Cited by 9,619Reliability and Agreement in MeasurementClinical Laboratory Practices and Quality ControlMeta-analysis and systematic reviews

Measuring agreement in method comparison studies

Bland, J Martin, Altman, Douglas G·1999·Statistical Methods in Medical Research

Abstract

Agreement between two methods of clinical measurement can be quantified using the differences between observations made using the two methods on the same subjects. The 95% limits of agreement, estimated by mean difference 1.96 standard deviation of the differences, provide an interval within which 95% of differences between measurements by the two methods are expected to lie. We describe how graphical methods can be used to investigate the assumptions of the method and we also give confidence intervals. We extend the basic approach to data where there is a relationship between difference and magnitude, both with a simple logarithmic transformation approach and a new, more general, regression approach. We discuss the importance of the repeatability of each method separately and compare an estimate of this to the limits of agreement. We extend the limits of agreement approach to data with repeated measurements, proposing new estimates for equal numbers of replicates by each method on each subject, for unequal numbers of replicates, and for replicated data collected in pairs, where the underlying value of the quantity being measured is changing. Finally, we describe a nonparametric approach to comparing methods.

Integrity signals

Registry

Crossref · 10.1177/096228029900800204

Cites

25 of 25 references verified0 citation errors · 0 not checkable

Statistics

Recomputing p-values needs the paper’s full text.

Claims the paper makes

This paper’s full text isn’t openly available, so its claims and self-check weren’t run. The registry and citation checks still apply.

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • For calculations comparing active and passive trials, the mean of the Moxy passive trials was used against the corresponding active trial and proper adjustments to SD were made as proposed by Bland and Altman.

    “For the calculations, the mean of the Moxy passive trials was used against the corresponding active trial and therefore proper adjustments to SD were made as proposed by Bland and Altman.40”
  • In the non-constant case, the variance for single differences between pairs of measurements on different subjects is found by summing the between-subjects and within-subjects variances.

    “The variance for single differences between pairs of measurements on different subject is found by summing the between subjects and within subjects variances (Bland and Altman 1999).”

    From Agreement Between Methods of Measurement with Multiple Observations Per Individual (2007) · cites this paper as Bland and Altman 1999

  • In Bland and Altman (1999), we incorrectly stated that this number should be used to multiply the difference in the sum of squares, rather than divide it.

    “(In our earlier paper (Bland and Altman 1999), we incorrectly stated that this number should be used to multiply the difference in the sum of squares, rather than divide it.)”

    From Agreement Between Methods of Measurement with Multiple Observations Per Individual (2007) · cites this paper as Bland and Altman 1999

  • Obtaining replicate measurements by each method on each individual allows the repeatability of the two methods to be compared.

    “It is valuable, however, to obtain replicate measurements by each method on each individual so that the repeatability of the two methods can be compared (Bland and Altman 1999).”

    From Agreement Between Methods of Measurement with Multiple Observations Per Individual (2007) · cites this paper as Bland and Altman 1999

  • Although these methods have been described previously (Bland and Altman 1999), no numerical example was given for the case when the true value varied, and there was an error in the mathematical description.

    “Although these have been described previously (Bland and Altman 1999) no numerical example was given for the case when the true value of the quantity being measured varied and also there was an error in the mathematical description.”

    From Agreement Between Methods of Measurement with Multiple Observations Per Individual (2007) · cites this paper as Bland and Altman 1999

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Authors
Bland, J. M., & Altman, D. G.
Affiliations
  • St George's, University of London (GB)
  • University of Oxford (GB)
Venue
Statistical Methods in Medical Research
Published
1999-04
Volume
8
Issue
2
Pages
135-160
ISSN
  • 0962-2802 (ISSN-L)
  • 1477-0334
OpenAlex
W2159759971
Cited by
9,619
References
25
Citations by year
2026: 393 · 2025: 421 · 2024: 483 · 2023: 494 · 2022: 559 · 2021: 681 · 2020: 610 · 2019: 506 · 2018: 485 · 2017: 457 · 2016: 412 · 2015: 437 · 2014: 461 · 2013: 388 · 2012: 401
FWCI
47.68
Type
journal article
Language
en
Open access
closed
Locations
  • Statistical Methods in Medical Research (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Reliability and Agreement in Measurement
  • Health Sciences › Medicine › Physiology › Clinical Laboratory Practices and Quality Control
  • Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
Keywords
method comparison, measurement agreement, limits of agreement, mean difference, repeatability, regression analysis, logarithmic transformation, repeated measures, nonparametric comparison, graphical method, confidence intervals
MeSH terms
Humans, Medical Laboratory Science, Reproducibility of Results, Confidence Intervals, Linear Models, Statistics, Nonparametric, Clinical Laboratory Techniques

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