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Record W1981535675 · doi:10.1136/bmj.328.7431.67

Three journals raise doubts on validity of Canadian studies

2004· article· en· W1981535675 on OpenAlexaboutno aff
Caroline White

Bibliographic record

VenueBMJ · 2004
Typearticle
Languageen
FieldAgricultural and Biological Sciences
TopicNutrition, Health, and Society Studies
Canadian institutionsnot available
Fundersnot available
KeywordsMedicineMultivitaminPlaceboAlternative medicineGerontologyFamily medicinePathology

Abstract

fetched live from OpenAlex

Suspicions about the validity of research by Professor Ranjit Kumar Chandra, a prominent Canadian researcher, have been raised by three journals, including the BMJ . The latest concern, in an editorial and a letter in the November issue of Nutrition (2003;19: 955-6 and 976-80) question research published in that journal by Professor Chandra in September 2001 (17:709-12). The Nutrition study was a randomised, blind, placebo controlled trial. It showed that a specific multivitamin and mineral supplement could improve cognitive function in people aged over 65 years. Professor Chandra, who was the sole author, concluded that the supplement might delay the onset of Alzheimer's disease. The original paper and the most recent letter and editorial questioning its validity have attracted considerable media attention. > The BMJ's statistical reviewer concluded that the data had “all the hallmarks of being entirely invented.” The 2001 paper in Nutrition is almost identical to a paper submitted to the BMJ in October 2000, which followed up a trial published in the Lancet in 1992 (340: 1124-7) The BMJ paper was not published because of serious problems identified during peer review. These problems included the lengthy period between the Lancet trial and submission of the manuscript on the same set of data to the BMJ and doubts that a major trial could have been undertaken by one man, who, …

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.731
Threshold uncertainty score0.961

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.226
GPT teacher head0.354
Teacher spread0.129 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations35
Published2004
Admission routes1
Has abstractyes

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Same venueBMJSame topicNutrition, Health, and Society StudiesFrench-language works237,207