Simple statistics in diagnostic tests

Abstract

Diagnostic performance of a laboratory test is one of the key elements in decision making on diagnosis, screening, monitoring, risk assessment and prognosis of diseases. Sensitivity, specificity, likelihood ratios, diagnostic odds ratios and receiver operating characteristic curves are the measures of diagnostic accuracy of a test. The pretest probability of a disease or a target condition can be enhanced by the use of these measures, and hence the decision is made with the posttest probability. These measures are also used for analysis and critical appraisal of literature for finding the best evidence in the five-step model of evidence-based medicine approach, as well as for integrating the research results into clinical usage. In this context, the specialists in laboratory medicine should assess the diagnostic performance of a laboratory test as well as its analytical performance in order to take part in the management of health care services and health care resources. The aim of this review is to summarize the simple Statistics in diagnostic tests.