The DOI matches its Crossref record.
Correlation, regression, and repeated data: Authors' reply
Open accessAbstract
EDITOR, - J Martin Bland and Douglas G Altman's note on correlation, regression, and repeated measures draws attention to the problem of calculating a correlation coefficient based on repeated observations of the same subject.1 But they fall prey themselves to the common misjudgment of placing too much importance on the significance of the correlation coefficient. The basic problem is the way in which significance is calculated as the correlation coefficient is strongly affected by the number of cases for which there are pairs of data. If, for example, you have about 500 cases the correlation coefficient needs only to be 0.088 to be significant at …
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cited by
Correlation Coefficients: Appropriate Use and Interpretation
Schober, P., Boer, C., & Schwarte, L. A. (2018) · Anesthesia & Analgesia · doi:10.1213/ane.0000000000002864 · Cited by 10,986
Calculating correlation coefficients with repeated observations: Part 2—correlation between subjects
Bland, J. M., & Altman, D. G. (1995) · BMJ · doi:10.1136/bmj.310.6980.633 · Cited by 1,082
The problem of pseudoreplication in neuroscientific studies: is it affecting your analysis?
Lazic, S. E. (2010) · BMC Neuroscience · doi:10.1186/1471-2202-11-5 · Cited by 381
Individual Differences in Adult Human Sleep and Wakefulness: Leitmotif for a Research Agenda
van Dongen, H. P. A., Vitellaro, K. M., & Dinges, D. F. (2005) · Sleep · doi:10.1093/sleep/28.4.479 · Cited by 339
Kondo, D. G., Forrest, L. N., Shi, X., Sung, Y.-H., Hellem, T. L., Huber, R. S., & Renshaw, P. F. (2016) · Amino Acids · doi:10.1007/s00726-016-2194-3 · Cited by 79
Metadata
- Authors
- Persaud, R.
- Venue
- BMJ
- Publisher
- BMJ
- Published
- 1994-06-04
- Volume
- 308
- Issue
- 6942
- Pages
- 1510.2
- ISSN
- 0007-1447 (ISSN-L)
- 0959-8138
- 1468-5833
- OpenAlex
- W2095329410
- Cited by
- 159
- References
- 0
- Type
- journal article
- Language
- en
- Open access
- green
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
How to cite
Cite CoChat for the checks on this page, and the paper for its own findings.
- This page
- CoChat. (2026). Citation check: Correlation, regression, and repeated data: Authors' reply. https://app.cochat.ai/papers/10.1136/bmj.308.6942.1510a
- The paper
- Persaud, R. (1994). Correlation, regression, and repeated data: Authors' reply. BMJ. https://doi.org/10.1136/bmj.308.6942.1510a
Data sources
Bibliographic data: Semantic Scholar, OpenAlex, Crossref.
Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).
Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.
