Evidence for non‐random sampling in randomised, controlled trials by Yuhji Saitoh
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Summary: A large number of randomised trials authored by Yoshitaka Fujii have been retracted, in part as a consequence of a previous analysis finding a very low probability of random sampling. Dr Yuhji Saitoh co‐authored 34 of those trials and he was corresponding author for eight of them. We found a number of additional randomised, controlled trials that included baseline data, with Saitoh as corresponding author, that Fujii did not co‐author. We used Monte Carlo simulations to analyse the baseline data from 32 relevant trials in total as well as an outcome (muscle twitch recovery ratios) reported in several. We also compared a series of muscle twitch recovery graphs appearing in a number of Saitoh's publications. The baseline data in 14/32 randomised, controlled trials had p < 0.01, of which seven p values were < 0.001. Eight trials reported four ratios of the time for the return of muscle activity after neuromuscular blockade, the distributions of which were homogeneous: the p values for the observed Q statistics were 0.0055, 0.031, 0.016 and 0.0071. Comparison of graphs revealed multiple coincident or near‐coincident curves across a large number of publications, a finding also inconsistent with random sampling. Combining the continuous and categorical probabilities of the 32 included trials, we found a very low likelihood of random sampling: p = 1.27 × 10 −8 (1 in 100,000,000). The high probability of non‐random sampling and the repetition of lines in multiple graphs suggest that further scrutiny of Saitoh's work is warranted.
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The same approach has been used to investigate trials published by Yuhji Saitoh, a co-author of Dr Fujii, and formed a component of the investigation of his work.
“The same approach has been used to investigate trials published by Yuhji Saitoh, a co-author of Dr Fujii, and form a component of the investigation of his work [4].”
From Data fabrication and other reasons for non‐random sampling in 5087 randomised, controlled trials in anaesthetic and general medical journals (2017) · cites this paper as [4]
The trials published by Yuhji Saitoh were identified as problematic by Carlisle and colleagues.
“I used the trials published by Yuhji Saitoh which were identified as problematic by Carlisle and colleagues. 22”
From Automated detection of over- and under-dispersion in baseline tables in randomised controlled trials. (2022) · cites this paper as [22]
A limitation of GRIMMER software is that it only works for sample sizes of 99 or less.
“A limitation of the software is that it only works for a sample size of 99 or less.”
From Assessing Research Misconduct in Randomized Controlled Trials (2021) · cites this paper as [21]
The GRIMMER test assesses whether reported measures of variability are possible given the sample size and granularity.
“The GRIMMER (Granularity-Related Inconsistency of Means Mapped to Error Repeats) test allows for testing whether reported measures of variability are possible by assessing whether a reported statistic is consistent with the sample size and granularity.20,21”
From Assessing Research Misconduct in Randomized Controlled Trials (2021) · cites this paper as [21]
GRIMMER can test variances, standard deviations, and standard errors.
“This method can test variances, SDs, and standard errors.”
From Assessing Research Misconduct in Randomized Controlled Trials (2021) · cites this paper as [21]
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1 retracted
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Self-citationExtreme between-study homogeneity in meta-analyses could offer useful insights
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Flagged first, then by citations
Research works printed but not linked: 1
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- Authors
- Carlisle, J. B., & Loadsman, J. A.
- Affiliations
- Torbay Hospital (GB)
- The University of Sydney (AU)
- Corresponding author
- Carlisle, J. B.
- Venue
- Anaesthesia
- Publisher
- Wiley
- Published
- 2016-12-18
- Volume
- 72
- Issue
- 1
- Pages
- 17-27
- ISSN
- 0003-2409 (ISSN-L)
- 1365-2044
- OpenAlex
- W2566467546
- Semantic Scholar
- 5f76e10c8e2cd2f644f5f3982499a330114f4b33
- Cited by
- 64
- References
- 5
- Citations by year
- 2026: 3 · 2025: 6 · 2024: 7 · 2023: 3 · 2022: 4 · 2021: 7 · 2020: 8 · 2019: 8 · 2018: 5 · 2017: 12 · 2016: 1
- FWCI
- 21.96
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Anaesthesia (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Social Sciences › Safety Research › Academic integrity and plagiarism
- Physical Sciences › Mathematics › Statistics and Probability › Benford’s Law and Fraud Detection
- Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmacology › Pharmaceutical industry and healthcare
- Keywords
- non-probability sampling, randomized controlled trials, corresponding authorship, baseline data, p-values, neuromuscular blockade, q-statistics, research integrity
- MeSH terms
- Adult, Data Interpretation, Statistical, Female, Humans, Male, Middle Aged, Monte Carlo Method, Random Allocation, Research Design, Scientific Misconduct, Randomized Controlled Trials as Topic, Neuromuscular Blockade
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