Table 1 Measures of accuracy of dichotomous test results

   The proportion of people with disease who are correctly identified as such.

   Specificity (true negative rate)

   The proportion of people with disease who are correctly identified as such.

   Positive predictive value

   The proportions of test positive people who truly have disease.

   Negative predictive value

   The proportions of test negative people who truly do not have disease.

   Likelihood ratios (LR)

   The ratio of the probability of a positive (or negative) test result in the patients with disease to the probability of the same test result in the patients without the disease.

   Diagnostic odds ratio

   The ratio of the odds of a positive test result in patients with disease compared to the odds of the same test result in patients without disease.

Measures for meta-analysis

   Summary sensitivity, Specificity, predictive values, likelihood ratios, and diagnostic odds ratio

   Pooling of the above accuracy measures obtained from multiple primary studies (usually averaged and weighted according to size of individual studies).

   Summary receiver operating characteristics curve (ROC)

   A method of summarising the performance of a test as found in multiple primary studies, which takes into account the relationship between sensitivity and specificity.