disease
- Authors' conclusion
About 1 in 31 IDA patients has histologic coeliac disease; testing IDA patients is justified.
6. Strengths
- Biopsy-confirmed
- Includes Middle-Eastern studies
7. Weaknesses
- Fixed-effects despite heterogeneity
- Referral populations
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Fixed-effect model with I2 68% narrows CI.
9. Assessment of the statistical interpretation
Recalculated crude 4.77% and 1 in 31 (stats/C-WHT-02).
10. Relevance to the specific claim
Iron-deficiency anaemia attributed by the claim to "flour glue" is in about 3-5% of cases due to coeliac disease, a diagnosable disease.
11. Independent contrary findings
None.
12. Transferability to Germany and Europe
High.
13. Overall methodological judgement
Solid evidence for testing.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | moderate |
| 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
None.