Cohort studycited by the Tayebat archivefull text checked★ key study A-BAR-05 in-depth review
Swedish 24-year study: surgery added about 3 years of life
Life Expectancy after Bariatric Surgery in the Swedish Obese Subjects Study.
Overview
Carlsson LMS et al.. N Engl J Med 2020 · PMID 33053284 · DOI 10.1056/NEJMoa2002449
Operated patients lived about 3 years longer than non-operated patients with obesity, but still about 5.5 years less than the general population (non-operated: about 8.5 years less).
Does the study support the specific claim? Partly · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Life expectancy
- How was the study done?
Prospective controlled cohort with population reference
- How many people, animals or samples were studied?
5182 people
- What was actually found?
Surgery gained 3 years; gap to population 5.5 vs 8.5 years
- How large was the observed effect?
HR death 0.77; +3.0 years
- What do the results mean in everyday life?
Surgery reduced but did not remove the life-expectancy loss linked to severe obesity
- What are the study's limitations?
Not randomized; old operations
- What does it say about Elawady's specific claim?
Number correct, implication 'surgery shortens life' wrong
- Do the results apply to Germany and Europe?
Directly European
- What can explicitly not be concluded from this study?
That surgery causes the remaining 5.5-year gap
Scientific in-depth review
1. Full reference
- Authors
- Carlsson LMS, Sjöholm K, Jacobson P, Andersson-Assarsson JC, Svensson PA, Taube M, Carlsson B, Peltonen M
- Journal
- N Engl J Med
- Year
- 2020
- Identifier
- PMID 33053284 DOI 10.1056/NEJMoa2002449 · PMC7580786
- Verification
- verified – PubMed E-utilities efetch, 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- full text
- Conflicts of interest and funding
COI: not stated in record | Grants: NIDDK NIH HHS, Novo Nordisk Fonden, United States
2. Research question
Effect of bariatric surgery on life expectancy vs usual care and vs general population
3. Study design and population
- Study design
- Cohort study – Prospective controlled (non-randomized) SOS study plus random general-population reference cohort; Gompertz modelling of life expectancy
- Population
Swedish adults with obesity; general-population reference sample
- Country
Sweden
- Period
Recruitment 1987-2001; follow-up to 31 Dec 2018
- Sample size
2007 surgery, 2040 controls, 1135 reference
- Inclusion and exclusion criteria
SOS matching criteria; non-randomized because of 1980s ethical concerns about operative mortality (full text)
4. Methods and endpoints
- Exposure / intervention
Bariatric surgery (mostly VBG, banding, some bypass)
- Comparator
Usual obesity care; general population
- Endpoints
Mortality, cause-specific death, life expectancy
- Statistical methods
Gompertz proportional hazards; adjusted median life expectancy
5. Actual results
- Results
Deaths 457 (22.8%) surgery vs 539 (26.4%) control; HR 0.77 (0.68-0.87). CVD death HR 0.70 (0.57-0.85); cancer death HR 0.77 (0.61-0.96). Adjusted median life expectancy +3.0 years (1.8-4.2) vs controls, but 5.5 years (3.4-7.6) shorter than reference cohort. Full text: controls' life expectancy was 8.5 years (6.4-10.5) shorter than the reference cohort (adjusted); non-disease deaths (alcoholism, suicide, trauma) 38 vs 20, HR 1.85 (1.08-3.17). 90-day postoperative mortality 0.2%.
- Absolute risks
Deaths 22.8% vs 26.4% over ~24 years
- Authors' conclusion
Bariatric surgery associated with longer life expectancy than usual care; mortality remained higher in both groups than in the general population.
6. Strengths
- Very long follow-up (median 24 y)
- 99.9% mortality data
- General-population reference
7. Weaknesses
- Not randomized
- Old procedures; little sleeve data
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
- Rationale
Non-randomized allocation; adjusted analyses; residual confounding possible.
9. Assessment of the statistical interpretation
The 5.5-year gap to the general population reflects persistent obesity-related risk; without surgery the gap was about 8.5 years. Surgery narrowed, not created, the gap.
10. Relevance to the specific claim
Central to the SOS claim (C-BAR-10) and to the 'lethal' claim (C-BAR-01).
11. Independent contrary findings
Meta-analysis I-BAR-01 (+6.1 years).
12. Transferability to Germany and Europe
Directly European.
13. Overall methodological judgement
High-value long-term evidence. Archive narrative accurate; summary framing incomplete.
| 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) | essentially correct but incomplete |
14. Open questions
Life expectancy effect of sleeve gastrectomy specifically.
15. Linked fact checks
- Sleeve gastrectomy (and bariatric surgery in general) is a lethal operation that kills patients / shortens life. – Studies contradicting or limiting the claim
- Even the largest long-term study (SOS) showed that surgery patients still die 5.5 years earlier than the general population. – Studies supporting the claim
- Sleeve gastrectomy is a physiologically wrong operation and a 'transgression against God's creation', because the stomach is not a bag but an endocrine, muscular and immune organ whose functions are lost. – Studies contradicting or limiting the claim
- Sleeve gastrectomy makes cancer appear decades earlier (it 'kills' and brings cancer forward). – Studies contradicting or limiting the claim
Use by the Tayebat archive
Note: according to the archive, the studies were compiled by the archive operators. Whether Dr. Elawady himself cited this study is not established.
- What the archive says about the study
SOS surgery patients lived a median 3 years longer than controls, yet still died 5.5 years earlier than the general population. Summary: 'Even the largest long-term trial (SOS) showed that surgery patients still die 5.5 years earlier than the general population.'
- A. What was actually studied?
Life expectancy after surgery vs usual care vs general population
- B. What did the authors find?
+3.0 years vs usual care; -5.5 years vs general population; controls -8.5 years
- C. What conclusions do the authors themselves draw?
Surgery associated with longer life; mortality remained above general population
- D. What does the archive derive from it?
The featured card and narrative correctly report both numbers. The rule summary mentions only the 5.5-year gap and calls SOS a 'trial'.
- E. Is this derivation scientifically justified?
Numbers correct. The summary sentence, read alone, could suggest that surgery shortens life; the study shows the opposite (surgery narrowed an 8.5-year gap to 5.5 years). SOS is a non-randomized controlled study, not a randomized trial.
- Adequacy of the interpretation (by the archive)
- essentially correct but incomplete