A Guide to Aid the Selection of Diagnostic Tests

In recent years, a wide range of diagnostic tests has become available for use in\ud resource-constrained settings. Accordingly, a huge number of guidelines, performance\ud evaluations and implementation reports have been produced. However, this wealth of\ud information is unstructured and of uneven quality, which has made it difficult for endusers,\ud such as clinics, laboratories and health ministries, to determine which test would\ud be best for improving clinical care and patient outcomes in a specific context. This paper\ud outlines a six-step guide to the selection and implementation of in vitro diagnostic tests\ud based on Médecins Sans Frontières’ practical experience: (i) define the test’s purpose;\ud (ii) review the market; (iii) ascertain regulatory approval; (iv) determine the test’s\ud diagnostic accuracy under ideal conditions; (v) determine the test’s diagnostic accuracy\ud in clinical practice; and (vi) monitor the test’s performance in routine use. Gaps in the\ud information needed to complete these six steps and in regulatory systems are\ud highlighted. Finally, ways of improving the quality of diagnostic tests are suggested,\ud such as establishing a model list of essential diagnostics, establishing a repository of\ud information on the design of diagnostic studies and improving quality control and\ud postmarketing surveillance