Statistics Notes: Diagnostic tests 1: sensitivity and specificityBMJ 1994; 308 doi: https://doi.org/10.1136/bmj.308.6943.1552 (Published 11 June 1994) Cite this as: BMJ 1994;308:1552
- D G Altman,
- J M Bland
- Medical Statistics Laboratory, Imperial Cancer Research Fund, London WC2A 3PX
- Department of Public Health Sciences, St George's Hospital Medical School, London SW17 0RE.
The simplest diagnostic test is one where the results of an investigation, such as an x ray examination or biopsy, are used to classify patients into two groups according to the presence or absence of a symptom or sign. For example, the table shows the relation between the results of a test, a liver scan, and the correct diagnosis based on either necropsy, …