Likelihood ratios: clinical application in day-to-day practice

Indian J Ophthalmol. 2009 May-Jun;57(3):217-21. doi: 10.4103/0301-4738.49397.


In this article we provide an introduction to the use of likelihood ratios in clinical ophthalmology. Likelihood ratios permit the best use of clinical test results to establish diagnoses for the individual patient. Examples and step-by-step calculations demonstrate the estimation of pretest probability, pretest odds, and calculation of posttest odds and posttest probability using likelihood ratios. The benefits and limitations of this approach are discussed.

MeSH terms

  • Diagnostic Techniques, Ophthalmological / statistics & numerical data*
  • Eye Diseases / diagnosis*
  • False Negative Reactions
  • Humans
  • Likelihood Functions*
  • Predictive Value of Tests
  • Professional Practice
  • Sensitivity and Specificity