Evaluation of Diagnostic and Screening Test in Veterinary Medicine

Screening tests are a special type of diagnostic tests that are performed in an apparently healthy population. The purpose of performing diagnostic tests is to correctly diagnose patients, distinguish affected animals from healthy animals, distinguish between cases and controls, and distinguish between normal and abnormal cases. Screening tests should be simple, cheap, rapid and valid. Diagnostic and screening tests are mainly used in the monitoring of diseases. Related terms to the evaluation of these tests, including sensitivity, specificity, positive and negative predictive value, accuracy and precision, as well as concepts such as the golden standard, because they are often used interchangeably or misinterpreted, it is especially important to learn them. Also, due to the fact that gold standard tests are often more expensive and time-consuming, incomplete diagnostic tests are used, which can be calculated by calculating the sensitivity and specificity of the actual and apparent prevalence obtained by the diagnostic test. However, if the golden standard test is not available, other methods are used to evaluate the tests, including the Kappa index test. The interpretation results of these tests provide a comprehensive and evidence-based approach to clinicians and experts, which ultimately leads to more accurate, comprehensive, cheaper and faster monitoring. In this review article, with a complete and comprehensive review of the conventional concepts in the evaluation of diagnostic tests, along with the solution of practical examples, we will expand and provide a comprehensive presentation of these concepts. Also, the latest original studies that have been done in the field of evaluation of diagnostic tests will also be reviewed in this article.