Cohort studycited by the Tayebat archivefull text checked A-BAR-01 in-depth review
Short-term safety of weight-loss surgery in the US
Perioperative safety in the longitudinal assessment of bariatric surgery.
Overview
Flum DR et al.. N Engl J Med 2009 · PMID 19641201 · DOI 10.1056/NEJMoa0901836
About 3 in 1000 patients died within 30 days; 4.3% had a serious complication.
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?
Measure early risks
- How was the study done?
Prospective multicentre cohort
- How many people, animals or samples were studied?
4776 adults
- What was actually found?
Low early mortality (0.3%)
- How large was the observed effect?
30-day death 0.3%
- What do the results mean in everyday life?
Serious early complications are uncommon but real
- What are the study's limitations?
Only 30 days; sleeve operations excluded; experienced centres; no non-surgical comparison
- What does it say about Elawady's specific claim?
Does not support 'lethal'; documents a small real risk
- Do the results apply to Germany and Europe?
Similar to European data
- What can explicitly not be concluded from this study?
Long-term effects
Scientific in-depth review
1. Full reference
- Authors
- Longitudinal Assessment of Bariatric Surgery (LABS) Consortium, Flum DR, Belle SH, King WC, Wahed AS, Berk P, Chapman W, Pories W, Courcoulas A, McCloskey C, Mitchell J, Patterson E, Pomp A, Staten MA, Yanovski SZ, Thirlby R, Wolfe B
- Journal
- N Engl J Med
- Year
- 2009
- Identifier
- PMID 19641201 DOI 10.1056/NEJMoa0901836 · PMC2854565
- Verification
- verified – PubMed E-utilities efetch, 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- full text
- Conflicts of interest and funding
Funded by NIDDK (U01 grants). Several authors report industry grants/consulting/lecture fees (Covidien, Allergan, Ethicon, Johnson & Johnson, Pfizer, GSK, Lilly, Stryker, W.L. Gore, EnteroMedics) and some served as expert witnesses in bariatric adverse-event cases.
2. Research question
What is the 30-day risk of death and major adverse outcomes after bariatric surgery?
3. Study design and population
- Study design
- Cohort study – Prospective multicentre observational cohort of consecutive first-time bariatric operations (LABS-1)
- Population
Adults with extreme obesity (median BMI 46.5) undergoing first-time RYGB or LAGB
- Country
USA
- Period
March 11, 2005 - December 31, 2007
- Sample size
5648 approached; 4776 first-time procedures; 4610 analysed for outcomes (2975 laparoscopic RYGB, 437 open RYGB, 1198 LAGB); 166 others excluded (117 sleeve gastrectomy, 47 BPD/BPD-DS, 2 other)
- Inclusion and exclusion criteria
Consecutive patients >=18 years undergoing a first bariatric procedure by 33 LABS-certified surgeons at 10 US sites; procedures making up <3% of operations (sleeve gastrectomy, BPD/DS, VBG, open banding) excluded from outcome analyses
4. Methods and endpoints
- Exposure / intervention
RYGB or LAGB
- Comparator
Patient characteristics (no non-surgical comparator)
- Endpoints
30-day composite of death, VTE, reintervention, failure to be discharged
- Statistical methods
Chi-square/Kruskal-Wallis comparisons; generalized linear mixed models (random intercepts for site and surgeon) with stepwise selection (entry p<0.25, retention p<0.10); quadratic BMI term
5. Actual results
- Results
30-day deaths 15/4610 (0.3%): 0/1198 LAGB, 6/2975 (0.2%) LRYGB, 9/437 (2.1%) open RYGB. Composite endpoint 189/4610 (4.1%; abstract states 4.3%): 1.0% LAGB, 4.8% LRYGB, 7.8% open RYGB; most frequent components abdominal reoperation 2.6% and endoscopic intervention 1.1%. Adjusted: risk of composite endpoint 4.8-fold (LRYGB) and 5.8-fold (ORYGB) vs LAGB; ORYGB vs LRYGB OR 1.21 (95% CI 0.71-2.04). BMI 75 vs 53 kg/m2 OR 1.61 (95% CI 1.04-2.48). History of DVT/VTE, obstructive sleep apnea and inability to walk 200 ft independently associated; age, sex, race not. Predicted composite risk ranged from about 3% to over 10% depending on risk profile.
- Absolute risks
30-day mortality 0.3% overall (15/4610; 0% LAGB, 0.2% LRYGB, 2.1% open RYGB); composite major adverse outcome 4.1% in Table 2 (189/4610) vs 4.3% in abstract
- Authors' conclusion
Overall risk of death and adverse outcomes was low and varied with patient characteristics; short-term safety should be weighed against long-term effects and risks of extreme obesity.
6. Strengths
- Prospective, consecutive patients, standardized definitions and certified data collectors
- Large multicentre sample (10 sites, 33 surgeons)
- Mixed models accounting for clustering by site and surgeon
7. Weaknesses
- Only 30-day outcomes
- Sleeve gastrectomy (n=117) excluded from outcome analyses
- No non-surgical control
- Experienced certified centres; generalisability to community practice unknown (stated by authors)
- Comorbidities self-reported
- Stepwise variable selection; limited power for some subgroups (Type II error acknowledged)
- Composite endpoint inclusive of reoperation biases against anastomotic procedures (authors)
- Minor internal inconsistency: composite 4.3% (abstract) vs 4.1% (Table 2)
8. Risk of bias
- Orienting tool
- ROBINS-E (adapted for a descriptive safety cohort / risk-factor analysis)
- Type of assessment
- structured assessment based on the full text by a single reviewer (no formal double review)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Low risk of bias for the descriptive 30-day estimates; between-procedure comparisons are confounded by indication. Structured single-reviewer judgement from full text; a formal assessment would require two independent reviewers and a protocol.
| Domain | Judgement | Rationale |
|---|---|---|
| Confounding | not applicable | Main estimates are descriptive 30-day incidences; procedure comparisons adjusted, but procedure choice is confounded by severity (open RYGB patients sicker). |
| Exposure measurement | low | Procedure type recorded prospectively. |
| Selection of participants | some concerns | Consecutive patients but 5648 approached vs 4776 operated; experienced certified surgeons only; possible preferential selection of healthier patients acknowledged. |
| Post-exposure interventions | not applicable | Short-term outcome. |
| Missing data | low | 30-day outcomes collected on essentially all analysed patients; little missing baseline data. |
| Outcome measurement | low | Objective, standardized composite (death, VTE, reintervention, non-discharge); postoperative bleeding without reintervention not captured. |
| Selection of reported result | low | Prespecified composite endpoint; small abstract/table inconsistency (4.3% vs 4.1%). |
Full-text review (25 October 2026): Added procedure-specific mortality (0%, 0.2%, 2.1%), counts (15/4610 deaths; 189/4610 composite = 4.1% vs 4.3% in abstract), adjusted ORs with CIs, exclusion of 117 sleeve cases, industry COI of several authors; bias domains added, overall unchanged (low).
9. Assessment of the statistical interpretation
Absolute short-term risks are directly reported.
10. Relevance to the specific claim
Shows that perioperative mortality is low; relevant to the claim that sleeve/bariatric surgery is 'lethal'.
11. Independent contrary findings
Consistent with SOReg (A-BAR-12) and SOS (A-BAR-05).
12. Transferability to Germany and Europe
Comparable to European registries (SOReg).
13. Overall methodological judgement
Reliable short-term safety data; contradicts a general 'lethal operation' claim but does not address long-term harms.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | high |
| Directness | indirect |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Sleeve-specific 30-day risk not analysed (117 sleeve patients excluded); long-term mortality not addressed; community-practice risks.
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
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
Listed in the archive bibliography only; the archive gives no specific interpretation.
- A. What was actually studied?
30-day safety of RYGB and LAGB
- B. What did the authors find?
0.3% 30-day mortality; 4.3% major adverse outcomes
- C. What conclusions do the authors themselves draw?
Risk low, varies by patient factors
- D. What does the archive derive from it?
None explicit; listed under risks.
- E. Is this derivation scientifically justified?
Not applicable; if used to suggest high lethality it would contradict the study.
- Adequacy of the interpretation (by the archive)
- not applicable