Cohort studyindependent cross-checkabstract only checked I-BAR-08 standard review
Swedish study: fractures after gastric bypass
Fracture Risk After Gastric Bypass Surgery: A Retrospective Cohort Study.
Overview
Axelsson KF et al.. J Bone Miner Res 2018 · PMID 30011091 · DOI 10.1002/jbmr.3553
Fracture risk was about 26-32% higher than in similar people without surgery.
Does the study support the specific claim? Yes · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Fracture
- How was the study done?
Matched cohort
- How many people, animals or samples were studied?
~78,000
- What was actually found?
Higher risk
- How large was the observed effect?
HR 1.26-1.32
- What do the results mean in everyday life?
Bone protection is important after bypass
- What are the study's limitations?
Short follow-up
- What does it say about Elawady's specific claim?
Supports (bypass)
- Do the results apply to Germany and Europe?
European
- What can explicitly not be concluded from this study?
Sleeve risk
Scientific in-depth review
1. Full reference
- Authors
- Axelsson KF et al.
- Journal
- J Bone Miner Res
- Year
- 2018
- Identifier
- PMID 30011091 DOI 10.1002/jbmr.3553
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract
2. Research question
Fracture risk after gastric bypass
3. Study design and population
- Study design
- Cohort study – Retrospective propensity-matched cohort
- Population
Swedish obese patients
- Country
Sweden
- Sample size
38,971 bypass + equal matched controls
4. Methods and endpoints
- Exposure / intervention
Gastric bypass
- Comparator
Propensity-matched obese controls
- Endpoints
Fracture, fall injury
5. Actual results
- Results
Any fracture HR 1.26 (1.05-1.53) with diabetes and 1.32 (1.18-1.47) without; risk increased with time; fall injuries also increased; not associated with weight loss or Ca/vit D supplementation.
- Absolute risks
not reported
- Authors' conclusion
Gastric bypass associated with increased fracture risk increasing with time.
6. Strengths
- Large national data
7. Weaknesses
- Median follow-up 3.1 years
8. Risk of bias
- Orienting tool
- ROBINS-E
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
9. Assessment of the statistical interpretation
10. Relevance to the specific claim
Supports C-BAR-06 for RYGB.
11. Independent contrary findings
12. Transferability to Germany and Europe
Directly European.
13. Overall methodological judgement
Supports.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| 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
15. Linked fact checks
- Bariatric surgery causes measurable hip and spine bone loss (and fracture risk). – Studies supporting the claim
- Gastric bypass is preferable to sleeve gastrectomy (less reflux) and can fully treat type 2 diabetes; for patients who fail dieting, bypass rather than sleeve should be chosen (2021 statement). – Studies contradicting or limiting the claim