Cohort studycited by the Tayebat archivefull text checked★ key study A-ORG-13 in-depth review
Nurses' Health Study: removing both ovaries at hysterectomy
Long-term mortality associated with oophorectomy compared with ovarian conservation in the nurses' health study.
Overview
Parker WH et al.. Obstet Gynecol 2013 · PMID 23635669 · DOI 10.1097/AOG.0b013e3182864350
Removing the ovaries was linked to somewhat higher death rates (16.8% vs 13.3% over 28 years), mainly in women under 50 who never took estrogen.
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?
Mortality
- How was the study done?
Prospective cohort
- How many people, animals or samples were studied?
30,117
- What was actually found?
Higher mortality, especially <50 without estrogen
- How large was the observed effect?
HR 1.13; NNH 8 in subgroup
- What do the results mean in everyday life?
Keeping healthy ovaries may be better for many women
- What are the study's limitations?
Observational
- What does it say about Elawady's specific claim?
Supports direction; NNH misused
- Do the results apply to Germany and Europe?
Applicable
- What can explicitly not be concluded from this study?
Causation; women with BRCA etc.
Scientific in-depth review
1. Full reference
- Authors
- Parker WH, Feskanich D, Broder MS, Chang E, Shoupe D, Farquhar CM, Berek JS, Manson JE
- Journal
- Obstet Gynecol
- Year
- 2013
- Identifier
- PMID 23635669 DOI 10.1097/AOG.0b013e3182864350 · PMC4254662
- Verification
- verified (PMID in archive was wrong, corrected) – 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: NCI NIH HHS, NHLBI NIH HHS
2. Research question
Long-term mortality after bilateral oophorectomy vs ovarian conservation at hysterectomy
3. Study design and population
- Study design
- Cohort study – Prospective cohort (Nurses' Health Study)
- Population
NHS participants with hysterectomy for benign disease
- Country
USA
- Period
28 years follow-up
- Sample size
30,117 (16,914 oophorectomy; 13,203 conservation)
- Inclusion and exclusion criteria
Excluded prior cancers, CHD, stroke, PE, unilateral oophorectomy (full text)
4. Methods and endpoints
- Exposure / intervention
Bilateral oophorectomy
- Comparator
Ovarian conservation
- Endpoints
Cause-specific and all-cause mortality
- Statistical methods
Multivariable Cox; NNH assuming 35-year lifespan
5. Actual results
- Results
All-cause death 16.8% vs 13.3% (HR 1.13, 1.06-1.21). Lower ovarian cancer deaths (4 vs 44) and, before 47.5 years, lower breast cancer death. In women <50 who never used estrogen: all-cause HR 1.41 (1.04-1.92) with NNH 8 (full text); CHD death NNH 33, lung cancer death NNH 50. No increase in past/current estrogen users (HR 1.05).
- Absolute risks
16.8% vs 13.3% all-cause death over 28 years
- Authors' conclusion
Bilateral oophorectomy associated with increased mortality in women <50 who never used estrogen; at no age associated with increased survival.
6. Strengths
- Large prospective cohort
- Long follow-up
7. Weaknesses
- Observational; reasons for oophorectomy unknown (authors' limitation)
- Self-reported oophorectomy (>90% accurate)
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
Main support for C-ORG-09.
11. Independent contrary findings
Hassan 2024 meta-analysis: mortality heterogeneous (I2 85%).
12. Transferability to Germany and Europe
Applicable.
13. Overall methodological judgement
Correct direction; NNH misquoted and over-generalized.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified (PMID in archive was wrong, corrected) |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | moderate |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | partly correct but over-interpreted |
14. Open questions
15. Linked fact checks
- Bilateral oophorectomy at hysterectomy for benign disease increases all-cause mortality, coronary disease and lung cancer — roughly one extra death per nine operations (Parker 2013, Nurses' Health Study). – Studies supporting the claim
- Long-term registry data link removal of tonsils, appendix, gallbladder, uterus, ovaries and spleen to higher rates of respiratory disease, autoimmunity, cardiovascular events, gastrointestinal cancers and dementia; each organ does work the body never fully replaces. – Studies supporting 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
Bilateral oophorectomy raised all-cause mortality, CHD and lung cancer — roughly one extra death per 9 operations over 35 years.
- A. What was actually studied?
Oophorectomy vs ovarian conservation
- B. What did the authors find?
Overall HR 1.13; NNH 8 only in women <50 never using estrogen
- C. What conclusions do the authors themselves draw?
Increased mortality in <50 never-ET users; no survival benefit at any age
- D. What does the archive derive from it?
Used to show the price of removing ovaries.
- E. Is this derivation scientifically justified?
Direction correct. The 'one extra death per 9 operations' is not in the paper: the paper reports NNH 8, and only for the subgroup of women <50 who never used estrogen; it does not apply to all oophorectomies. Archive PMID was wrong; corrected in register.
- Adequacy of the interpretation (by the archive)
- partly correct but over-interpreted