Statistical methods for conducting agreement (comparison of clinical tests) and precision (repeatability or reproducibility) studies in optometry and ophthalmology

Colm McAlinden, Jyoti Khadka, Konrad Pesudovs

Research output: Contribution to journalReview articlepeer-review

247 Citations (Scopus)


The ever-expanding choice of ocular metrology and imaging equipment has driven research into the validity of their measurements. Consequently, studies of the agreement between two instruments or clinical tests have proliferated in the ophthalmic literature. It is important that researchers apply the appropriate statistical tests in agreement studies. Correlation coefficients are hazardous and should be avoided. The 'limits of agreement' method originally proposed by Altman and Bland in 1983 is the statistical procedure of choice. Its step-by-step use and practical considerations in relation to optometry and ophthalmology are detailed in addition to sample size considerations and statistical approaches to precision (repeatability or reproducibility) estimates.

Original languageEnglish
Pages (from-to)330-8
Number of pages9
JournalOphthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)
Issue number4
Publication statusPublished or Issued - Jul 2011
Externally publishedYes


  • Humans
  • Ophthalmology
  • Optometry
  • Qualitative Research
  • Reproducibility of Results
  • Vision, Ocular
  • Journal Article
  • Review

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